NUC RAD SHARE

NUCLEAR MEDICINE PROTOCOLS 

 




NUCLEAR MEDICINE PROTOCOLS

COMPREHENSIVE NUC MED PROTOCOL GUIDE

 
Comprehensive nuclear medicine protocol guide for dose range patient preparation indications imaging tips camera protocol and study interpretation
DaT scan, Cisternogram, BSGI, Dacryoscintigraphy, Adreview, Milk scan, Peritoneal scintigraphy, NaF, Amyloid scan Amyvid, RN cystography, salivary scan, Thyroid I131 therapy dosimetric calculation, Xofigo, Y-90 radioembolization, Zevalin, Samarium

STUDY

DOSE/ROUTE

PATIENT PREP/INDICATIONS

IMAGING PROTOCOL/INTEPRETATION

BONE SCAN

Tc-HDP/MDP

20-30mCi IV

● Hydration before exam (16oz water)

 

Whole Body (WBBS)

-WB drag usually 7cm/min

-TOD view if significant retained bladder activity on post-void pelvis image

-Lateral views of tib/fib for suspected shin splints or stress fracture

-POW and oblique views for rib lesion

-SPECT (or SPECT/CT) is useful for skull/spine/pelvis lesion (64stops with 40s/stop with 128x128matrix)

 

2phase Whole body

-Whole body blood pool and 3-4hr delayed for inflammatory arthritis

-TcO4 is more specific for synovitis

 

3phase BS

-Inject radiotracer contralateral to affected extremity side

-Immediate dynamic flow 1s/frame x60s (64x64 matrix)

-Blood pool 5min static (or 300-500k counts; 256x256 matrix) within 10min of injection

-Delayed at 3-4hr post-injection

-3 phase positive BS is consistent with OM if no surgery/trauma/hardware 

-Some suggest for hardware evaluation 3phase BS no better than single phase delayed BS

-3 phase positive ddx: OM, trauma, recent surgery, inflammatory arthritis, neuropathic joint (charcot), RDS, tumor

-Normal cemented prosthesis can have uptake x1yr while porous prosthesis can have uptake x2yr

-Plantar fasciitis=positive BP (focal) predicts response to steroid injections

-CRPS may have normal flow and BP if >6mos to 1year (subacute and chronic)

-Peds OM: neonate or <6mos=false neg; infants=epiphysis; children 1-16yo= metaphysis (physis acts as a barrier)

 

INTERPRETATION:

-Beware of flare phenomenon within 2wks-3mos of chemotherapy (rare after 6mos)

-SI : sacrum ratio >1.35 is abnormal (sacroilitis)

-95% of fx detected by 3d (skull/spine/ pelvis fx can take longer) and 95% healed by 3yrs (resolved uptake)

-Non-union at 6mos (atrophic=no uptake so no potential of healing; reactive= persistent uptake)

-H.O. (initially “immature” has high uptake on all 3phases; later “mature” less uptake)

-Failed spinal fusion (focal uptake >1yr suggestive of pseudoarthrosis; mild diffuse uptake is normal)

-Bone graft viability (perform within 1 week of surgery; photopenia suggestive of non-viable graft)

-AVN  (photopenia up to 1moà donut 1-3mo (subacute)à diffuse increased à normalized)

-Cancers that rarely metastasize to bone include H&N, uterine, cervix, and colon CA

-Single rib met (10%); single vertebral met (>50%; esp lung/breast/prostate CA; T>Lspine); isolated sternal met (80% esp breastCA)

-Cold lesion=SBC, hemangioma, EG (variable uptake; 10% are cold; 30% of lesions not detected), lytic met, AVN/infarct, XRT (within 1mo of >40Gy and normalizes after >6mos), metal artifact

-Bone island, NOF may not have any uptake

-Mild uptake within enchondroma, exostosis, osteoma (active phase), NOF

-Hot b9 tumors=osteoid osteoma (3ph positive target sign), osteoblastoma (2phase pos), chondroblastoma  (variable), GCT, ABC (2 phase ring uptake), FD

-Superscan=mets, metabolic (“HOAH”= sec HPT, osteopetrosis, acromegaly, hypervitaminosis D, fluorosis), myeloproliferative d/o (myelofibrosis), mastocytosis, Paget’s

-Myositis ossificans can show up on BS before Xray by 6wks

-Prostate CA: perform BS for PSA>10, bone pain, high Gleason score (8-10), elevated serum alkaline phosphatase

 

BRAIN DEATH

Tc-HMPAO (ceretec) or TC-ECD (neurolite)

20-30mCi IV

● No patient prep

● Not affected by drug intoxication, hypothermia, or metabolic derangement

● Hyperventilation or high dose barbiturates may decrease brain flow

● Scintigraphy is for “confirmation” not “diagnosis” of brain death

 

● Study usually ordered by Neurology (deep unresponsive coma; absent spontaneous respiration; absent brain stem reflexes; abnl EEG)

● Consider scalp band placement (for adult patients without head trauma)

● Rapid IV bolus via ≥22G essential (don’t “blow the flow”) with NS flush

● Anterior flow (1s/fr) and anterior/lateral blood pool (5min statics) followed by 20min-2hr delayed SPECT imaging (no SPECT if using Tc-DTPA or other flow agents)—use head holder with shortest radius with LEHR collimator for optimal SPECT

● Zoom is important for peds

● Q.C.= distinct extra-cranial carotid activity to ensure fast tight bolus

● Normal=trident signs on anterior flow (MCA and ACA); cerebral sinuses on BP; normal cerebral/cerebellar uptake on SPECT

● Abnormal=absent arterial and venous activity (artifactual sagittal sinus activity may be retrograde via ECA or transverse sinus activity from jugular venous reflux); “hot nose”sign; no cerebral or cerebellar parenchymal activity

● Scalp hematoma or hyperemia related to skull fracture may mimic residual cerebral perfusion

 

● IMPRESSION:

-No scintigraphic evidence for brain perfusion or parenchymal uptake.

-In combination with abnormal neurological exam and EEG, scan is consistent with brain death.

-Severely decreased or markedly abnormal brain perfusion with some residual cerebral and/or cerebellar perfusionàrecommend repeat scintigraphy in 48hrs.

-Poor brain perfusion study due to suboptimal technique.

 

BRAIN SPECT

Tc-HMPAO (ceretec) or TC-ECD (neurolite)

20-30mCi IV

 

 

1g Diamox IV slow over 5min

(14mg/kg kids)

● No caffeine, alcohol, tobacco x24hr before exam

● Avoid CNS depressants

● Remove EEG Leads

● Indications for brain SPECT: stroke/TIA, seizure, tumor, brain death, dementia

● Indications for Diamox: Assessment of cerebral perfusion reserve in TIA; vascular anomalies (look for steal phenomenon); vascular dementia; vasospasm after SAH treatment; Moyamoya (to assess which hemisphere is more affected); assess need for carotid shunting during CEA

 

 

 

● ECD has higher cerebral extraction and slower clearance; also unlike HMPAO, no increased uptake with luxury perfusion but can have uptake in cerebral tumors

● Use stabilized HMPAO within 4hrs of constitution (unstabilized within 30min); 6hrs for ECD

● Start IV 15min before injection

● Ask patient to remain still and quiet 5min before, during, and 5min after injection

● After injection, place patient in dark/quiet room (ask to remain still and awake with eyes open with no speaking or reading) x60min (ECD) or 90min (HMPAO)

● Sedation should be performed at least 15min after injection and preferably just before imaging

● Use head holders (secure head and chin gently) and use shorter radius (15cm) along with LEHR collimator for higher resolution for SPECT (120stops with 20-40s/stop)

● Review imaging for motion artifact before letting patient go

● 128x128 matrix; Recon using BW filter order 10 and cutoff 0.5  

● Encourage voiding after scan to reduce exposure to bladder

 

INTERPRETATION:

● By 2yrs of age, cerebral brain perfusion pattern in kids is similar to adults

● With aging decreased frontal brain perfusion can be seen

● Cerebellum and occipital cortex have highest activity

● 10% difference in perfusion from contralateral cortex is significant; others say cortical activity <60% of max cerebellar activity is significant (esp if >1cm in size)

● More sensitive than CT for CVA in first 24-48hrs (not useful beyond 72hrs); defect usually larger than CT due to ischemic penumbra 

● SPECT correlates with stroke severity and can predict outcome:

1. Normal brain perfusion= minor stroke or restored perfusion or adequate collateral flow à no need for thrombolytics à good prognosis

2. Acutely decreased perfusion= moderate severity ischemia à thrombolytics indicated

3. Acutely absent perfusion à severe ischemia à use thrombolytics cautiously à poor outcome

● Luxury perfusion is seen with HMPAO (not ECD) in subacute phase (3d to 3wks) of CVA (uncoupling of flow and metabolism)

● Crossed cerebellar diaschisis can be seen with infarct, seizure, or tumor

● Uptake in tumor is variable (glioma have uptake if not low grade; mets usually don’t have uptake)

● Bilateral temporal lobe uptake in Herpes encephalitis

● AVM is photopenic (no cells)

 

DIAMOX CHALLENGE:

● Acetazolamide ACZ (vasodilator; carbonic anhydrase inhibitor; diuretic)

  1day protocol: 5mCi HMPAO/ECD for baseline/pre-diamox SPECT à wait 60min (ECD) or 90min (HMPAO) before imagingàthen inject Diamox 1g IV slow over 5minà wait 15-20min (avoid further delay) before injecting 20mCi HMPAO/ECD for post-diamox SPECTàwait 60min (ECD) or 90min (HMPAO) before imagingàhave patient void prior to scanning (diuretic effect)

● 2day protocol: day1=20mCi post-diamox brain SPECT; day2 (wait 24hrs) =20mCi baseline brain SPECT without Diamox

● Contraindications for Diamox: sulfa allergy; within 3d of acute stroke or intracranial bleed; relative contraindication if history of migraine (may provoke migraine); caution if renal/hepatic insufficiency; some say avoid in sickle cell disease

● Side effects: mild vertigo, tinnitus, perioral paresthesia, rare nausea, may provoke migraine, diuretic effect (have patient void prior to imaging)

● >10% decrease in perfusion compared to contralateral brain is significant

● Abnormal if <10% increase in regional CBF with diamox

● Matched baseline and post-Diamox = no significant ischemic penumbra or brain at risk

● Mismatch with post-diamox defect>pre-diamox=significant ischemic penumbra or brain at risk

 

SEIZURE:

-Tc-HMPAO preferred over Tc-ECD

-Partial (localized to part of brain) vs generalized (diffuse cortical)

-Simple partial (without loss of consciousness) vs complex partial (with loss of consciousness; usually temporal lobe)

-Types of generalized seizures include: absence, atonic (drop attacks), grand mal (tonic/clonic), myoclonic

-Grand mal (with convulsion like tonic/clonic) vs petit mal (no convulsion)

-SPECT: ictal and interictal with SISCOM (subtracted ictal SPECT co-registered to MRI=ictal minus interictal)

-For ictal scan: hold anti-epileptics; admit patient with continuous monitoring with scalp EEG and video (be on lookout for aura of complex partial seizure or patient’s typical seizure); inject radiotracer as rapid bolus within 20s (<30s) of seizure onset; prefer to have IV in both arms and to inject in clonic arm preferably when aura starts; record EEG for at least 5min after seizure or until baseline activity is resumed; may sedate prior to imaging; image within 4hrs (remove EEG electrodes prior to imaging)

-For interictal scan: keep on antiepileptic meds; monitor scalp EEG 2hrs before and 15min after injection to make sure patient is seizure free

-Hyperperfusion on ictal and corresponding hypoperfusion on interictal SPECT is diagnostic

-For TLE, initially see temporal lobe hyperperfusion à followed by post-ictal medial temporal lobe hyperperfusion and lateral temporal lobe hypoperfusion (can also see ipsi BG hyperperfusion)

-Interictal FDG PET better than interictal SPECT due to more pronounced hypometabolism than hypoperfusion

-Contralateral cerebellar diaschisis can be helpful

-Higher sensitivity for localizing temporal TLE (70-90%) vs extra-temporal epilepsy (66%)

-Extratemporal seizure focus harder to localize (brief activation but rapid propagation); may have subcortical activation in 80% (i.e. ipsi BG hyperperfusion)

-PET: regional hypometabolism is useful for lateralizing seizure focus (but less reliable for localizing focus); difference of 15% btwn suspected focus and contralateral brain on PET is significant; may see ipsi thalamic hypometabolism; cerebellar diaschisis is mainly seen with frontal/parietal focus; bilateral temporal hypometabolism predicts poor outcome after surgery; bilateral cerebellar hypometabolism is seen with chronic anti-epileptic therapy; focal subcortical heterotopia can have decreased/normal/increased uptake in kids

 

TUMOR (THALLIUM):

-Thallium: 5mCi IV and image after 2-3hr

-Does not cross BBB so no normal brain activity

-Useful to distinguish btwn lymphoma (thallium and gallium pos) vs toxo (thallium neg and gallium pos); some start with thallium which if equivocal give anti-toxo meds x 7-10d and do PET/CT which has better accuracy for lymphoma (and is usually neg for toxo)

-Also, good for tumor recurrence vs XRT necrosis; some do dual-isotope Tl-201 and Tc-HMPAO for tumor vs XRT (if equivocal thallium, look for preserved or increased perfusion suggesting tumor)

-Tumor: normal brain ratio >2.5 is significant

-Can detect tumor >2cm

-Steroids may decrease uptake

 

BSGI

Tc-sestamibi (Miraluma) 20-25mCi IV (contralateral to site of interest)

● Schedule btwn day 2 to 12 of menstural cycle if possible

● If lactating, postpone for 3mos after cessation of lactation

● Contraindicated in pregnancy

● Ideally performed prior to biopsy/surgery

● Perform within <2wks of FNA or cyst aspiration (to avoid false pos)

● Wait >3-4wks after core or excisional bx  (to avoid false pos)

or could do w/in <72hrs after any needle procedure

● Can see uptake at lumpectomy site up to 1year

 

● Inject contralateral upper extremity (or else foot injection) and avoid extravasation

● Followed by 10cc NS flush (remove IV, raise arm overhead and squeeze ball x 1min)

● Seated for scanning (DILON and DIGIRAD immobilize breast without sig compression; 2-3lbs of compression)—may have patient stand if big belly

● Begin imaging 5-10min after administration (good until 2hrs)

● Planar 10min or 175K (7min minimum); +/-10% around 140keV

● Bilateral CC (detector inferior to breast) and MLO (detector inferolateral oblique to breast)

● If needed, additional views may be acquired (like XCC, LM or ML, implant displacement, cleavage)

● Also image injection site to exclude infiltration

● Gray scale or Color linear monochromatic (eg cool or hot metal) preferred over multi-color (eg rainbow) for viewing

● Consider masking any focal hi-activity to aid in identification of nearby lower activity lesion

 

INTERPRETATION:

-Homogeneous uptake of the radio-pharmaceutical in the breast or axilla is consistent with a normal study. (BIRADS 1)

-Patchy or diffusely increased radiopharmaceutical uptake in the breasts is usually a normal variant, especially when the distribution correlates with mammographic anatomy. (BIRADS 2)

-Features suggestive of benign disease of the breast are diffuse or patchy uptake of mild to moderate intensity, often bi-lateral, with ill-defined boundaries.

-Multiple patchy areas of uptake, mild to moderate intensity. (BIRADS 3)

-Low-intensity focal areas of increased radiopharmaceutical uptake in the breast or axilla (in the absence of radiopharmaceutical infiltration): equivocal result, with ddx of malignancy, inflammation, atypia, fat necrosis (including complex fibroadenoma, adenolipoma, papilloma, abscess, sclerosis adenosis, radial scar,   etc). (BIRADS 4)

-Intensity of focal uptake in malignant lesions is highly variable. Mod to high intensity focal uptake with well-delineated contours is consistent with malignancy. (BIRADS 5)

-Focal increased uptake (1 or more foci) in the ipsilateral axilla, in the presence of a primary lesion is strongly suggestive of axillary lymph node metastatic involvement (in the absence of radiopharmaceutical infiltration)

-Masking of high-activity lesions in the breast can improve visualization of adjacent breast tissues. Masking can be performed by placing appropriately sized pieces of lead between the lesion and the detector. Both the masked and original images should be included in the final display

-Don’t ignore lesion seen only on one view (usually happens with CC view)

-S/S=95%/89%;  sensitivity≥90% for DCIS and ILC; can detect lesions as small as 4-5mm

-NPV is 96-98% (lower for axillary imaging)

-Compared to MRI, BSGI has lower sensitivity but higher specificity

 

CISTERNOGRAM

In-DTPA

0.5-1.0mCi intrathecal (use higher dose 1-3mCi for leak study) in small volume ~1-2cc

CSF leak or NPH

-Determine site of CSF leak (rhinorrhea/otorrhea etc)

-Coordinate with clinician or IR doc for LP access (patient will be screened by them)

-For CSF leak, coordinate with surgeon for pledget placement (buccal mucosa as control) and removal (usually after 4-6hr)

-Need opening pressure at time of LP for NPH (>25cmH2O is elevated)

-Bedrest after injection ~3hr (to avoid spinal headaches)

 

VP shunt

-Coordinate with Neurosurgery for shunt access and injection into reservoir

 

 

● MEGP collimator

 

CSF leak

-Labs: beta-2-microglobulin

-Use 1-3mCi (higher dose) In-DTPA intrathecal

-Wait 2hrs before placement of 1cm square pledgets (with string for retrieval; mark string with site name) by ENT physician (one under tongue or buccal mucosa as control)

-Obtain 5cc blood in heparinized tube at time of placement à centrifuge to remove 0.5cc plasma à measure in well counter

-Remove pledgets 4hrs after placement (or 6hrs after injection)

-Obtain another 5cc blood in heparinized tube at time of removal à centrifuge to remove 0.5cc plasma à measure in well counter

-Count pledgets (for same amount of time as blood) individually in labeled vial using well counter (some put 0.5cc NS in vial)

-Pledget to average plasma counts ratio of >1.5 is positive (<1.3 is normal)

-Early and delayed static imaging (at 2, 4, and 6hr) of skull or spine in ant/post and lateral projections with patient positioning to aid in leak detection

-Early 2hr imaging over spine is useful to ensure success of injection

-SIH (spontaneous intracranial hypotension): image frequently (q5-10min posterior statics during first hour followed by q15min image during next 2 hours and 24hr delayed over brain); look for spinal leak, early visualization of urinary bladder (1-3hr), and lack of activity over convexities at 24hr; early bladder activity can be false positive in case of traumatic injection

-Early visualization of systemic radiotracer (within kidneys or bladder) is abnl (no appreciable radiotracer in blood samples at 4hr)

 

NPH

-Measure opening pressure prior to inj

-Imaging over spine at 2hrs to ensure successful injection and to exclude spinal leak

-4hr, 24hr, and 48hr anterior and lateral imaging of brain

-@2-4hr=basal cisterns (“neptune’s trident” on frontal view; minimal ventricular penetration may be normal)

-@12-24hr=over convexities (abnormal ventricular stasis seen as “heart-shaped” vents on frontal view; ok to have faint ventricular activity in elderly)

-@48hr=clearing of activity

-NPH=treatable dementia, hydrocephalus with normal CSF pressure, incontinence, ataxia

-Communicating hydrocephalus (abnl CSF resorption)= prior subarchnoid hemorrhage, meningitis, leptomeningeal carcinomatosis ßoverall findings similar to NPH but generally no reflux into ventricles

-Grading (Type I-IV):

I= normal migration of CSF without reflux

II= Delayed migration without reflux

III= Delayed clearance and transient reflux

a) clears via convexities

b) clears via alternative pathways like trans-ependymal flow

IV= Poor clearance and persistent reflux (VP shunting indicated)

-Note: delayed clearance without reflux suggests communicating hydrocephalus

 

VP shunt

-Get Xray to look for obvious kinked/disconnected tubing

-Sterile access to reservoir by Neurosurgery (may measure opening pressure with manometer during access)

-Supine dynamic (1min/fr) and static imaging (from head to pelvis)

-Initial manual pressure on distal limb (at jct of reservoir and distal limb) at time of injection to allow radiotracer reflux into ventriclesàafter adequate filling of ventricles, release pressure to allow distal limb to fill (normal or high opening pressure in reservoir suggests patent proximal limb)

-Activity should rapidly clear from ventricles <15-30min

-May need to pump reservoir to remove excess activity from reservoir

-Transit from reservoir to distal limb ≤10min

-Activity should freely disperse into peritoneal cavity without localized CSFoma or pseudocyst

-1hr and 2hr delayed imaging over abdomen/pelvis (up to 24hr if needed)

 

DACRYO-SCINTIGRAPHY

Tc-pertech.

100uCi (in 0.1cc volume sterile NS) per eye

● No eye makeup

● No contact lens

● Indication: epiphora (excess or overflow of tear which can be related to mechanical obstruction)

 

● Use micro-pipette or eye dropper or 1cc tuberculin syringe to administer 100uCi (in 0.1cc) per eye

● With patient in sitting position with head tilted back, place drops laterally  (place 4cc gauze on cheek to catch any runoff)

● Image using pinhole collimator if possible or use zoom

● Take 1min anterior static image q5min for 30min

● Blinking and deep nasal breathing can assist in tracer drainage

● Have patient flush eyes with water after exam is over (avoid wearing contacts lens for few hours)

 

INTERPRETATION:

● Nasolacrimal sac should be visualized within 1 min and nasolacrimal duct within 2-3min

● Lack of drainage into nasal cavity within 15min indicates blockage of drainage system

● ANATOMY: Lacrimal canaliculi (sup/inf)à common canaliculus à lacrimal sac à nasolacrimal duct à nasal cavity (via duct orifice in inferior meatus)

● Classification of obstruction:

-Pre-sac (class III)

-Pre-duct (class II)

-Intra-duct (class I)

 

DaT SCAN

I-123 FP-CIT Ioflupane

3-5mCi IV slow over 20s

 

● SSKI 100mg PO (0.1cc of 1g/ml in cup of water) 1hr prior to injection for thyroid blockade (alternative 400mg Potassium Perchlorate)

Hold following meds (5 half lives):

-Mazindol (Mazanor, Sanorex) 3d

-Phentermine (appetite suppressants) 14d

-Modafinil 3d

-Bupropion/Amfebutamine (Welbutrin, Zyban, Voxra, Aplenzia) 8d

-Benzatropine (Cogentin) 5d

-Fentanyl 5d

-Cocaine 2d

-Amphetamines 7d

-Methylampehatmine 3d

-Methylphenedrate 2d

-Dexamphetamine 7d

● Ask about claustrophobia

 

 

● Need 2d notice for ordering dose (usually not available on Mondays)

● Calibration factor needs to established for liquid I-123 for vial and 5cc syringe

● Start IV and use a 3-way stop to flush injection syringe with NS

● Wait 3-6hrs before imaging

● Use head holder and secure head/chin with coban (pull shoulders down)

● Avoid lateral head tilt

● Use shortest rotation radius 11-15cm (make sure SPECT camera clears the shoulders)

● 128x128 matrix; 30s/stops x60stops with LEHR collimator

● FBP: BW order=8 cutoff=0.6

● IR: subsets=4 iterations=8 with Gaussian=8

● For image processing, orient the midsagittal slice such that inferior aspect of frontal lobe along same horizontal line as inferior aspect of occipital lobe

 

INDICATIONS:

● Differentiate Parkinson’s disease vs Essential tremor (or Psychogenic or drug induced aka neuroleptic-induced)

● Early diagnosis of PD

● Differentiate btwn Alzheimer’s vs DLB

 

INTERPETATION:

-I-123 FP-CIT imaging evaluates integrity of nigrostriatal dopaminergic synapses by visualizing presynaptic dopamine transporters (DaTs)

-Use grayscale or cool/warm metal LUT

-QC images on coronal for lateral head tilt

­-Interpretation is made using axial images

-Normal scan= “comma” shaped uptake

-Posterior putamen is affected initially and usually on the side contralateral to neurologic signs

-May quantify using ipsilateral cerebellum/occipital lobe as reference (semiquantitative)

-SBR (striatal binding ratio) =  (mean counts in striatum – mean counts in occipital) / (mean counts in occipital)

-Performs this on 3 contiguous slices (get average of mean counts)

-Compare SBR for L to R striatum (no normal values cutoff)

-Normal uptake: caudate > putamen by 10-20% (looks like “comma”)

-Abnormal decreased post then ant putamen uptake (looks like “period”)

-Decreased uptake may be asymmetric (striatum contralateral to affected side is usually abnl)

-Conditions associated with loss of dopaminergic neurons: PD, PSP, CBD, MSA, DLB

 

IMPRESSION:

-Normal (slight heterogeneity of putamen ok)

-Abnormal but not indicative of typical nigrostriatal degeneration (or presynaptic striatal dopaminergic deficit) associated with Parkinsonian Syndrome (DDX: consider ET, drug-induced or vascular parkinsonism, psychogenic parkinsonism, Alz disease, dystonic tremor, or normal patient)

-Consistent with nigrostriatal degeneration (or presynaptic striatal dopaminergic deficit) typical of Parkinsonian Syndrome (PD, MSA, PSP, CBD, or Lewy body dementia)

 

Note: Sensitivity 78%, Specificity 97%

 

DEXA

N/A

● No oral/rectal contrast or NM exam 1week before

● Avoid calcium supplements 24hrs before exam

● Need patient’s height and weight

 

 

● Osteoporosis=decreased bone mass

● Osteomalacia=decreased bone mineralization

 

RISK FACTORS:

-Estrogen deficiency (early menopause<45yo, hypogonadism, etc)ßLupron therapy require annual screening

-Systemic steroid tx (at least 3mos of 5mg/d prednisolone or equivalent)

-Low BMI (<19)

-Disorders like untreated hyperthyroidism, primary HPT, chronic renal dz, Cushings (cortisol), chronic malnutrition, malabsorption syndrome, osteogenesis imperfecta etc

-Personal history of fragility fx after age 40 (spine/hip/wrist)

-Maternal family history of hip fx

-Others: RA, smoking, excess alcohol ( 3 or more units daily) etc

 

INDICATIONS:

-Women ≥65 and Men ≥70

-Women <65 and Men <70 if they have risk factors listed above

-Anyone being considered for therapy

-Therapy monitoring

-Fragility fracture seen on imaging

 

TECHNIQUE:

-3 vendors: Hologic, GE (Lunar), Norland

-Xrays of 2 different energies (Low=70-100kev and High=140kev) à different attenuation of ST and bone

-Axial (central) DEXA

   -PA spine=”L1-L4” with hip/knee flexed

   -Both Hips=”total femur” (combo of

    neck/troch/inter) and “femoral neck” 

    with hip in 15-25deg internal rotation

    and slightly abducted

-Appendicular (peripheral) DEXA

   -Non-dominant forearm in pronation

   -“ultradistal radius”=cancellous bone

    & “33% radius” diaphysis=cortical bone

-Forearm DEXA is performed if: primary HPT (cortical bone affected more than cancellous bone); can’t have hip or spine due to hardware; weight exceeds table limit

-In children 5-19yo, can do AP spine; TBLH=total body less head BMC and areal BMD (hip not reliable due to variability in skeletal development and lack of reproducible ROI)

-Make sure individual vertebral BMD within 1.0 T-score of adjacent (can exclude outlier but need at least 2 vertebra for measurements) and femoral neck/troch/inter BMD within 1SD of total hip 

-Bone mineral density (BMD in g/cm2) = (Bone mineral content BMC g) / (Area  cm2)

-Report BMD in 3 decimal places

-Spine BMD shows earliest changes in BMD for pts<65yo; spine BMD is quite reproducible and best for f/u

-Calculate T-score or Z-score = (pt BMD – ref BMD) / 1SD

-Precision error=calculated with 30 patients evaluated twice (or 15 patients evaluated thrice) with results from different techs averaged to calculate Root Mean Square (RMS) SD

-Least significant change (LSC) is 2.77 times site-specific precision error (RMS SD)

-Statistically significant change (%change/yr allows comparison to prior DEXA) is change in BMD that equals or exceeds LSC (with 95% confidence)

-Assuming a precision of 1%, a 2.8% change in BMD is usually considered sig

-Follow-up 1year after starting or changing therapy

-For follow-up compare BMDs (not T-scores)

-Monitoring change in spine BMD is preferred (best precision and most responsive to therapy); second best is total hip (forearm does not respond well to therapy)

-Dose 0.01mSv (spine and hip)

 

REFERENCE DATABASE:
-Gender-specific database used by all vendors for T-scores

-Ethnicity-specific database used by all vendors for Z-scores

-Vendor-specific T-score database for spine

-All vendors use NHANES-III database (20-29yo Caucasian females) for hip T-scores (used for all ethnic gps)

-Vendor-specific normative database for peds

 

INTREPRETATION:

-T-score (postmenopausal women and men ≥50yo; Number of SD from mean of normal gender-matched young 20-35yo Caucasian population):  

     -Normal ≥-1.0

     -Osteopenia(low bone mass)-1.1 to -2.4

     -Osteoporosis ≤-2.5

-Any BMD + personal history of fragility fracture = osteoporosis

-Z-score (premenopausal women, and men<50yo; Number of SD from mean of age/gender/race-matched peers):

      -Normal>-2.0 (BMD “approp for age”)

      -“Below the expected range for age”

      (adults) or “Low bone density for

       chronologic age” (children) ≤-2.0

      -Consider secondary causes of low

       BMD

-For children (5-19yo) prefer age/gender-matched and height-adjusted Z-score (may need to be further adjusted for pubertal Tanner stage and skeletal maturation)

-FRAX (fracture risk assessment tool for 40-90yo based on gender and race): uses femoral neck BMD to calculate 10-year probability of hip fx (cutoff 3%) and major osteoporotic fx (cutoff 20%) in osteopenic postmenopausal women and men ≥50 who are untreated and no history of fragility fx

 

GENERAL TREATMENT RECOMMENDATION:

-For all patients, consider calcium 1200mg/d and vitD 1000IU/d

-Treat with Alendronate/Fosamax 70mg qweek (Risedronate/Actonel 35mg qweek if Alendronate not tolerated or contraindicated)

-Others: bisphosphonates (Boniva, Reclast), Selective Estrogen Receptor Modulator (Evista), Recombinant PTH (Forteo), Human Monoclonal Ab (Denosumab/Prolia)

-Consider Endocrine consult if Z-score -2.0 or if fragility fracture occurs while on treatment or decreasing bone density while on therapy or young patient with fragility fracture

-Lab workup for secondary causes: SPEP; TSH; AM testosterone (men); ALT; creatinine; albumin; alkaline phosphatase; vitamin D 25-hydroxy; 24hr urine for calcium/creatinine; parathyroid hormone; serum calcium

-Counsel: stop smoking, reduce alcohol intake, do exercise, fall prevention tips

 

ONLINE CALCULATORS:

-FRAX calculator: http://www.sheffield.ac.uk/FRAX/index.jsp

-PEDS calculator (Baylor):

https://www.bcm.edu/bodycomplab/Flashapps/AllDXArefsChartpage.html

-PEDS BMDC study (≤3rd percentile is abnormal): “The Bone Mineral Density in Childhood Study” JCEM 2007 (age 5-23yo; black/non-black; height adjusted z-score and percentile; for Hologic)

-Calculator to compare DEXA from different DEXA vendors:

https://courses.washington.edu/bonephys/opBMDs.html

 

VFA (vertebral fracture assessment):

-Lateral spine (T- and L-spine) to detect compression fx

-Genant visual semi-quant method for diagnosing fx (wedge/biconcave/crush fracture; Normal Grade0=no fracture, Mild GradeI=20-25%, Moderate GradeII=26-40%, and Severe GradeIII>40%)

-Morphometric measurement (for severity of deformity) alone is unreliable

-Consider VFA if osteopenic and female>70yo or male>80yo, height loss 4cm women or 6cm men or self-reported vertebral fracture

TBS (trabecular bone score):

-Used in assoc with FRAX and BMD to adjust probability of fx in postmenopausal women and men≥50yo

 

HAL (hip axis length):

-Used as FRAX- and BMD-independent risk factor for hip fx in women

 

Body composition:

-Measures fat and lean mass

-Indications: HIV with risk of lipoatrophy on antiviral tx; obese pts undergoing bariatric surgery; pts with muscle weakness or poor physical conditioning

 

DMSA SCAN

Tc-DMSA

0.05mCi/kg IV (min 0.5mCi)

● No patient prep

 

 

● Wait 2-4hrs after injection (40% bound to –SH group of PCT)

● Static imaging in ant/post and oblique projections followed by SPECT

● Consider magnification or pinhole imaging esp for babies

● Left upper pole may appear photopenic on planar due to overlying spleen

● Findings:

-Solitary/multiple/diffuse peripheral wedge cortical defects

-Diffuse decreased unilateral renal uptake

-Asymmetrical renal size (diffuse pyelo vs chronic reflux nephropathy)

● Anatomic variants:

-column of bertin (has normal uptake)

-dromedary hump

-junctional cortical defect

-fetal lobulations

● False positive:

-renal cyst/mass

-obstruction

● Consider 3mos f/u to assess pyelo vs scar

 

ESO TRANSIT & GERD

Tc-SC/DTPA 0.5mCi PO in water or O.J.

● NPO x4hrs

ESO TRANSIT:

● 10cc water

● Supine with straw and instruct to drink, hold, and on command perform single swallowà after 1min have patient do dry swallows q30-60s for next 9min (at least 5 dry swallows)

● Dynamic posterior imaging 1s/fr x1min followed by 10s/fr x9min (total 10min)àif persistent activity in eso at end of exam do upright imaging for another 5min (1min/fr) with occasional dry swallows

● Draw equal ROI on upper, mid, and lower third of esophagus

● Normal eso bolus transit time (i.e. time till <10% of max activity remaining) is 15s (90% emptying)

● Also report % retention at end of 10min (some say <18%)—useful to assess for scleroderma (>30% retention and improves with upright position) vs achalasia (>50% retention and no improvement with upright position)

 

GERD:

  120cc (4oz) or 240 (8oz) orange juice PO or via G-tube

● Drink upright and wait 30sec and then supine (do all supine if given via G-tube)

● Dynamic posterior imaging 10s/fr x1hr with intermittent Valsalva maneuver (if available consider abdominal binder for adults but not for kids)

● Document number of reflux events, duration (<10s or >10s), and proximal extent of reflux (below or above mid eso)

● Some say >4% reflux is abnl (<3% is normal)

 

FIRST PASS RNA

20-30mCi

Tc-DTPA or Tc-pertech. or Tc-RBC IV (prefer in small volume ~1-2cc)

● Avoid caffeine 2hr before exam

● Test may be combined with MUGA

 

● Start ≥20G IV in right AC fossa (don’t use central line)

● Rapid IV bolus <2sec is essential (use 3 way stop with 10-20cc NS flush)

● Rapid frame mode 0.04s/frame or 40ms/frame for 1500 frames (60sec imaging time)

● 30deg RAO projection preferred for RVEF; Anterior view for LàR shunt

● Gating not necessary

● ROI over SVC to Q.C. for adequacy of bolus (FWHM <4s )

● ROI over lungs to assess for pulmonary re-circulation (dual peaks with second peak proportional to shunt) seen with L to R shunt (gamma variate analysis)

● Shunt ratio=A1/(A1-A2); Normal Qp:Qs ratio <1.2 (>2 may need surgical correction)

● Use lung ROI for background correction rather than periventricular ROI

● Normal RVEF 40-60% (use 3-5 beats averaged summed peaks with >70-80% of max activity)

● RVEF usually 5-10% less than LVEF

 

GASTRIC EMPTYING

SOLID

Tc-SC

0.2-0.4mCi

PO

● NPO at least 4-6hrs

● Hold x2days b/f exam

-Laxatives

-Opiates (Codeine/Morphine etc)

-Tranquilizers (Valium/Ativan etc)

-Anti-nausea and prokinetics (Reglan/Zelnorm/Motilium/ erythromycin etc)

-Anti-spasmodic (Bentyl/Donatal/ Levsin/Robinul)

-Zofran (odansteron) does not affect GE

● Hold insulin and oral diabetic medication until after exam (only take ½ dose of insulin in AM if absolutely needed)—prefer BG<275 before exam

● No smoking or alcohol on day of exam

 

 

● Record percentage of meal consumed

● For patient on tube feeds: prior to study hold TPN and tube feeds x4-6hrs; figure out what they normally get per hour (eg 30cc/hr) and then give 2hr worth (eg 60cc) of feed as a bolus (30cc labeled feed followed by 30cc unlabeled feed flush)

 

4hr standardized solid egg meal (prefer)

-4oz egg beaters or egg whites or 2 large eggs (cooked in microwave or skillet) with 2slices of white bread (can be toasted), 30g jam/jelly packet (two packets with 14g per packet), and 120cc (4oz) water for total of 255kcal meal (24%protein, 2%fat, 72%carbs, 2%fiber)

-Allow 10min to finish meal

-Initial, 1hr, 2hr, and 4hr ant/post static imaging with GM

-% Gastric retention = (Gastric counts GM) / (Total counts GM x DF)

-Decay factors (DF) for Tc at 1hr is 0.891, 2hr is 0.794, and 4hr is 0.631

-If 2hr gastric retention <30% or >65%, can skip 4hr imaging

-Normal % gastric retention: 1hr=30-90% (<30% consider rapid emptying); 2hr≤60%; 4hr<10%

-Mild delayed 11-20% retention at 4hr; moderate 21-35%; severe 36-50%

-Bonta criteria: at 2hrs, retention >65% is abnormal and <45% is normal; otherwise proceed with 4hr delayed imaging

-No established 4hr normal values for peds

-Hyperglycemia and tobacco can delay emptying

 

4hr non-egg meal options

-For those unable/unwilling to eat eggs or allergic to eggs, may substitute with 4oz Ensure/Boost plus (similar kcal as solid egg meal but generally higher in protein content and lower in carb content)àNormal <50% retention at 2hr and <10% retention at 4hr

-Ensure “original” has 220kcal; Ensure “plus” has 350kcal; Boost “original” has 240kcal; Boost “plus” has 360kcal; Boost “glucose control” has 190kcal

-For Gastric bypass: consider Ensure/Boost plusàmay consider 1hr dynamic along with usual static views

 

90min dynamic solid GE (older protocol; not preferred)

-Anterior and posterior views (with geometric mean) vs LAO 

-Normal T1/2 is 45-90min for dynamic solid GE (using linear fit)—i.e. 50% emptying by 90min

-Rapid emptying as <30% retention at 1hr

-See prolonged lag phase and slow post-lag emptying in diabetic gastroparesis

 

 

90min semi-solid meal (oatmeal)

-Alternative for those who can’t have solid egg meal and have uncontrolled DM (cant receive Ensure)

-1oz “instant” oatmeal in 100cc (3.3oz which is half of a small carton of milk containing 8oz) warm whole milk with 1packet of sugar for total of 178kcal

-Dynamic imaging x90min

-Normal T½ is ≤50min (using linear fit) 

 

Small Bowel Transit

-Perform on dual-head camera

-Can combine it with solid GE study

-1.0mCi Tc-SC in standard solid egg meal + 0.2mCi In-DTPA in 300cc water

-Use MEGP collimator

-Setup for dual isotope imaging (15% around 140keV and 15% around 172 and 247keV)

-Do dual-isotope static supine imaging x1min in ant and post projection over entire abd/pelv at 0hr, 30min, 1hr, 2hr, and 4hr

-Do single isotope (In-111 only) static imaging x1min in ant and post projection over entire abd/pelv at 6hr

-Calculate geometric mean

-SB transit=% of total indium counts passed into terminal ileum + cecum at 6hr

-Normal >40% of activity in TI/cecum/asc colon at 6hrs

-Cecal arrival time=10% activity into cecum (normal 231 +/- 37min)

-There can be stasis within terminal ileum reservoir that’s why we don’t differentiate btwn terminal ileum and cecum

-Consider obtaining 24hr imaging (4min static and correct for decay) to determine location of cecum

-Disqualifier is >50% liquid gastric retention at 2hrs (non-diagnostic SB transit study)

-Delayed SB transit can be secondary to abnormal colonic transit

 

 

GASTRIC EMPTYING LIQUID

Tc-SC/DTPA

0.2-0.4mCi PO in water

 

 

 

 

 

 

In-DTPA

0.2mCi

(if simultaneous with solid)

 

● Same prep as solid G.E. above

● 300cc (10oz) water (200cc labeled followed by 100cc unlabeled) administer semi-upright position

● May modify to 120cc water (60cc labeled water followed by 60cc unlabeled water) if need to give via NGT for inpatient

● Dynamic LAO supine imaging x30-60min (1min/fr)

● Normal T½ is <23min for water (using exponential fit) 

 

Dual isotope liquid and solid GE

-Sequential dual-isotope imaging (not simultaneous)

-Do liquid GE first with 0.2mCi In-DTPA labeled 120cc water (dynamic LAO supine imaging x30min) using MEGP collimator

-Then do 4hr solid GE with 2mCi (not 0.2mCi) Tc-SC labeled standard solid meal (static LAO imaging at 0hr, 1hr, 2hr, and 4hr)—keep MEGP collimator on (don’t use LEAP collimator)

-Not unusual to have normal solid and abnl liquid GE

 

GI BLEED

Tc-RBC

15-30mCi IV (ultratag)

 

Alternative:

Tc-SC

10mCi IV

 

● Ask if patient has active lower GI bleeding (bright red blood per rectum)

● Make sure IR is on standby

 

 

 

● 3cc blood for in-vitro labeling (Ultratag)

● 3cc blood + ADC/heparin à Sn2+ PYP (reducing agent Tc+7àTc+4) à Na hypochlorite (oxidizes extracellular Sn) à Na citrate/ dextrose (sequesters Sn) àTc7+ pertechnetate à 20min incubation

● Labeling of beta chain of Hgb

● Dynamic anterior imaging x90min (flow 1s/fr x 1min and 1min/fr  x89min)

● Lateral static view may be helpful to differentiate bladder vs rectal activity

● If gastric activity, image over neck to rule out free or unlabeled Tc (look for thyroid activity)

● Optional delayed imaging up to 12-24hrs (consider 1mCi Tc-RBC re-injection if >12hrs OR consider Tc-SC 10mCi IV instead)

● NM detects bleeding at rate of 0.1cc/min while angio detects 1cc/min

● LGI bleed ddx: diverticulosis, angiodysplasia, CA, IBD

● UGI bleed ddx: gastritis, gastroduodenal ulcer, CA, free Tc (image over neck for thyroid activity)

● False pos=varices, aneurysm, vascular graft, penile activity (tape penis out of way), vascular neoplasm, ectopic kidney, uterus (menstural bleed), hemangioma, accessory spleen, free Tc (mimics gastric bleed), intraperitoneal hematoma

 

 

● Alternative to Tc-RBC: Tc-SC 10mCi IV with 30min dynamic imaging (may repeat as necessary with additional dose)

 

HEMANGIOMA

Tc-RBC

20-30mCi IV

(ultratag)

● No patient prep

● Prefer lesion size >1.5 cm

● Dynamic Flow (ant/post) and static Blood Pool (multiple projections) along with 2-3hr delayed SPECT (SPECT/CT is preferred)

● Typical hemangioma is cold early, warm on BP, and hot on delayed (equal in intensity to BP activity in heart or spleen)

● Lesion >1.5 seen on SPECT reliably (lesion ≥3cm seen on planar)

● Giant hemangiomas >4cm may appear heterogeneous (central scar)

● Hypervascular mass like HCC has increased flow (activity appears same time as aorta and spleen) but decreased BP and delayed activity (due to washout)

● Flow phase can help differentiate hemangiomas from hypervascular masses

● Hemangiomas are uncommon in cirrhotic liver

 

HEPATOBILIARY

(HIDA)

 

Tc-Choletec/ Mebrofenin

5-10mCi IV

(use higher dose for elevated TB)

 

 

 

CCK(sincalide) 0.02ug/kg IV slow (30min infusion for GBEF); mix 5cc sterile water in 5ug vial to get 1ug/cc conc

 

MSO4 0.04mg/kg IV (~4mg adults)

● NPO for at least 4hr (but less than 24hr)

● No opiates (like morphine, codeine etc) for at least 2hr

● Elevated TB or conjugated bili suggestive of biliary obstruction

 

For inpatients:

-If NPO >24hr or on TPN, give 0.02ug/kg CCK IV (slow over 5min) 30min before radiotracer injection to decompress distended GB (to avoid false positive)

 

For neonatal biliary atresia:

-Phenobarbital 5mg/kg/d PO (in 2 divided doses) for 5 days prior to exam to activate cytochrome P450 (confirm serum levels >15ug/ml)

-Arrange for sedation

 

● If NPO for more than 24hr, pre-treat with CCK 30min before injection

● Avoid CCK if recent opiates within 2-4hrs

● TB >20 may be prohibitive

● Higher hepatic uptake and less renal excretion of Choletec than Hepatolite

● Active uptake into hepatocyte and passive excretion into biliary system (without conjugation)

 

NORMAL SCAN

-Hepatic flow visualization 6-8s after renal or spleen

-No blood pool beyond 10min

-Peak hepatic activity by 8-12min

-≤2/3 of hepatic activity remains by 1hr

-Biliary activity usually seen by 20min

-≤1/2 of biliary activity remains by 1hr

-GB and SB activity by 1hr

-Delayed biliary-to-bowel activity can be normal (15%) or physiologic due to recent opiates or pre-treatment with CCK or suggestive of chronic cholecystitis

-GBEF >35% after 30min CCK infusion (GBEF >38% after 60min CCK infusion)

 

ACUTE CHOLECYSTITIS

-If no gallbladder activity during initial imaging, do 4hr delayed imaging (consider 4mg Morphine IV instead if see small bowel activity; no allergy to Morphine; not driving x4hr)

-Consider additional 1mCi IV booster dose prior to MSO4 or 4hr delayed imaging especially if significant hepatic washout at end of 60min (to improve detection of GB)

-Rim sign has high (~40%) association with complicated acute cholecystitis (gangrenous/phlegmonous)

-Cystic duct sign (nubbin sign) of acute cystic duct obstruction

-S/S is >95%/94%, NPV 99%, PPV 92%

Accuracy 95%

 

ACUTE “ACALCULOUS” CHOLECYSTITIS

-Usually sick inpatients

- Give CCK 30min (slow IV over 5min) before radiotracer to decompress the distended GB à if GB doesn’t fill in 4hrs (positive study) but if GB does fill à give CCK infusion over 30-60min to assess GBEF à  low GBEF is positive while normal GBEF is negative

-Optional: confirmation with In-WBC imaging at 4hr post-inj or Tc-HMPAO-WBC imaging at 2hr post-inj (SPECT helpful)

-Sensitivity 60-90%

 

CHRONIC CHOLECYSTITIS

-Delayed visualization of GB (>1hr but <4hr)

-Delayed biliary-to-bowel activity >1hr is a non-specific (can be normal in 15%)

-Delayed GB visualization or GB visualization after Morphine is suggestive of CC

-Depressed GBEF is most specific for CC

-After visualization of GB and bowel activity, perform GBEF using 0.02ug/kg CCK IV infusion over 30min in LAO projection

-GBEF = (GBmax – GBmin) / (GBmax –background) x 100

-GBEF>35% at 30min is normal (For 60min CCK infusion, normal GBEF is ≥38%)

-Ensure plus (8oz) PO is an alternative to CCK in non-diabetics (GBEF>33% at 60min is normal)

-Whole milk (250cc; 1carton is 8oz or 236cc) is an alternative to CCK in diabetic (GBEF≥44% at 60min is normal)

-Document any symptoms during CCK infusion (predictive of improvement after cholecystectomy)

-S/S 72%/82%

-Functional GB disorder (FGBD): chronic “acalculous” cholecystitis in outpt (GB dyskinesia); low GBEF in setting of normal ultrasound without gallstone

 

BILE LEAK

-Ask if patient has an internal/external biliary drain (which will need to be temporarily clamped)

-At end of exam, obtain static image of any percutaneous drainage bag or JP bulb

-If no obvious leak, consider 2-4hr and 24hr delayed posterior image of abdomen/pelvis and right lateral decub view (for slow leak)

-Look for biloma within GB fossa; re-appearing liver sign (subdiaphragmatic)

 

HEPATIC DYSFUNCTION OR BILIARY OBSTRUCTION

-Persistent hepatogram + residual BP activity=hepatocellular dysfunction

-Persistent hepatogram + no residual BP activity= hepatocellular dysfunction vs high-grade biliary obstruction (elevated TB and direct/conjugated bili suggestive of biliary obstruction)

-If no biliary or small bowel activity, consider 4hr and 24hr delayed imaging

-Don’t give CCK or Morphine

 

BILIARY ATRESIA

-Check serum Phenobarbital levels prior to exam (>15ug/ml)

-If no small bowel activity at 60min, consider 4hr and 24hr delayed imaging

-Lack of SB activity at 24hr=biliary atresia (may see vicarious renal excretion and bladder; renal activity can be confirmed with lateral view)

-Delayed SB activity=neonatal hepatitis or biliary stasis

 

SOD

-Aka post-cholecystectomy syndrome

-Pre-treat with CCK to relax sphincter

-Dynamic imaging x60min

-Similar findings as partial CBD obstruction (dilated CBD; delayed clearance of CBD; delayed biliary-to-bowel transit)

-ROI over right hepatic lobe and ROI over CBD

-Refer to journal article JNM 1992 Sostre et al

-Score 0-4=normal; Score 5-12= positive

-Sphincter manometry >40mmHg is gold standard

 

FNH vs ADENOMA

-MUST do flowàthen dynamic imaging x 60minàthen 2-3hr delayed

-FNH has increased flow, immediate uptake by 5-10min (equal to or more than liver), and hot on delayed (20% of FNH may not have any uptake on HIDA)

-Adenoma and some FNH do not have uptake (so if the lesion does not have uptake the exam cannot differentiate btwn FNH and adenoma)

-BEWARE: 50% HCC (esp well differentiated) have uptake on HIDA but are initially cold 10-60min and then variable uptake on delayed (with some cold and some showing retention on delayed mimics FNH)—Hepatomas have uptake on Gallium scan

-Some cirrhotic regenerating nodules may also have uptake on HIDA

 

INFECTION IMAGING with

TAGGED WBC

In-111 oxine WBC

0.5-1.0mCi

or

Tc-HMPAO-WBC

5-10mCi IV

 

 

 

 

Tc-SC

10mCi

IV (for hardware infx)

 

 

● For peds patient prefer HMPAO-WBC (2rad to spleen with HMPAO vs 20rad with Indium)

● Make sure patient is not neutropenic (WBC <2), if neutropenic consider Gallium scan instead (otherwise ABO matched donor WBC may be used)

● For vertebral OM , prefer PET or Gallium (MRI>PET>Gallium)—can be photopenic on Indium if >1mo (but spine hardware infection is better assessed with In-111 WBC)

● Indium less sensitive for:

-chronic non-pyogenic central OM

-follow up of treated OM

-false positive if recent surgery <2wks

● For graft infection, consider Tc-HMPAO-WBC flow, 30min-1hr, and 3hr delayed with SPECT (fusion with CT can improve accuracy)

● Ask if patient is breastfeeding

 

 

HMPAO-WBC

-Preferred for peds and IBD

-For abdominal process:

adults= image at 1hr and 4hr

peds=image at 20min (see bowel activity earlier than adults) and 4hr

-Make patient NPO btwn early and delayed imaging to reduce hepatobiliary excretion

-For OM, image at 4hr (wait 2d after BS)

-For thoracic process, image at 4hr and 8hr

-Lung activity usually clears after 4hr but can persist if pulmonary edema

-Gallbladder activity can be normal

-Tc-HMPAO-WBC cannot be performed simultaneously with Tc-SC rather do it sequentially (HMPAO first and if needed, wait 3d before doing SC)

-IBD=focal/segmental bowel activity that persists on early and delayed imaging (not transient like physiologic bowel)

-Tc-HMPAO SPECT/CT for diabetic foot infx using composite severity index (CSI) proposed by Erdman et al can help guide antibiotic treatment 

-For graft infx, perform flow, 30min-1hr, and 3hr delayed with SPECT (or SPECT/CT)

 

Fever of Unknown Origin (whole body)

-Image at 24hr for Indium

-Useful for vascular graft infx (false positive can be seen with recent surgery <2wks-1month; thrombosis; hematoma/ lymphocele/bleeding; pseudoaneurysm)

-Increased uptake in liver and BM with fragmentation of WBC cells

-Multifocal bilateral lung activity can be due to clumping of WBC rather than septic emboli (also physiologic uptake within lungs first 4hrs up to 24hrs)

-Bowel activity may be due to enteritis/colitis, active GI bleed, tumor, or swallowed WBC (from esophagitis/ sinusitis/pharyngitis), IBD

-Any renal or bladder activity is abnl

-False positives: reactive marrow, sterile hematoma/lymphocele, active aseptic inflammatory arthritis, recent surgery (<2wks), thrombosis, catheter site (including ostomy)

-Cannot assess some surgical wounds like open wound (healing by secondary intention), ostomies (including tracheostomy), skin grafts, bleeding wound because there can be normal accumulation of In-WBC

-Focal or segmental lung uptake is abnl while diffuse homogenous or heterogenous uptake can be due to technical issues

-Graft infection evaluation can be limited by false positive due to thrombosis or recent placement (<2wks) or hematoma (Tc-HMPAO-WBC SPECT may be better)

-Not sensitive for bacterial endocarditis

 

Uncomplicated OM (no prior trauma/surgery/hardware)

-Usually 3phase bone scan can be sufficient to assess for OM

 

Complicated OM (prior trauma/surgery)

-Usually start with 3phase bone scanà if completely normal no further imaging necessary àotherwise need In-WBC scan (wait 24hrs after BS  before injecting In-WBC)

-Optional dual isotope “bone scan + indium” (Inject In-WBCàwait 24hrà Inject Tc-MDPàwait 3hrsàdo simultaneous dual isotope imaging)

-Tc-HMPAO-WBC preferred for peds (wait 2d after bone scan; image at 4hr post-injection)

-Generally like to wait >2wks after surgery to avoid false positive scan

-False positive: aseptic arthritis (like RA)

-False negative ddx: early OM, neonates, elderly with osteoporosis, sig PVD

 

Hardware infection (also charcot joint)

-Hardware infx 1-2% of primary implants and up to 5% of revision implants; 1/3 of these occur within 3mos (early), another 1/3 within 1yr (delayed), another 1/3 >1yr (late)

-Usually start with 3phase bone scan (look for focal uptake greater than iliac crest at femoral tip “tip sign” and trochanters “toggle sign” for hardware loosening or diffuse uptake for infx)ßcan forego BS if do dual-isotope In-WBC/Tc-SC with SPECT/CT

-Some say 3phase BS no better than single phase delayed BS

-Wait 24hrs after 3phase BS before injecting In-WBC

-Prefer simultaneous dual isotope “Indium + sulfur colloid” à discordant uptake on Indium scan suggests infection while concordant uptake suggest non-infectious etiology like redistributed/reactivated marrow

-Inject In-WBC day before imaging and

Tc-SC 30min before on day of imaging

-Simultaneous imaging using MEGP with 10% window at 140keV, 5% narrow window at 172keV, and 15% window at 247keV

-Perform static imaging for 10min

-Consider imaging pelvis for Q.C.

-Need to normalize In-WBC counts to Tc-SC before subtraction (normalize study with lower counts to that of higher counts)

-Tc-HMPAO-WBC cannot be performed simultaneously with Tc-SC rather do it sequentially (HMPAO first and if needed, wait 3d before doing SC)

-S/S of dual isotope In/SC for hardware infx is 96%/87% (accuracy 91%)

 

Marrow imaging with Tc-SC

-Performed 30min after 10mCi Tc-SC IV

-WB drag 5cm/min (slower than bone scan)

-Indications: assess for normal (or marrow hyperplasia) vs abnormal marrow

-Lack of marrow uptake ddx= marrow infarct, OM, tumor (marrow infiltration), myelofibrosis, yellow marrow (inactive)

- Marrow uptake outside normal regions= marrow hyperplasia or regenerative/extra-med hematopoiesis (may be related to chronic hemolytic anemias), myeloproliferative disorders, myelophthisic anemias, chemotoxicity (increasing peripheral marrow uptake after chemo)

-Normal physeal uptake in kids

-Lack of bilateral femoral head uptake can be normal in adults

-Diffuse abnl BM scan is not specific and can be seen with marrow infiltration (like mets) or myelofibrosis

 

INFECTION IMAGING with

GALLIUM

Ga-67 citrate

5-10mCi IV

● If other nuclear medicine test are ordered, prefer to do them before Gallium

● For peds patients prefer HMPAO-WBC scan instead for infx imaging

● No recent blood transfusions or MRI with Gadolinium (wait 24hrs)

● No recent chemotherapy (consider waiting 3wks) for tumor imaging

● Ask if patient is breastfeeding (stop 2wks before exam and indefinitely thereafter)

 

● Use MEGP collimator

● Don’t use 296keV photopeak; in obese pts, also don’t use 93keV photopeak

● 5mCi for infx imaging performed at 24hr (6hr optional)

● 10mCi for tumor imaging performed at 48hr

 

Fever of Unknown Origin (whole body)

-Image at 24hr (48hr optional)

-For abdominal process, may consider 6hr imaging in addition to 24hr

-Gallium may be better than Indium for pulmonary infection/inflammation (if PET is not available) especially in immunocompromised pts--negative scan in untreated pt excludes pulm infx with high certainity (Kaposi is Gallium neg and Thallium pos)

-Lung activity ddx: infection/PNA (including TB/fungal, PCP), ARDS, active IPF, drug toxicity, sarcoidosis

-Mediastinal/hilar LN uptake ddx: sarcoidosis (panda and lambda signs), TB/fungal, lymphoma, smokers (esp hilar uptake)

-Physiologic renal excretion (25%) first 24hr and >24hr predominantly GI excretion

-Physiologic colonic activity can limits detect of intra-abdominal process (in contrast to Indium) 

-Physiologic uptake within breasts, thymic hyperplasia

-Renal uptake greater than spine and equal to or greater than liver (at esp 48hrs) may be due to renal failure, drug-induced renal disease (Acute Interstitial Nephritis due to chemo, NSAIDs), ATN, obstruction, pyelonephritis

-Useful for determination of active granulomatous disease like Sarcoidosis, TB/fungal

-Retroperitoneal fibrosis: positive early during active fibrosis (steroid helpful) and negative late with chronic fibrosis (useful for follow up)

-Altered biodistribution: with iron overload states and recent transfusion (resulting in less liver uptake and more renal excretion)

-Decreased hepatic uptake ddx: altered biodistribution (see above); AIDS; ALL

 

 

OM (limited)

-Usually start with 3phase bone scan

-Wait 24hrs after 3phase bone scan before injecting Gallium

-Image Gallium in similar projections (consider normalizing Gallium scan to total counts on prior bone scan to allow comparison)

-Chronic low-grade (non-pyogenic) OM and f/u of treated OM is better evaluated with Gallium than Indium

-Gallium useful over Indium for vertebral OM (MRI>PET>Ga) and malignant otitis externa or mastoiditis

-Indium preferred over Gallium for hardware infection

-Spatial congruence/incongruence PLUS lesion intensity on Gallium>BS = positive for OM

 

Tumors

-Wait 48hrs before imaging

-Wait at least 2wks after chemo

-Hepatoma/HCC (80% have uptake; 50% greater than liver, 30% iso, 10% less than liver; mimic is hepatic abscess with rim uptake; mets are variable; B9 hepatic tumor like FNH, adenomas, and regen nodules have uptake equal to liver background; hemangiomas are cold)—more sensitive than FDG PET for HCC

-Lymphoma (85% sensitivity for Hodgkin’s and 60% for low-grade NHL so Thallium is better for NHL; cannot accurately assess splenic uptake; helpful for tx monitoring)

-Melanoma (75% of lesions >2cm are avid; sensitivity 82-90%)

-ST Sarcoma

-Lung CA (90% sensitive for SCC >1.5cm)

-Testicular CA (90% sensitive for Seminomas; 25% for Teratomas)

-Kaposi sarcoma is Gallium neg and Thallium positive

-Brain Toxo vs Lymphoma: both are Gallium positive while Toxo is neg on Thallium

-Thymic rebound in Gallium positive and Thallium negative

-Usually no marrow uptake on Thallium scan

 

LIVER-SPLEEN SCAN

Tc-SC

5mCi IV

(0.1-1.0um)

 

 

Tc-SC 10mCi for marrow imaging

● No patient prep (no contraindication in sulfa allergy)

● Prefer lesion size >1.5 cm

● Prefer heat-damaged Tc-RBC scan for detection of small splenic tissue (splenosis)

● For large peripheral lesion suspected to be FNH, consider HIDA scan

● Wait 30min before imaging

● Normal distribution: 85% liver (kupfer cells), 10% spleen, <5%BM (largest particles to spleen and smallest to BM)

● Static imaging in multiple projections along with ant view with lead ruler over liver (ruler is 14cm length and 5cm width with holes 9mm in diameter)

● Consider SPECT (prefer SPECT/CT) imaging if assessing for focal hepatic or splenic lesion

● Normal Liver ≤18cm (ant view) and Spleen≤13cm (post view)

● Kids <18yo, max spleen size = 5.7 + (0.3 x age in yrs)

● Massive splenomegaly=CML, myelofibrosis, thalassemia, glycogen storage dz (Gaucher)

● Decreased spleen uptake=?recent chemo, antimalarial drugs, lymphoma

● Spleen:Liver ratio >1.5 suggest colloid shift (cirrhosis, portal HTN, hepatitis, chronic passive congestion, hypersplenism, marrow-active anemia in response to chemo)

● FNH: 2/3 have uptake (1/3 hot, 1/3 iso) and 1/3 are cold

● Cold liver lesion=long ddx (including adenoma, 1/3 FNH, HCC, abscess, hemangioma, mets etc)

● BM defect ddx: infarct, OM, marrow infiltration (tumor)

● Abnormal BM uptake may suggest extramedullary hematopoiesis

● Lung uptake ddx: colloid clumping (large particle size), improper prep with Al/Fe contamination, severe cirrhosis, hypercoag state, normal in kids  (minimal)

● Hot caudate lobe=Budd Chiari

● Hot quadrate lobe (seg IV)=SVC obstruction

● Uptake in transplant kidney=chronic rejection

 

Marrow imaging:

● Performed 30min after 10mCi Tc-SC IV (higher dose)

● WB drag 5cm/min (slower than bone scan)

● Indications: assess for normal (or marrow hyperplasia) vs abnormal marrow

● Lack of uptake ddx= marrow infarct, OM, tumor (marrow infiltration), myelofibrosis, yellow marrow (inactive)

● Marrow uptake outside normal regions= marrow hyperplasia or regenerative/extra-medullary hematopoiesis (may be related to chronic hemolytic anemias), myeloproliferative disorders, myelophthisic anemias, chemo toxicity (increasing peripheral marrow uptake after chemo)

● Normal physeal uptake in kids

● Lack of bilateral femoral head uptake can be normal in adults

● Diffuse abnl BM scan is not specific (can be seen with marrow infiltration like mets) or myelofibrosis

 

Heat-damaged RBC:

● 3mCi heat-damaged Tc-RBC IV (49degC or 120degF x 20min in water bath) 

● Image 1hr after injection

● May do SPECT (or SPECT/CT)

● Sequestration by spleen (90% splenic uptake as opposed to 10% with liver-spleen scan)

● Overheating=increased uptake by liver; Underheating=more BP activity

● Indications: splenosis, accessory spleen, heterotaxy syndrome, splenic infarct, wandering spleen (volvulus or infarction), prior splenectomy (hereditary spherocytosis and ITP/TTP),

 

LYMPHO-SCINTOGRAPHY

Tc-SC (filtered)

0.5-1.0mCi intradermal (divided into 2-4equal doses of 0.1cc volume each)

 

Tc-Tilmanocept/Lymphoseek

0.5-1.0mCi intradermal

● No patient prep

● Ice pack or topical lidocaine cream

optional before injection

● Gabauer’s skin refrigerant “Pain Ease” for topical skin anesthetic at time of injection

 

● Filter Tc-SC using 0.22u (micromillipore) filter to get <0.1um particle size

● Use 1mCi total if lymphoscintigraphy is being performed day before surgery

● Use 30G needle on tuberculin syringe for injection and raise a wheal

● Co-57 pen point-marker for localizing lesion and marking overlying skin

● Lymphoseek mannose agent bind with high affinity to CD206 receptor proteins on macrophages and dendritic cells

 

Breast CA

-Peri-areolar injections (preferably in same quadrant as known tumor)

-Some perform peri-tumoral injections if tumor is palpable

-Usually without imaging

 

Melanoma and other skin CA

-Peri-tumoral injections (avoid injecting the scar)

-Dynamic imaging x60-90min

-Static imaging with masking of injection site with lead and also static transmission imaging with Co-57 sheet source on opposite detector

-Localize and mark overlying skin

-Not useful if lesion deeper than 4mm Breslow

-For H&N lesion, inject smaller volume (0.05cc) and don’t inject caudal to lesion

-Also indicated for oral cavity SCCA (inject 1d before surgery) along with vulvar and penile CA

 

Lymphedema

-Use 0.5-1.0mCi Tc-SC (not Lymphoseek)

-Inject between web of 1st/2nd toes/fingers of bilateral extremities

-Static imaging x2-4hrs (distal to proximal to follow transit of tracer centrally)

-Look for disruption of deep lymphatics with dermal backflow via superficial lymphatics

-Image over liver at end of exam

-Cisterna chyli (saccular area of triangular dilation of lymphatic channels at right retrocrural space at level of L1 and T12 btwn aorta ad azygous vein measuring 5-7cm in CC)àthoracic ductà moves to left at T5 (medial to hemiazygous) and enters sup mediastinum located behind aortic arch and left of esoà empties at jct of left subclavian and IJ veins  

 

Chylothorax (thoracic duct injury)

-Use Tc-SC (not Lymphoseek)

-Inject in feet and delayed imaging to look for thoracic duct leak into pleural cavity

 

MECKELS

Tc-Pertech.

0.05mCi/kg

IV (peds)

 

(10mCi IV for adults)

● NPO x4-6hrs

● For peds: give H2 blocker (not PPI) like Cimetidine (Tagamet) 10-20mg/kg PO for 2days before exam and additional dose 1hr before exam

● For adults: give H2 blockers (not PPI) like Ranitidine (Zantac) 150mg PO bid or Cimetidine (Tagamet) 300mg PO qid 1day before exam

● PPI like Prilosec/Nexium/Prevacid/ Aciphex don’t work

 

● Pre-treat with Pentagastrin to promote uptake by mucin cells (not used) ; H2 blocker to block release (prefer); Glucagon to inhibit peristalsis (not used) 

● Place patient in supine and left oblique position (put wedge under right side) to avoid emptying of gastric mucosal activity into small bowel

● Dynamic anterior imaging x90min

● Post-void anterior and right lateral static views are helpful

● Optional 2hr delayed static

 

INTERPRETATION

● Heterotopic gastric mucosa in 1/3 of Meckels

● Usually appears within 30min (but can take up to 1hr depending upon amount of gastric mucosa), intensifies with time (equivalent to gastric activity), and remains focal (does not show peristalsis)

● False positives: renal collecting system, ureteral activity, IBD, appendicitis, duplication cyst, barrets eso, tumors like carcinoid/polyps

● Rules of 2s for Meckels: >50% are symptomatic before age 2; 2feet from ileocecal valve; 2inches in length; 2% of population; 2:1 M:F

 

MIBG

(Tumor)

I-123 MIBG

10mCi IV slow (over 5min)

 

 

0.14mCi/kg IV for kids (range 1-10mCi)

● Obtain complete medication list before scheduling patient

-AntiHTN (labetelol/reserpine/ CCBlockers, ACE-I)ßother beta blockers ok; TCAntidepressants (like amitriptyline etc); Antipsychotics; Sympathomimetics may need to be held for 2d to 1wk (see EANM guidelines for details)

-Discuss with provider before stopping anti-HTN meds in patients with Pheo (risk of hypertensive crisis)

● Consider premedication with Ondansetron (Zofran) for potential N/V before exam

● Ask patient to avoid chocolate or cheese (esp blue-vein cheese) x24hr before exam

● Ask if patient is breastfeeding

Block thyroid uptake by giving equivalent of 100mg elemental iodine per day starting 1d before exam and continue for additional 3d for I-123 and 5d for I-131 after injection

 

 

-KI 130mg tab qd (iodide) or 170mg tab qd (iodate) x3d (starting 1d b/f exam) for adult ßadjust dose for kids per EANM guidelines

-Alternatively, 1% Lugol solution 1drop/kg/day divided in equal doses (with max of 40 drops/d) x3d (starting 1d b/f exam)ß no dose adjustment needed for kids (preferred for infants)

-If allergic to iodine or risk of thyrotoxicosis, use Potassium Perchlorate 400mg tab qd x3d (starting 1d b/f exam)ßadjust dose for kids per EANM guidelines

 

 

● NE analog (active reuptake into presynaptic neurons)

● Avoid injecting via central line

● Image 4hr and 24hr with I-123 MIBG (5cm/min for WB and consider SPECT/CT)

● Potential side effects: tachycardia, N/V, abd pain, pallor

● Risk of hypertensive crisis in patients with Pheochromocytoma (start >22G IV; monitor HR and BP during slow IV injection)àstop injection if unstable hypertensionàtreat with short-acting alpha blockers IV (5mg Phentolamine IV)àuse short-acting beta blockers (like Esmolol IV) if tachycardia occurs

 

INDICATIONS:

-Neuroblastoma (better than PET/CT for marrow involvement)

-Pheochromocytoma (PET/CT sensitivity and NPV for Pheo is high but specificity and PPV is lower; MIBG higher specificity than CT/MRI; rules of 10s= 10% malignant, 10% bilat; plasma free or urine Metanephrines; urine VMA)

-Certain Paragangliomas (extra-adrenal sympathetic paragangliomas esp intra-abdominal; octreoscan better for parasympathetic paragangliomas of H&N)

-MEN syndromes:

MEN1=pit/panc/parathyroid MEN2a=pheo/MTC/parathyroid MEN2b=pheo/MTC/neuroma

 

 

INTERPRETATION:

● Physiologic uptake: salivary gland, nasal mucosa, thyroid, heart (variable; less with pheo; high in <6yo), lung (esp DM with symp nerve dysnfxn and high-altitude sickness; less in emphysema), adrenal medulla (critical organ; esp with I-123 but <<liver), liver>spleen, brown fat, bladder, uterus

● MIBG better than PET/CT for bone/BM mets for neuroblastoma (stage III and IV)

● De-differentiated CA is MIBG neg but FDG PET positive

 

 

MIBG

(AdreView)

I-123 MIBG AdreView

5-10mCi IV over 1min

● Make sure patient has recent resting MPS (to detect infarcts)

● Hold meds x24hrs (same list as MIBG above)

● NPO x6hrs

● Thyroid blocking with KI tablet 1d before, same day, and 1d after

 

● Adrenergic cardiac imaging for heart failure (sympathetic/autonomic dysfunction in NYHA class 2-3 HF with LVEF≤35%)

● High specific activity formulation by G.E.

● Early (15min) planar anterior heart/mediastinum x10min

● Delayed (4hr) planar anterior  heart/mediastinum x10min

● Draw 20x20 pixel ROI over mediastinum and over heart and get mean or average counts

● Sensitivity: CT/MRI > MIBG

● Specificity: MIBG > CT/MRI

 

INTERPRETATION:

-Normal H:M ratio in normal non-CHF patient is >2.2

-For CHF patients, normal H:M ratio >1.6 (at 4hr) and normal washout <10% [washout= (initial myo – delayed myo) / (initial myo) x 100]

-Normal relatively less uptake in septum, inferior, and apex (compared to ant and lat walls) in healthy pts

-H:M ratio <1.6 (at 4hr) predicts poor prognosis (higher rate of worsening NYHA class, life threatening arrhythmia, cardiac death); also washout ≥27% has poor prognosis and lower likelihood for benefit from ICD

 

MILK SCAN

Tc-SC 0.1-1.0mCi in milk/formula via bottle

● For neonates and infants

● 2 day study

Hold last feeding prior to scan

Bring 4oz of milk/formula in bottle (bring extra empty bottle)ßinquire how much baby drinks when hungry

● No sedation

 

● Supine imaging is preferred

● Prefer oral feeding but can use feeding tube like G-tube (if using NGT, consider removing it after administration)

● For kids on tube feeds: hold feed x2-4hrs;  figure out what they normally get per hour (eg 30cc/hr) and then give ½ hour worth (eg 15cc) of feed as a bolus and flush with some unlabeled water or feed

 

Day1 (swallowing study and rule out aspiration):

-0.1mCi Tc-SC in 2cc milk via syringe (may follow with unlabeled milk)

-Posterior dynamic supine imaging (20s/fr with zoom) over chest (from mouth to stomach) for 30min to 1hr

-2-4hr delayed posterior chest static image (for aspiration) with transmission

 

Day2 (Reflux and Gastric emptying study):

-Start with posterior chest static image (12-24hr delayed) to rule out aspiration from day1 study (terminate if aspiration is confirmed)

-0.5-1.0mCi Tc-SC in 4oz milk via bottle (half labeled and half unlabeled; adjust volume based on baby age)

-Posterior dynamic supine imaging (10-20s/frame with zoom) over upper abdomen for 1hr (for reflux detection—record number of events, duration <10s or >10s, level above/below mid eso)

-Take 1 min static image of abdomen at end of 1hr (for gastric emptying)

-Additional 2hr and 3hr delayed static image of abdomen (for gastric emptying)

-Normal GE emptying is ~50% at 1hr for breast milk and 90min for formula (?)

 

MUGA

Tc-RBC

20-30mCi IV

(in-vitro labeling “ultratag” efficiency 98%)

● Avoid caffeine 2hr before exam

● Consider obtaining rhythm strip before injecting (to assess for arrhythmia)

● Poor labeling with Heparin, Digoxin, Hydralazine etc

● Stannous ion (reducing agent) Tc+7 à Tc+4

● Gated (16-32 frames/cycle) dynamic imaging in best septal view usually 45deg LAO (with 10-15deg caudal tilt to separate LA from LV)

● Frame rate <50ms/fr (prefer <30ms/fr or 32fr/cycle for diastolic parameters)

● R-R interval tolerance usually +/- 20% (up to 40%)

 

INTERPRETATION:

● Frequent aberrant beats or arrhythmia (especially with >30% rejected beats) may make quantitative LVEF assessment unreliable (>10% makes diastolic assessment unreliable)

●LVEF ≥50% at rest

● Normal %regional shortening at least 25% (hypokinetic btwn 10-25%)

● Phase=timing (sequence) of contraction; Amplitude=relative magnitude of contraction (aka stoke volume)

● Paradox image= ES image – ED image (look for aneurysm seen as unsubtracted systolic bulge)

● EF = (EDV-ESV) / (EDV-background)

● Overestimation of background overestimates EF; inclusion of LA underestimates EF; gating issues usually underestimates EF; LVH underestimates EF

● Normal EF should increase by 5-7% with exercise (decrease in EF with exercise suggest MVD or aortic valvular dz)

● MPS (8fr/cycle) underestimates EF by 5% (over-estimates if small heart); 3D ECHO also tends to underestimate EF; SPECT MUGA (GBPS) overestimates EF by 7-10%

 

DRUG TOXICITY:

● Drug-related cardiotoxicity in pts with baseline EF>50% : discontinue if LVEF drops ≥10% from baseline AND absolute LVEF reaches below 50%

● Drug-related cardiotoxicity in pts with baseline EF<50% : discontinue if LVEF drops ≥10% from baseline OR absolute LVEF reaches below 30%

● Herceptin (Trastuzumab)—usually reversible cardiotoxicity

● Anthracycline (Doxyrubicin/Adriamycin) —dose dependent >400mg/m2 (toxicity may be irreversible)

 

DIASTOLIC PARAMETERS:

● QC for diastolic assessment:

-≤30ms/fr and 32fr/cycle

-R-R tolerance +/-10%

-rejected beats  <10%

-ED counts at beginning of LV curve should equal the end of curve

● Normal diastolic parameters (from derivative diastolic curve):

-isovolumetric relaxation 50ms (HOCM >90ms)

-TTPF <180ms (abnormal >217ms)

-PFR >2.5EDV/s (abnormal <1.7EDV/s)

● May consider diastolic dysfunction is normal LVEF but abnormal LV volumes

● Increased TTPF rate with restrictive CM

 

MYOCARDIAL PERFUSION

Tc-sestamibi

10-40mCi IV (weight-based dose adjustment)

 

 

Thallium-201 3-4mCi IV (if there is Tc shortage)

 

 

 

LEXISCAN

Regadenoson

0.4mg (5cc) IV over 10s via 22G followed by 5cc NS àinject tracer after 20s followed by 5cc NS

 

 

ANTIDOTES:

Aminophylline 50-100mg IV slow over 30-60s (max 250mg)—wait at least 2min after tracer;

Atropine 0.5mg IV for low HR;

NTG 0.5mg SL q5min (max 3 doses in 15min)

 

● NPO x4hrs (ok to take medications with sip of water)

● Keep well hydrated

● No nicotine or caffeine (coffee/tea/decaf/chocolate/soda) 12-24hr before exam (also no theophylline x24hrs)ßherbal tea is OK

● No NTG x4-6hrs and nitrates x12hrs

● Ask patient to bring any inhalers for asthma/COPD with them

● Patients may have been asked by their doctor to stop beta-blockers x24hrs or meds containing theophylline x48hrs

● Wear comfortable clothes and jogging sneakers (possible treadmill stress)

● Don’t apply lotion/oil/powder to chest area (EKG leads won’t stick)

● Wait 2-4wks after PTCA

 

 

SOME APPROPRIATE USES:

-Asymptomatic with high CHD risk >20% Framingham or 7.5% 10-yr risk

-Asymptomatic with CAC>400 (or CAC 100-400 with high CHD risk)

-Symptomatic with int (10-90%)/high (>90%) pretest prob for CAD

-Symptomatic with low pretest prob (<10%) for CAD but uninterpretable EKG or unable to exercise

-ACS without EKG changes and neg Troponins

-Elevated Troponins without evidence for ACS

-New onset CHF with systolic dysfxn and no prior hx of CAD

-Known CAD with new or worsening symptoms and prior abnl MPS or cath >2yr ago

-Known CAD with coronary stenosis <70% of unknown significance

-Preop clearance for intermediate risk (1-5%) surgery or vascular surgery (>5%) with ≥1 clinical risk factors + poor or unknown functional capacity

 

 

MOST COMMON INAPPROP USES:

-Asymptomatic pt with low CHD risk <10%

-Asymptomatic pt with known CAD s/p revascularization <2yr (surveillance)

-Stable symptomatic CAD s/p cath <1yr or recent abnl MPS

-Symptomatic with low pretest prob (<10%) and interpretable EKG and able to exercise

-Preop clearance for low risk surgery

 

SYMPTOMATIC PRE-TEST PROBABILITY OF CAD:

<5% very low

5-10% low

10-90% intermediate

>90% high

 

ASYMPTOMATIC CV RISK CALCULATOR 2013 (ACC/AHA):

20-79yo (less useful for DM or PVD)

<7.5% low 10yr risk

≥7.5% high 10yr risk

 

HEART SCORE (E.R. patients):

H=history

E=EKG

A=age

R=RF

T=Troponin (1time)

0-3=low risk <2% MACE at 6wks (d/c)

4-6=mod risk 20% MACE at 6wks (admit)

7-10=>50% MACE at 6wks (cath)

 

PRE-OP SURGERY EVALUATION:

Low <1% (ambulatory, endoscopy etc)

Int 1-5% (H&N, CEA, Ortho, Intra-peritoneal, Intra-thoracic)

Vascular >5% (PVD, Aortic etc)

 

 

PROCESSING:

-Mibi (ungated) FBP BW cutoff 0.7 & order 3

-Mibi (gated) FBP BW cutoff 0.4 & order 3

-Mibi IR iteration 6 and subset 8 (add Hanning cutoff 0.6 – 1.0)

 

 

1 day mibi protocol

-10mCi Tc-mibi IV at rest followed by 30mCi Tc-mibi IV at stress

-Preferred protocol for inpatients/ED and non-obese patients (generally <250lbs)

-Prone imaging in obese helps inferolateral artifact from diaphragm but may introduce anteroseptal artifact

-Seated imaging decreases inferior artifact from diaphragm but shifts pendulous breast attenuation artifact from anterior wall to inferoapical wall

-Attenuation correction with SPECT/CT preferred for obese patients (best for inferior wall dia attenuation but not so effective for anterior wall breast atten; may result in prominent apical thinning; misreg with high density results in hotspot while misreg with low density like lung results in defect; heart misreg into lung usually results in anterolateral defect; AICD leads result in basal inferoseptal hot spot; arms down usually results in septal defect; metallic valves usually no issue)

-General SPECT is 180deg rotation from RAO to LPO with 32stops and 40s/stop

 

2 day mibi protocol

-Prefer for obese patients BMI>30

-Start with 30-40mCi Tc-mibi IV at stress

-If stress imaging is normal, doc may cancel resting portion

-Can gate both stress and rest

 

Planar MPS (2 day)

-For obese patient who exceed table weight limit (or those who can’t lay flat on imaging table)

-Obtain LAO, RAO, and Left Lateral non-gated static views at stress and rest (make sure imaging planes are similar)

-On LAO projection can evaluate anteroseptal and inferolateral walls

 

Thallium MPS (1 day)

-Only utilized if there is Tc shortage or desire to perform MPS + viability together

-Higher radiation dose than Mibi

-3-4mCi Tl-201 IV at gated stress (wait 10-15min before imaging) followed by same day resting imaging at 2.5-4hrs

 

 

QUANTITATIVE:

-SSS <4=normal, 4-8=mild, 9-13=mod, >13=severe

-SDS ≤2=no ischemia, >7=sig ischemia

-QPS <2.0 SD from mean is normal

-LHR<0.5 (Thallium) and <0.4 (Mibi)

-TID<1.2 (treadmill) or TID<1.4 (pharm)

-Systolic wall thickening >35%

-EDV<140-180cc

-ESV<70cc (<20cc overestimates EF)

-Drop in post-stress EF by >5% compared to resting EF is suggestive of ischemia

-Significant ischemia ≥10-15% of LV myo (ischemia >20% show clear benefit from revascularization over medical therapy)

-Ventricular dyssynchrony: Phase SD or BW ≥19.6deg (non-uniform phase polar map), Histogram BW ≥72.5deg (wide phase histogram), and LV-RV delay >40ms suggest response to CRT

 

PROGNOSIS:

-NORMAL MPS with SDS=0-1 (annualized risk of cardiac event <1% for both cardiac death and non-fatal MI; 1.9% for DM pts)

-MILD ABNL MPS with SDS=2-4 (Low risk 2.6% of cardiac death and intermediate risk for non-fatal MI)

-MOD-SEVERE ABNL MPS with SDS>4 (int-to-high risk 4.7% for both)

-Increased risk over others despite normal MPS if: male (non-DM), DM (esp females), increasing age >60yo, known CAD, chemical stress (instead of treadmill)

-Bad prognosis if EF ≤45% (esp if <30% regardless of amount of ischemia)

-High risk MPS: extensive ischemia (>20% of LV); ischemia in more than 1 coronary territory; +TID; abnl LHR (on Thallium)

-During treadmill, development of frequent ectopy (>7 PVC/min), bi/trigeminy, couplets/triplets, V-tach, Afib/flutter, or Torsades predicts sig ischemic burden

-In post-MI period, EF<40% is associated with increased risk (~40%) for subsequent cardiac events

-Limitations of MPS: misses multivessel disease (underestimates dz); not sensitive for early disease; normal MPS does not rule out CAD; FP due to attenuation artifact (overcalls dz)

 

STRESS PROTOCOL:

● CHEMICAL STRESS

-Adenosine (A2A agonist; 140ug/kg/min; 4 or 6min infusion with tracer injected at 2 or 3 min respectively)

-Lexiscan/Regadenason (selective A2A agonist; T1/2 of <10min as opposed to adenosine which is only 10s)

-Persantine (Blocks adenosine deaminase; 140ug/kg/min; 4min infusion with tracer injected 3min after end infusion)

-Dobutamine (b-1 agonist) 5-10ug/kg/min (max 40)  q3min (+/- 0.5mg Atropine IV max 25mg) with Esmolol 0.5mg/kg over 1min as antidote

-Side effects of Lexiscan (selective A2A agonist): headache/flushing, CP/SOB, N/V/abd pain

-Complications of Lexiscan: AV block, bronchospasm, hypotension

-Contraindications: hypotension (SBP<80mmHg), bradycardia (<40bpm), actively wheezing, 2nd/3rd degree AV block (unless paced), caffeine <12hrs, pregnancy/breastfeeding, avoid Lexiscan in acute MI

● TREADMILL/EXERCISE STRESS

-Bruce goal 85% of MPHR (220-age)

-Good prognosis: exercise time>12min (stage4), METS ≥10 (best), DP>20K, Duke≥+6 (Duke <-11 is bad)

-Contraindications to treadmill stress: high risk unstable angina; decompensated CHF; symptomatic arrhythmia; severe AS; acute PE/MI/dissection/myocarditis/pericarditis; severe pulm HTN; known LAD stenosis (relative); HOCM (relative); high degree AV block w/o pacer; cannot assess EKG (LBBB, WPW, Digoxin, LVH)

-Terminate treadmill test early if: symptomatic ST depression ≥3mm horiz/downsloping (esp if develop early in exercise within first 4min); ST elevation >1mm w/o Qwave; sig CP/DOE; poor perfusion (cyanosis/pallor); neuro symptoms (ataxia/near syncope); new LBBB; sustained VTac; SVT; SBP drops 10mmHg from baseline; HTN crisis SBP>250 and DBP>115; technical difficulties with monitoring patient (equipment failure)

-Note: pacer is not a contraindication

-Development of frequent ectopy (>7 PVC/min), bi/trigemini, couplets/triplets, V-tach, Afib/flutter, or Torsades predicts sig ischemic burden

 

EKG:

-II, III, AVF=inferior

-V1, V2=septal

-V3, V4=anterior

-I, AVL, V5, V6=lateral

-Leads V5 and V6 leads are most S/S for monitoring for ischemia during stress test

-ST depression 2mm horizontal or downsloping is concerning

-ST elevation >1mm without Q-wave is concerning

 

COMPARISON WITH OTHER MODAILITIES:

-Stress ECHO is less sensitive but more specific (operator dependent; limited if pre-existing WM abnl like LBBB/digoxin etc)

-Rb-82 PET/CT: same sensitivity (89%), higher specificity (90%) and higher accuracy than MPS (86%/74%); rest EF and “peak” stress EF; total imaging time 45min; perfusion quantification like MBF=myocardial blood flow and CFR=coronary flow reserve >2.5-3.0 (higher extraction fraction than Tc-mibi); better for BMI>30 (CT attenuation correction)

-Solid-state gamma camera have 5-10x sensitivity and have higher spatial/contrast/energy resolution than conventional gamma cameras

-RADIATION DOSE:

Thallium/mibi          27mSv

2day mibi/mibi        20mSv

1day mibi/mibi        13mSv

Mibi stress only       10mSv

Rb-82 stress/rest      7mSv

F-18 viability             5mSv

 

MYOCARDIAL VIABILITY

Thallium-201 3mCi IV

 

(1mCi re-injection for 24hr imaging)

 

 

● Same prep as Myocardial Perfusion Scan (see above)

● Make sure patient has recent MPS

 

● Performed in patients with ischemic heart failure (CAD with fixed non-reversible defects on MPS and depressed EF) to look for viable or hibernating myocardium and to predict improvement in LVEF with revascularization

● Thallium has higher first pass extraction (85%) than mibi (50-60%) and shows re-distribution (but also has higher effective dose than Tc-mibi)

● STICH TRIAL (NEJM 2011): Assessment of viability does not identify patients who will have survival benefit with revascularization over aggressive medical therapy

 

 

Thallium viability-only (prefer)

-Make sure patient has recent MPS

-3mCi Tl-201 IV at rest (image within 10-15min) followed by 4hr and 24hr re-distribution imaging

-Re-inject 1mCi Tl-201 prior to 24hr imaging

 

Thallium MPS (ischemia) + viability

-Only performed at request of ordering physician especially if no recent MPS exam

-3mCi Tl-201 IV gated stress (image within 10-15min) followed by 4hr resting and 24hr re-distribution imaging

-Re-inject 1mCi Tl-201 prior to 24hr imaging

-MPS=stress and 4hr resting (evaluate for ischemia)

-Viability=24hr redistribution (compare to stress)

 

PET Viability

-Make sure patient has recent MPS for comparison (if not consider obtaining hi-dose gated rest MPS day before exam)

-S/S 93%/58% (Thallium 86%/59%)

-NPO x6hrs

-Glucose-loading protocol (50g glucose PO vs 50% dextrose with 20mg hydrocortisone IV)

-PO protocol: FBG<125 give 50g glucose PO; FBG 125-225=give 25g PO; FBG>225=no glucose

-IV protocol: FBG<125=give 25g 50% dextrose IV (over 15min); FBG 125-225=give 13g IV; FBG>225=no dextrose

-Give insulin aspart (Novolog) IV per sliding scale (target is FBG≤150)

-Check FBG q15-30min along with vitals

-When FBG≤150 à inject 10mCi FDG IV

-Wait 60min before imaging

-Obtain cardiac PET/CT in 1 bed position from carina to below dia (10min) without EKG gating

-check FBG before letting patient go (make sure FBG>60; give OJ if low)

-Recon data in same projections as MPS (short and long axis)

-Look for “perfusion-metabolism” mismatch (≥30% LV viability is considered significant)

 

IMPRESSION:

-[Absent/reduced] perfusion and metabolic activity confirms nonviable [] wall infarct.  Functional recovery after revascularization is highly unlikely.

-[Reduced] perfusion with only [mild] mismatched metabolic activity suggests co-existing non-transmural infarct and partially viable [] wall myocardium.   Partial functional recovery after revascularization is possible.  

-Absent perfusion but [normal/high] metabolic activity (perfusion-metabolism mismatch) confirms [] wall viability.  Functional recovery after revascularization is likely.

-Resting LVEF of [] with [normal/abnormal] wall motion from MPS.

 

 

OCTREOSCAN

In-111 Pentetreotide 6mCi IV

 

● Obtain complete medication list before scheduling patient--hold short-acting somatostatin analogues (Sandostatin or Octreotide acetate, Lanreotide or Somatuline, Pasireotide or Signifor) for 2d and longer-acting like Sandostatin-LAR depot for 4wks

● If history of Insulinoma, may not d/c somatostatin analogues due to potential sig hypoglycemia

● Encourage hydration before exam (to aid renal excretion)

● Ask if patient is breastfeeding

● Avoid in kids (high dose to spleen ~15rads)

● If DM, consider holding insulin on day of exam (to avoid hypoglycemia)

 

 

● If history of Insulinoma, starting IV fluid with dextrose before and during injection to avoid hypoglycemia (monitor BG)

● Do not inject in line used for TPN (also hold TPN before injection)

● MEGP collimator

● WB imaging at 4hr (less bowel activity), 24hr, and 48hr

● 24hr and 48hr SPECT (prefer SPECT/CT)

● Potential side effects: hypoglycemia, dizziness, hypotension, HA, flushing, fever

● Somatostatin (SST) receptor subtypes 2 and 5

● Syndromes:

-Carcinoid syndrome (hepatic mets): FDR (flushing, diarrhea, right heart failure)

-ZE syndrome (gastrinoma): GI bleed, GERD, abdominal pain

-WDHA syndrome (VIPoma):watery diarrhea, hypoK, achlorhydria

 

INDICATIONS:

-Carcinoid (typical)—PET/CT better for atypical carcinoid

-Islet cell tumors (less sensitive for insulinoma and somatostatinoma)

-MTC (Octreoscan more sensitive than MIBG; can do FDG PET/CT for recurrent MTC; follow with serum calcitonin and CEA levels)

-Paraganglioma (parasympathetic H&N)

-Small (oat) cell lung CA

-Thyroid opthalmopathy (image at 4 and 24hr; orbit to brain ratio >10 or orbit to occipital skull ratio >1.85; positive scan suggest active disease which is responsive to immunosuppressive tx like steroids, XRT, somatostatin analogs)

 

 

INTERPRETATION:

● Physiologic uptake: pituitary, thyroid, gallbladder, breasts

● Compare activity to liver (0=none; 1=very low or equivocal; 2=mild ≤liver; 3=moderate >liver; 4=intense >>liver)

● Hepatic mets in carcinoid may appear isointense relative to hepatic parenchyma (SPECT is useful)

● PET/CT is better for atypical carcinoid (increased mitotic activity 2-10 per 10HPF; nuclear pleomorphism; foci of necrosis) and de-differentiated NET

● Reduced splenic activity if patient is still on somatostatin analogues

● Can see uptake in meningioma; astrocytoma/medulloblastoma; pituitary adenomas; subacute thyroiditis; thyroid ophthalmopathy (orbit to occipital skull ratio >1.85 is positive); Merkel cell skin CA; breast CA; lymphoma (Hodgkins>NHL); RA; granulomatous process like sarcoid/TB and at sites of inflammation due to activated leukocytes (like Gallium scan)

● Labs for carcinoids:

-5-HIAA (urine)=serotonin metabolite (50% reduction suggests response)

-ChromograninA (serum)=not as specific (can be 100-1000x normal in mid-gut carcinoids)

● MEN syndromes:

MEN1=pit/panc/parathyroid MEN2a=pheo/MTC/parathyroid MEN2b=pheo/MTC/neuroma)

 

Ga-68 DOTATOC/DOTATATE PET SCAN:

-More sensitive than In-111 Octreoscan

-Need Ge-68/Ga-68 generator (Ga-68 is a positron emitter with T1/2 of 68min)

-Normal uptake: spleen>liver, pituitary (no uptake in brain), thyroid, renal (less uptake than seen with Octreoscan)

-DOTATATE=NETSPOT

-Both can be used for PRRT with Y-90 or Lu-177 respectivelyßkidneys and BM are dose-limiting organs

-Lu-177 DOTATATE or Lutathera therapy (currently in clinical trials)

 

PARATHYROID SCAN

Tc-mibi

20-25mCi IV (don’t use Myoview)

 

 

 

Tc-pertech.

5mCi IV vs

I-123 0.2-0.4mCi PO (for thyroid scan)

● No patient prep

● Ask patient if they are taking Synthroid, PTU, Methimazole/Tapazol (which may interfere with optional thyroid scan)

● Mibi taken up by Oxyphil cells (not chief cells)

● Tc-Myoview: cannot do delayed imaging since parathyroid adenoma washes out unlike Tc-Sestamibi

● Primary HPT (80% parathyroid adenoma): normal or high PTH (>60pg/ml)àhigh serum calcium (>10.4mg/dl), ionized serum calcium (>5.2mg/dl), urine calcium (>150mg/24hr)

● Secondary HPT (parathyroid hyperplasia due to chronic renal dz leading to hypocalcemia): abnormal renal fxnàlow serum calcium (initially low and later normalizes) àhigh PTH

● Familial hypercalcemia hypocalcuria (no surgery needed): high serum calcium but normal urine calcium

● MEN I and IIa (familial): multiple adenomas

MEN1=pit/panc/parathyroid MEN2a=pheo/MTC/parathyroid MEN2b=pheo/MTC/neuroma

 

 

Dual phase Parathyroid only

-20min (early) and 2hr (delayed) pinhole neck and wide FOV (include mediastinum) imaging (10min planar projections)

-Delayed SPECT (or SPECT/CT) is useful

 

Thyroid-Parathyroid subtraction (prefer)

 

1. Dual-isotope with Tc-pertech/Tc-mibi

-Sequential (non-simultaneous) dual-isotope imaging with subtraction

-Inject 5mCi Tc-pertechnetate IV and wait 20minà take an image (thyroid scan) à without moving the patient inject 20-25mCi Tc-mibi IV and take another similar image after 20min (early parathyroid scan) à bring patient back for additional 2hr imaging  (delayed parathyroid scan)

-Normalize counts and subtract Thyroid from early Parathyroid scan (motion artifact can limit subtraction)

-Persistent thyroid activity limits assessment of delayed parathyroid scan

 

2. Dual isotope with I-123/Tc-mibi

-Simultaneous dual-isotope imaging with subtraction

-Give 0.2-0.4mCi I-123 PO in AM

-After 3.5hrs inject 20mCi Tc-mibi IV and wait another 20min

-Do simultaneous acquisition (use +/- 7 to 12% window around Tc 140keV and +/- 4 to 8% window around I-123 159keV) 

-Planar neck (with pinhole) and wide FOV (include mediastinum)

-Normalize counts and subtract I-123 from early Tc-mibi

-Optional: delayed Tc-mibi after another 2hrs

 

MIRP:

-Pre-op 10mCi Tc-mibi IV (2-4hr prior to surgery)

-Use gamma probe to locate gland with counts 20-50% greater than background

-Intra-op PTH assay (look for PTH decrease by 50-70%)

 

INTERPRETATION:

-Primary HPT= result in renal stones, nephrocalcinosis, osteoporosis (cortical>cancellous), insufficiency fractures, pancreatitis, etc

-Ectopic gland can be anywhere from angle of jaw to aortic arch (including retropharyngeal/retrolaryngeal, intra-thyroidal, carotid sheath, paraesophageal, thymus, ant/post mediastinum, etc)

-Anterior mediastinal adenoma are usually inf gland fallen caudally while posterior mediastinal adenoma are usually sup gland

-Rapid-washout parathyroid adenoma (seen on early but has washout on delayed)

-False positives=thyroid adenoma (uptake on thyroid scan), thyroid CA (cold on thyroid scan but hot on mibi), parathyroid CA (rare), other primary CA or malignant adenopathy, brown fat

-False negative=small adenoma, rapid washout, parathyroid hyperplasia

-Ultrasound=oval-shaped hypoechoic and hypervascular lesion located posterior to thyroid

-MRI=T1 hypo and STIR hyper; avid enhancement with Gad (Gad not necessary as lesions are bright on STIR); 30% don’t have classic signal characteristics

-4D Parathyroid CT=noncon from hyoid to clavicles (hypodense to thyroid)à25s post-contrast from angle of mandible to carina (early avid enhancement)à80s delayed (early washout); may see polar feeding vessels (characteristic) in 2/3rd of cases which helps differentiate from LN or thyroid nodule; cannot differentiate thyroid nodule from intra-thyroidal parathyroid adenoma

 

PERITONEAL

SCINTIGRAPHY

Tc-SC or Tc-MAA 5mCi (in small 5cc volume)

Intra-peritoneal

● Need access to peritoneal cavity (via pre-existing catheter or have IR place a percutaneous paracentesis catheter)

● Need Nephrology nurse if accessing PD catheter

PLEURO-PERITONEAL COMMUNICATION:

-Sterile injection of 5mCi Tc-SC (in 5cc volume) via peritoneal catheter and flush with sterile NS (higher volume if small ascites)

-Have patient roll side-to-side and place in trendelenburg for 15min

-Static imaging over chest/abdomen at q15-30min for 1-2hr (may do up to 4hr delayed)

-Transdiaphragmatic extension of peritoneal activity into unilateral hemithorax is diagnostic for pleuro-peritoneal communication or hepatic hydrothorax

 

PERITONEOVENOUS SHUNT PATENCY:

-LaVeen or Denver shunts

-Has one-way valve which allows drainage of ascites into jugular vein to SVC

-Obstruction may be due to valve malfunction or obstructed tube or venous thrombosis

-Sterile injection of  5mCi Tc-MAA (in 5cc volume) into peritoneum and flush with sterile NS

-Static imaging over chest/abdomen at 15, 30, 45, and 60min (may do delayed up to 2-4hr)

-Peritoneum (afferent) à across dia à SVC (efferent)

-Normal visualization of lungs within 30-60min (visualization of liver if Tc-SC is used)

-False positive with CHF and elevated R heart pressures

 

CAPD DIALYSATE LEAKAGE:

-Continuous ambulatory peritoneal dialysis (CAPD)

-Dialysate fluid can leak or collect into abnormal sites like hernias (ventral/inguinal/pericatheter) or pleural cavity which leads to significant fluid retention and reduction in peritoneal ultra-filtration

-Need Nephrology nurse

-Sterile injection of 5mCi Tc-SC into dialysate bag (2.0-2.5L) and gently mix

-Nephrology nurse to instill dialysate via percutaneous PD catheter over 10-15min (record volume instilled)

-Have patient roll side-to-side

-Static imaging 30min, 1hr, and 2hr over abd/pelv (may do delayed up to 3-4hr)

-Nurse to remove ultrafiltrate and record volume and compare with amount instilled

 

PET/CT

F-18 FDG

8-15mCi IV (use 8-10mCi for brain or myocardial study)

 

 

F-18 FDG 0.10-0.14 mCi/kg for peds (min 1mCi)

 

 

NaF-18

5-10mCi IV (PET bone scan)

0.06mCi/kg peds

 

 

 

 

 

 

WHEN TO SCHEDULE PET

-1wk after biopsy

-4-6wks after surgery

-2-4wks (at least 10d) after last chemo

-3mos after XRT

->5d after GCSF (marrow stim drugs)

 

GENERAL PREP INSTRUCTIONS

-NPO x4hrs (if DM) or x6hrs (non-DM)

-Only non-flavored water ok; no chewing gum/mints/candy/cough drops

-Low carbohydrate diet (avoid bread/pasta/rice/potatoes or sweets) x24hrs

-No insulin x4hrs before exam (most oral hypoglycemic medication are ok)

-Keep well hydrated

-Wear warm clothes in winter months (to avoid brown fat)

-Avoid strenuous exercise x24hrs

-For peds patients, need accurate weight to determine dose

-For inpatients, make sure patient is not on tube feeds or TPN or getting IV hydration with dextrose/lactose x4-6hrs

 

INSULIN

-No insulin x4hrs before exam (most oral hypoglycemic medication are ok; consider stopping metformin day of exam and restarting 2d after exam if IV contrast given)

-RAPID/SHORT ACTING REG INSULIN (eat breakfast at 6am and take insulin if neededàthen NPO and no insulinàschedule for PET around 12-1pm)

-LONG/INTERMEDIATE ACTING BEDTIME INSULIN (NPO overnightàschedule for PET in morning by 8AM)

-INSULIN PUMP (put pump on basal rate aka lowest/nightly rate overnight and NPOàschedule for PET in morning by 8amàadjust pump after imaging is over)

 

-Rapid/short-acting insulin=lispro (Humalog), aspart (novolog), glulisine (apidra), regular (R or novolin), velosulin (insulin pump)

-Intermediate/long-acting insulin= NPH (intermediate), basalgar, lantus, toujeo, levemir, degludec (tresiba)

 

IV CONTRAST

-No IV contrast for brain PET for dementia/seizure

-Prefer serum Cr (<1.5) and GFR (>40) (contrast is ok for patient on dialysis)

-Check Cr if: ≥60yo, renal dz (including single kidney, renal transplant), DM, HTN treated with meds, on Metformin (can lead to lactic acidosis if develop renal failure)

-Cr within 30d ok if outpatient and stable

-80-100cc IV water-soluble contrast at 2cc/s via 22-20G or better catheter (1cc/lb for peds) with 55s delay

-For H/N case: 80cc with 55s delay for skull base to thighs followed by 40cc with 30s delay for dedicated H/N

-Consider using Visipaque (isoosmolar) for pts with renal insuff; diabetics; peds; contrast allergy (use 70cc only)

-Consider holding Metformin day of exam and restart 2d after exam (risk of lactic acidosis if develop acute renal failure)

-Contrast induced nephropathy (AKIN criteria): occurs within 48hrs; Cr increases by 0.3 absolute or by 50%; decrease in UOP 0.5cc/kg/hr for at least 6hrs

 

ORAL CONTRAST

-2hr GASTROGRAFFIN PREP (starting 2hr before appointment, dilute 30cc Gastrograffin in 1L or 32oz plain unflavored wateràdrink 500cc slowly over first houràdrink 500cc slowly over next hour)

-ALTERNATIVE: 1hr VOLUMEN PREP FOR SB PATHOLOGY (starting 1hr before appointment, drink 1 bottle of volumen over 1st 20minà drink 2nd bottle over next 20minàdrink 3rd bottle over last 20min)  

-For gastric malignancy, give 1cup of water on CT table prior to imaging to distend stomach and to decrease physiologic uptake

 

SEDATION

-Perform just prior to scanning ~45min after injection

 

CLAUSTROPHOBIA

-Give 30min prior to inj for non-brain PET

     -0.5-2.0mg Ativan PO x1

     -0.25-0.5mg Xanax PO x1

     -2-5mg Valium IV x1

 

BROWN FAT

-20mg Propranalol PO 1hr prior to inj

-1ug/kg Fentanyl IV for peds

 

 

BREASTFEEDING

-pump and dump milk for 8hr after IV contrast

-also avoid holding baby for 8hrs b/c of potential exposure to baby from physiologic uptake within breast tissue

 

QUESTIONNAIRE

-Are you diabetic?

-Allergy to contrast dye?

-Pregnancy or Breastfeeding?

-Time of last meal?

-Type of cancer and location?

-List surgery type and date?

-Last chemotherapy?

-Last radiation therapy?

-Any BM stimulators (Procrit, Epogenor, Aransep)?

-Any pain or recent trauma?

-Last PET scan?

 

**Special prep for myocardial PET and NaF PET bone scan (see next column)

 

 

 

 

 

 

 

 

 

 

F-18 FDG:

-Positron emitter (B+)

-Energy=511keV (1.4 times I-131)

-Range=0.6mm mean and 2.4mm max

-T1/2=110min

-HVL of lead is 6mm (0.3mm for Tc)

-Lead apron has 0.5mm lead (good for xray but need 2 lead aprons to reduce exposure from Tc-99m by 90% aka TVL of 0.8mm)

-Dose rate=4.5-8.5mR/h at 1m (for 8-15mCi) while 6mR/h at 1m for 30mCi I-131

-GLUT1 transporter à HK2 phosphorylates to trap inside cell à does not undergo glycolysis

-Tech can perform 10,000 PET scans/yr before reaching 5rem annual dose limit  

 

● Reschedule patient if:

-recent meal <4hrs

-recent insulin <4hrs

-FBG>200mg/dL (>11mmol/L) diabetic or FBG>150 non-diabetic

-critical value FBG <40 or >400 call M.D.

● If elevated FBG>200, may consider giving short-acting insulin 2-6U (1U drops FBP by ~20; 180-216=2U; 217-252=3U; >252=4-6U)àwait 90minàif FBG<200 injection FDG (o/w reschedule patient)à do PET/CT and recheck FBG at end of exam to ensure no hypoglycemia

● Limit 140cc for IV contrast (max 300cc in 24hrs from all sources including IR procedure and cardiac cath)

● PO F-18 may be given if absolutely cant establish IV access à 60min uptake for oncology PET and 90min for brain PET

 

 

CONTRAST ALLERGY

-Premedication ineffective if performed <4-6hrs

-ORAL PREMEDICATION (50mg Benadryl PO 1hr before; Prednisone 50mg PO 13hr/7hr/1hr before)

 -ALTERNATIVE: IV PREMEDICATION (50mg Benadryl IV/IM 1hr before; Hydrocortisone or equivalent 200mg IV q4hrs until study with at least 1 dose given)

 

RENAL INSUFF

-Avoid IV contrast if GFR<40

-1cc/kg/hr NS (~100cc/hr) for 12hr before and 12hr after exam

-600mg (3cc) Mucomyst PO BID (with water) day before studyàgive a dose right after CT and last dose 12hrs after CT (basically 2doses before and 2doses after CT)ßbenefit of Mucomyst in not proven!

-Alternative: 50mg/kg IV over 4hrs or 150mg/kg IV over 30min

 

CT PARAMETERS

-DIAGNOSTIC (80mAs peds; 150-200mAs thin adult; 200-250mAs standard adult; 250-300 BMI 25-29; 300-400 BMI≥30)
-LOW DOSE NON-CON CT (30mAs peds; 50mAs thin adult; 80mAs standard adult; 100-150mAs obese)

 

 

 

Standard PET

-Eyes to thighs (with arms up)

-Include brain for head/neck malignancy or known history of brain/scalp lesion (with arms down)

-Inject contralateral arm in breast CA patients and ensure entire breast included in FOV

-For pancreatic CA, prefer BG<130

-For gyn or pelvic malignancies, scan PET from pelvis up as usual (to avoid excessive bladder activity)

-For bladder CA, don’t have patient void prior to imaging

-For thyroid CA, prefer Thyrogen prep

-Dual-time point imaging may be useful for thorax (~1.5-2hr after injection)

 

Whole body PET

-Head to toe (with arms down)

-Indications: myeloma, melanoma, sarcoma, skin malignancy

 

Myocardial PET viability**

-Make sure patient has recent MPS for comparison (if not, need high-dose gated resting MPS before exam)

-S/S 93%/58% (Thallium=86%/59%)

-NPO x6hrs

-Glucose-loading protocol (PO 25-50g glucose vs IV 13-25g 50% dextrose with 20mg hydrocortisone)

-PO protocol: FBG<125 give 50g glucose PO; FBG 125-225=give 25g PO; FBG>225=no glucose

-IV protocol: FBG<125=give 25g 50% dextrose IV (over 15min); FBG 125-225=give 13g IV; FBG>225=no dextrose

-Check FBG q15-30min along with vitals

-Give short-acting insulin aspart (Novolog) IV per sliding scale until FBG≤150

-When FBG≤150 à inject 10mCi FDG IV

-Wait 60min before imaging

-Obtain cardiac PET/CT in 1 bed position from carina to below dia (10min) without EKG gating

-Check FBG before letting pt go (make sure FBG>60)

-Recon data in same projections as MPS

-Look for perfusion defect with normal or increased FDG uptake “perfusion-metabolism” mismatch (≥30% LV viability is considered significant)

-Other possibilities include: partial viability and no viability (transmural vs non-transmural infarct)

 

Myocardial PET sarcoid**

-Make sure patient has recent stress/rest MPS for comparison

-High-fat/High-protein/Low-carb diet (eat fried meat/vegetable diet with water but no sugars/sweets or pasta/bread/rice/tortilla/potatoes or soda/juice/coffee or tea with sugar/sweetner) day before exam

-Prolonged fasting x12hrs (important)

-Non-diabetic=NPO after 8pm and schedule for next day 8am exam

-Diabetic=may eat chicken/bacon/sausage for breakfast and take insulin if need at 6am; schedule exam at 12pm

-Optional: 50U/kg nonfractionated Heparin IV 15min before exam (to increase plasma free fatty acids)

-90min uptake before imaging

-Image entire chest

-Recon heart in same projections as MPS (short and long axis)

-Compare to recent MPS

-Characterize LV myocardial uptake as:

no uptake; diffuse uptake, or focal uptake (only focal uptake is considered positive for active inflammatory sarcoid lesion)

-Perfusion-metabolism mismatch:

  1. normal P and no M=normal

  2. normal P and focal increased M=early 

       stage

  3. decreased P and focal increased M=

       advanced  stage

  4. decreased P and no M=end stage  

      (fibrosis)

-Homogenous diffuse myocardial uptake on PET=issues with prep (improper suppression of myocardial glucose uptake)

-Diffuse or focally increased FDG within lateral wall is a common normal variant

-Most commonly involved is mid and basal anteroseptal wall

-Good NPV such that negative PET rules out cardiac sarcoid (MRI more specific than positive PET scan)

 

NaF PET bone scan (whole body)**

-Don’t need FBG before injection

-Only patient prep is adequate hydration before exam (no fasting needed and insulin is ok)

-60min uptake before imaging (90min if renal failure or on dialysis)

-Non-con low dose CT (120kV and 80mA)—recon in ST and bone windows

-Have patient walk around during uptake period to increase activity in lower ext

-Perform WB with arms down

-For combined study give NaF (1x) + FDG (4x) dose

-Overall radiation dose is about 4times that of bone scan

-Compared to BS: higher specificity/sensitivity; higher resolution; better for detecting lytic lesions;  overall higher accuracy

-Consider doing PET first to QC images before doing CT

-Ga-68 PSMA PET/CT is more sensitive for bone mets

 

Ga-68 PSMA PET/CT (prostate CA)

-0.05mCi/kg IV

-20mg Lasix IV at time of radiotracer injection to improve target-to-background by promoting diuresis

-Some give negative contrast via rectal tube (100-150ml water)

-Wait 60min before imaging

-Scan PET from bottom up to reduce artifact from bladder filling

-Indication: Staging of high-risk CA; Prostate recurrence detection even with low PSA (58% detection rate for PSA 0.2-0.5 and 73% detection rate for PSA 0.5-1.0)

-Superior to bone scan or NaF PET for bone met detection (not sensitive for liver mets)

-Unclear usefulness for treatment monitoring or surveillance

-8% of patients with prostate CA do not show over-expression of PSMA leading for false negative exam

-Normal uptake: lacrimal, parotid/submandibular glands, spleen>liver, SB/colon, kidneys/bladder (change SUV threshold to increase detection of small mets around bladder)

-Some non-prostate primary CA can have high PSMA (like colon, breast, renal, GBM, thyroid, lung, HCC)—if suspect visceral metastasis, get biopsy confirmation

-Some b9 lesions have uptake: TB/sarcoidosis, thyroid adenoma, Paget’s, schwannoma, adrenal adenoma, splenic sarcoid

-Celiac ganglion has normal uptake (seen as teardrop uptake medial to left adrenal gland)

 

F-18 Flucicclovine PET (prostate CA)

-Axumin (by Blue Earth Diagnostics)

-Amino acid transport

-FDA-approved 2016 for suspected recurrent prostate CA based on elevated

 

PSA levels following prior treatment (to assess location and extent of recurrence)

-Performance affected by PSA level (?prefer PSA 5 or greater)

-10mCi; Image 3-5min post-inj

-Recommend imaging starting from mid thighs up to skull base

-Prep: NPO x4hrs and avoid excessive exercise 1d before

-Uptake highest in liver and pancreas (rapid clearance from pancreas); moderate in BM, salivary glands, lymphoid tissues, and pituitary; some in myocardium; variable in bowel; minimal in brain

-Skeletal muscle uptake increases with time

-Of note little uptake in bladder or intestine

-<1cm lesion=uptake >BP is suspicious

-≥1cm lesion=uptake ≥BM is suspicious

-Positive scan does not confirm recurrence and Negative scan does not rule out recurrence

-Cannot differentiate btwn CA and BPH (so not good for primary diagnosis)

-Best for patients with biochemical failure and suspected recurrent dz

-Superior to Prostascint scan (Axumin SSA 90/40/74% vs Prostascint SSA 67/57/64% for prostate bed; Axumin 55/97/73% vs Prostascint 10/87/43% for extraprostatic dz)

-Overall detection rate is 68%; PPV 82% for recurrent prostate CA; PPV 72% for prostate/prostate bed; PPV 92% for extraprostatic tumor

-?can detect skeletal mets with Fluciclovine

 

 

Radiation therapy planning PET

-Radiation oncologic personnel to position patient using immobilization device before scanning

-Transfer data to Rad-onc planning workstation 

 

Pediatrics

-Consider bladder cath if not potty trained to avoid rad contamination and artifacts (insert before injection and remove after end of exam)

-Use blanket to keep warm during uptake

-Wrap in sheet to avoid motion during scanning

-May feed (milk) 30min post-injection (if no sedation planned)

-Arrange for sedation (perform just prior to scanning ~45min after injection)

-Low dose CT (80kVp and 30mAs)

-WB imaging for Neuroblastoma and sarcoma

-Normal to have extensive BM uptake than adult (abnl if uptake > than liver)

-Higher uptake in waldeyers ring (peaks at age 6-8yo), adenoids/tonsils, thymus, brown fat

 

Infection

-FUO

-Granulomatous disease (TB/fungal, sarcoidosis)

-Vasculitis (medium to large vessel)

-Vertebral OM (MRI>PET>Gallium; PET better than MRI for followup—uptake confined to margins of destroyed disk after tx does not indicate persistent infx; PET cannot differentiate btwn vert OM or tumor)

-CNS Toxo vs Lymphoma (Thallium preferred)

 

Pregnancy

-Avoid unless absolutely necessary

-Obtain informed consent

-Reduce dose 5-9mCi

-IV hydration àplace foley àgive 20mg Lasix

-If no foley, make sure patient voids at least 4 times during uptake and also after imaging is complete

-F-18 FDG crosses placenta and accumulate in fetus

-Fetal dose exposure 1.1-2.4mGy (varies by trimester)

 

ONCOLOGY PET INTERPRETATION TIPS:

-PET spatial resolution is ~5mm

-Lesion >2cm is usually not affected by volume averaging

-SUV change of 30% is considered significant (for solid tumor SUV reduction by 30-35% is minor response and >60% is major response; for neoadjuvant therapy a decrease in SUV at least 35% suggests responders and >50% compared to baseline has good prognosis)

-Any residual activity 6mos after XRT is suspicious for recurrence

-For SPN, NPV of PET is higher than PPV

-PET is useful for SPN evaluation if low to moderate pre-test probability of CA

-SPN <1cm with uptake > than mediastinum is suspicious while SPN >1cm with uptake < than mediastinum is probably b9 and can be followed with CT (caveat: BAC, typical carcinoid, mucinous CA)

-Baseline PET important for solid tumors and low-FDG-avid lymphoma

-Caution with false positive interim PET (higher NPV than PPV)

-Mixed response generally not seen with lymphoma Rather seen with solid tumors)

-For MRU, consider short-term follow up PET in 6wk-3mos

-There can be lag in response to therapy for extra-nodal disease in lymphoma

 

 

PET/CT

BRAIN (FDG)

F-18 FDG

5-10mCi IV

-Avoid caffeine, alcohol, and drugs before exam

-Decreased sensitivity with steroids, sedatives, and anticonvulsants

-Patient should be seizure free x24hrs

-If needed, sedation should be performed 30min after injection

-Indications: dementia (MCI), seizure, tumor

 

-Ask patient to keep awake with eyes and ears open during uptake period

-30-40min uptake period

-Tuck chin in and secure head for imaging

-Make sure no head tilt

-For seizure (inter-ictal) study, some suggest EEG monitoring starting 2hr before injection and continuing just before imaging to avoid ictal or post-ictal imaging

-QC images for any misregistration artifact before letting patient go

-Normal uptake deep gray matter > cerebrum (gray) > cerebellum (gray) > brainstem

-CT generally done without IV contrast unless imaging for tumor

 

DEMENTIA:

-Inspect imaging in gray scaleàif normal use color scale like rainbowàif abnormal use quantitative analysis

-3D SSP statistical mapping (z-score -1.65 or -2.0 SD below mean is significant)

-Higher sensitivity with MMSE score<20 (moderate dementia)

-FDG PET S/S=96%/90% (accuracy 93%) for AD
-AD=medial temporal lobe (nonspecific) àearly posterior cingulate, precuneus

àposterior parietal association cortexà posterior/lateral temporalàprefrontal

-DLB (and PD)=occipital hypometabolism (medial>lateral) plus areas involved with AD including posterior cingulate gyrus (with less sparing of medial temporal lobe)

-DaT scan help distinguish DLB from AD

-FTD=prefrontal and  anterior/medial temporal hypometabolism (often asymmetric and may only have unilateral frontal involvement); usually don’t involve posterior cingulate gyrus until later in disease

-Multi-infarct dementia (multiple discrete macroangiopathic infarcts; may involve sensorimotor cortex, BG,  or cerebellum) or Vascular dementia (subcortical ischemia due to microangiopathic dz)

-PD (parkinson’s)=frontotemporoparietal hypometabolism contralateral to most affected side (lentiform nucleus activity is preserved in typical PD but not in atypical PD like PSP, CBD, MSA)

-PSP (progressive supranuclear palsy; vertical gaze deficit; humming bird midbrain on sag MRI)=symmetric prefrontal, motor cortex, and midbrain hypometabolism

-CBD (corticobasal degeneration; alien limb syndrome)=unilateral sensorimotor and BG/thalamic hypometabolism (contralateral to most affected side)

-MSA (multiple system atrophy; hot cross buns pons on MRI)=low uptake in striatum (caudate/putamen) and cerebellum

-PCA (posterior cortical atrophy; variant of AD; complex visual processing deficit)= posterior parietal and occipital hypometabolism (lateral>medial)

-HD (huntington’s disease)=low uptake in caudate then lentiform nucleus (especially putamen) and later diffuse cortical hypometabolism

-Cerebellar degeneration=bilateral cerebellar hypometabolism

-Depression, psychiatric d/o, and substance abuse=usually frontal and temporal hypometabolism (mimics frontotemporal dementia)

-Normal aging=decreased frontal and medial temporal hypometabolism

 

ADDITIONAL DEMENTIA INFO:

-Beta amyloid plaques and neurofibrillary tangles in Alzheimer’s dz in ≥65yo

-Younger patients with genetic predisposition for AD have more hypometabolism than elderly (sporadic=E4 allele of Apolipoprotein E or Apoe4)

-NIA/AA categories: Unlikely AD; Possible AD; Probable AD; Definite AD (path-proven)

-Biomarkers:

AD= B-amyloid (CSF beta-amyloid 4 is decreased) and neuronal damage (CSF Tau is increased)

DLB and PD=A-synuclein (both have loss of striatal dopamine; DLB also has amyloid plaques)

FTD=Tau

-DLB presents with fluctuating cognition; gait disturbance (like PD); visual hallucination  

-DLB distinguished from PD by presentation of dementia before or within 1yr of onset of mvmt disorder

-DLB have beta-amyloid plaques like AD (positive amyloid imaging) and decreased striatal dopamine like PD (positive DaT scan)

-FTD is usually seen in younger pts (<60yo) than AD or DLB

-4 subtypes of FTD:

1. Behavioral variant (atrophy of frontal and anterior temporal lobes; frontal hypometabolism)

2. Semantic dementia or progressive fluent aphasia (atrophy of L>R ant temporal lobes aka Broca’s)

3. PNFA progressive non-fluent aphasia (atrophy of left perisylvian region involving insula)

4. Motor syndromes

a) Motor neuron disease

b) CBD or alien limb syndrome (asymmetric frontoparietal atrophy)

c) PSP (profound midbrain atrophy= hummingbird appearance on sagittal MRI)

-FTD ddx include depression, schizophrenia, and cocaine abuse

-MSA (multiple system atrophy) is atypical PD with “hot-cross bun” sign of pons on T2 MRI

 

SEIZURE:

-Interictal FDG PET better than interictal SPECT due to more pronounced hypometabolism than hypoperfusion

-Regional hypometabolism is useful for lateralizing seizure focus (but less reliable for precise localizing focus)

-Difference of 15% btwn suspected focus and contralateral brain on PET is significant

-May see ipsi thalamic hypometabolism

-Cerebellar diaschisis is mainly seen with frontal/parietal focus

-Bilateral temporal hypometabolism predicts poor outcome after surgery

-Bilateral cerebellar hypometabolism is seen with chronic anti-epileptic therapy

-Focal subcortical heterotopia can have decreased/normal/increased uptake in kids

-Extratemporal seizure focus harder to localize (brief activation but rapid propagation); may have subcortical activation in 80% (i.e. ipsi BG hyperperfusion)

 

TUMOR:

-Consider dual time point imaging (wait 3hrs for delayed)

-Tumor:WM ratio <1.5 is low-grade; >1.5 is high-grade

-Glioma grading:

0=no uptake & 1=≤WM (85% grade I or II)

2=lesion >WM but ≤cortex & 3=≥cortex (94% grade III and IV)

-Tumor vs XRT necrosis: uptake greater than cortex is more S/S (than uptake greater than WM) ßcorrelate with Tl-201

-Tumor vs abscess: do In-111 WBC

-Not sensitive for small mets at gray-white matter junction (MRI w/ gad better)

-With malignant tumor there can be a wide rim of surrounding hypometabolism (can be due to edema and/or functional inactivation by infiltrating tissue); also there can be decreased metabolism in contralateral cerebral cortex and cerebellum (degree of decrease correlates with tumor size) which can in part be due to steroid therapy

-Increased uptake in GBM, medulloblastoma, primary CNS lymphoma, pit adenoma, PNET; variable uptake in mets, oligodendroglioma, meningioma; low-grade glioma may not have uptake

 

PET/CT
BRAIN (AMYLOID)

F-18

Florbetapir (Amyvid) 10mCi

 

F-18

Flumetamol (Vizamyl GE) 5mCi

 

F-18

Florbetaben (Neuraceq) 8mCi

● Study should be ordered by Dementia expert (usually Neurologist)

● Need a guardian to accompany patient if memory loss

● If needed, sedation should be performed after inj (right before imaging)

● No meds need to be held

● Make sure recent MRI or CT available to assess for level of atrophy and any encephalomalacia

● Avoid long catheter for IV injection (tracer may adhere to catheter)

● Inspect dose syringe prior to injection to make sure there is no discoloration of solution or obvious particulate matter (otherwise don’t inject)

● Slow injection (over 40s) + 10cc NS flush

● Uptake time: Amyvid 30-50min, Vizamyl 90min, Neuraceq 45-130min

● Acquisition time (1bed position): Amyvid 10min, Vizamyl 20min, Neuraceq 20min

● Look at individual package inserts for potential adverse rxn (like flushing, SOB, chest pressure, increased BP, headache, nausea, dizziness etc)

● Avoid extreme neck flexion/extension

● Effective dose is 4-7mSV

● May need to repeat scan if motion artifact

 

INDICATION:

● Cognitive complaint with objectively confirmed impairment;

● Alzheimer's disease as a possible diagnosis, but when the diagnosis is uncertain after a comprehensive evaluation by a dementia expert; and

● When knowledge of the presence or absence of beta-amyloid pathology is expected to increase diagnostic certainty and alter management

● Persistent or progressive unexplained MCI

● Meets clinical criteria for “Possible AD”

● Atypical early age of onset (≤65yo) of progressive dementia

● Not indicated in asymptomatic patient

● Cannot differentiate btwn AD or DLB

 

INTERPRETATION:

● Align sagittal to AC-PC line and make sure no tilt on coronal view

● Grayscale is recommended by Amyvid (Rainbow is recommended by Vizamyl)

● Adjust brightness on cerebellar white matter (for Vizamyl, set pons intensity to 90% of max i.e. red color)

● Look at CT for degree of cerebral atrophy (significant atrophy may lead to false negative; striatum is least affected by atrophy but involvement is variable—i.e. may not be involved in a positive study)

● Physiologic high WM uptake especially within brainstem, cerebellar white matter, and thalamus (cerebellar WM differentiation is maintained even in an advanced case)

● Inspect following areas:

-Inferior frontal lobes (axial; optional sagittal)

-Posterior cingulate and precuneus (sagittal; optional coronal)

-Inferolateral parietal (coronal; optional axial); superior parietal is more affected by atrophy

-Lateral temporal (axial; optional coronal)ßhighly variable

-Striatum (axial; optional sagittal)ßhighly variable; may not be involved in pos cases; but less affected by atrophy

● Midsagittal slices are particularly useful for assessing orbitofrontal cortex, posterior cingulate gyrus, and precuneus

● Don’t get biased by history

● At least 1 cortical region involvement is needed (early involvement of frontal lobes à cingulate/precuneus)

 

 

● NEGATIVE SCAN

-Negative amyloid scan (indicates sparse to no amyloid neuritic plaques)ßnegative study does not exclude future development of amyloid plaques

-GW differentiation maintained (more activity in WM than adj gray matter)

-Concave WM tracks “fingers”

-Normal for base of frontal and temporal lobes to be less delineated

-Normal uptake seen within salivary glands, parotids, clivus

-Clear gap between 2 cerebral hemispheres (interhemisphere) is wide and irregular 

 

● EQUIVOCAL/INDETERMINATE

-Especially if severe atrophy or motion artifact

 

● POSITIVE SCAN

-Positive amyloid scan (indicates moderate to frequent amyloid neuritic plaques) involving [sites]

-Use cerebellum as control since its GW differentiate is preserved even in abnormal cases

-Don’t get fooled by cortical atrophy or infarct/encephalomalacia

-Frontal cortex most commonly involved followed by precuneus and posterior cingulate

-Sparing of sensorimotor cortices and occipital cortex (also usually absent from medial temporal lobe)

-Gap between 2 cerebral hemispheres is not well defined (may appear as thin regular line)--activity extends to cortical margins and also extends to midline (along interhemispheric fissure) at level of centrum semiovale

-Increased uptake within striatum can be seen in patients with hereditary forms of AD

-Fusion with MRI may be useful in difficult cases

-Semiquantitative assessment (parametric SUVR images) may be useful

 

 

BOTTOMLINE:

● Positive scan by itself does not establish diagnosis of AD (ddx: AD, non-AD forms of dementia like DLB, and normal adults without cognitive impairment)—helps confirm diagnosis of AD only if clinical criteria is met

● Negative scan is more useful (inconsistent with diagnosis of AD at time of imaging)—need to assess for non-AD dementia like FTD etc

● Almost all pts (>90%) with AD will have positive scan (but degree of binding does not correlate with severity of dementia unlike MCI)

● May not predict progression of MCI to AD

 

RENAL SCAN

Tc-MAG3

10mCi IV

 

Lasix

20-40mg

slow IV over 1min (peds 1mg/kg)

 

 

Captopril

50mg PO (crushed in 4oz water) 1hr before

 

 

Enilaprilat/ Vasotec 0.04mg/kg (max 2.5mg) slow IV 15min before

Renal Scan

-Have patient drink 20oz (~500cc) water 2hr before injection

-Ask if patient has sulfa drug allergy (Lasix may be contraindicated if severe allergy)

 

 

Captopril scan (2 day protocol)

-NPO x 4hrs

-Have patient drink 20oz water 2hr before scan

-Get patients medication list (hold ACE-I “-pril” and ARBs “-sartan” meds x3days) ßmay substitute with beta-blockers

-Aceon (perindopril), Accupril, Altace (ramipril), Atacand (candesartan), Avepro (irbesartan), Capoten (captropril), Capozide, Cozaar (losartan), Diovan (valsartan), Lexxel, Lotensil, Lotensin (benazepril), Lotrel, Mavik (trandolapril), Micardis (telmisartan), Monopril (fosinopril), Prinivil, Tarka, Teveten (eprosartan), Uniretic, Univasc, Vaseretic, Vasotec (enlapril), Zestoretic, Zestoretic, or Zestril

-Cr≥1.7 precludes diagnostic study

-Don’t do study if SBP ≤120mmHg (risk of hypotension)

-Lasix not given

 

-MAG3 via tubular secretion; similar to PAH or OIH (Hippuran)

-DTPA via GFR; similar to Inulin

 

 

RENAL SCAN WITH LASIX (F+0 protocol)

-MAG3 preferred over DTPA b/c higher extraction fraction (2x that of DTPA) and tubular secretion (affected less by renal insufficiency than GFR)

-Rapid IV bolus of radiotracer followed by NS flush

-Administer Lasix within 1min of radiotracer injection aka F+0 protocol (most institutions injection at 20min post-injection aka F+20 protocol)

-Dynamic posterior imaging x30min at 1min/fr (after 1min flow at 1s/fr)

-Static Pre-void and Post-void x1 min (to include bladder)

-Also, static imaging of injection site x 1min (to exclude extravasation)

-Existing foley is kept unclamped and allowed to drain to gravity

-Any nephrostomy tube is also kept unclamped (unless requested otherwise by clinician)

 

QUANTITATIVE PARAMETERS:

● Q.C.:

-Delayed clearance of background (extravasation, dehydration, and vascular insufficiency)

 

● FLOW:

-Renal flow detected 2-3s after aorta (or same time as CIA)

-MAG3 flow curve peaks and plateaus

-DTPA flow curve peaks and decreases

● CORTICAL EXTRACTION/EXCRETION:

-Differential function (@2min for MAG3 and @3min for DTPA)=normal 50/50 to 58/42 (abnormal ≥60/40) ß15% used as cutoff for salvageable kidney

-For differential fxn of ectopic kidney, consider DMSA scan instead

-Cortical time to peak activity=3-5min (using cortical ROI)

-Cortical transit time (time till appearance of collecting system activity)=6-8min (using cortical ROI)

-20min %max cortical activity remaining or RCA at 20min= <30% or <0.30 which means 70% of cortical activity gone by 20min (using cortical ROI)

-Progression of renal parenchymal/cortical dysfunction: decreased cortical transit à then also decreased cortical TTP à then also delayed renal flow

-DDX of renal cortical dysfunction: arterial insufficiency (pre-renal); parenchymal dysfunction (renal); obstruction (post-renal)

● COLLECTING SYSTEM CLEARANCE:

-Pre-Lasix T1/2 of peak cortical activity 8-12min (cortical ROI)

-Post-Lasix T1/2 of collecting system activity <10min (normal); 10-20min (equivocal or partial/functional obstruction); >20min (high-grade obstruction)

● POST VOID

- Post-void to pre-void ratio (collecting system) <1

-Residual bladder volume = (post-void counts x urine volume) / (prevoid counts – post-void counts)

-RBV >50ml is abnormal

-RBV >100-150cc may require intervention

● RENAL TIME-ACTIVITY CURVE GRADE
-0 (normal)=prompt rise to peak and washout

-1=Mild delayed rise to peak with preserved washout

-2=Moderately delayed rise to peak and decreased washout (dilated but unobstructed collecting system)

-3=Slow gradual rise without reaching peak activity or slow gradual rise to plateau with no washout (persistent nephrogram)

-4=Renal failure pattern with moderately decreased but measureable uptake (decreased amplitude)

-5=Renal failure pattern with poor uptake (flat renogram with low count plateau)

 

 

CAPTOPRIL SCAN:

-Angiotensinogen (liver) (renin at JGA)à Angiotensin I (ACE from lung inhibited by captopril)à Angiotensin II à vasoconstriction of efferent arterioles to maintain GFR in setting of RAS narrowing afferent arterioles

-Mod to high probability for RAS if abrupt onset sig HTN (DBP>120); young pts; refractory to 3 anti-HTN meds; low K;  abdominal bruit; ≥50% RAS on anatomic imaging with post-stenotic dilatation (press gradient >40mmHg); renal vein sampling (renin ratio of affected:unaffected 1.5:1)

-Positive study suggests hemodynamically significant RAS and predicts improvement with intervention

-2day protocol: post-captopril on day1 and if needed, baseline renal scan (without Lasix) on day2

-Start 22G or better IV and give 250cc NS IV if patient has SBP<140mmHg (may cancel study if SBP <100mmHg)

-Check standing and supine blood pressures before injection

-Give 25-50mg captopril PO (crushed with 250cc water) 1hr before injection

-Alternative: 40ug/kg (max2.5mg) Vasotec or Enalaprilat IV 15min before injection

-Monitor supine blood pressure q15min (to look for hypotension)ßNotify MD if SBP drops below 120mmHg (elevate legs or trendelenburg and give 500cc NS IV)

-Rapid IV bolus of radiotracer

-Dynamic posterior imaging x30min (after 1min flow)

-Static imaging of injection site to exclude extravasation

-Process study with both whole renal and cortical ROIs

 

ANALYSIS OF CAPTOPRIL SCAN:

HIGH PROB (>90%)

-Renogram curve (most specific): grade change ≥1 for cortical ROI or change ≥2 for whole ROI

-Time to peak: increase by at least 2min or 40% ßchange from 5min to 7min is more sig than 18min to 20min

-20min/max ratio (RCA 20): change ≥0.15 or 15% (cortical ROI)

-Differential fxn: change≥10% (uncommon by indicates high prob)

LOW PROB (<10%)

-Normal post-ACE scan

-Abnormal baseline but improved post-ACE

INTERMEDIATE PROB (EQUIVOCAL)

-Abnormal baseline and no change post-ACE

-Bilateral symmetric cortical retention (may be due to dehydration, hypotension, renal insufficiency, bilateral obstruction)

 

RENAL TRANSPLANT:

-Need to know: days since transplant; serum cyclosporine level; results of transplant renal ultrasound (rule out vascular issues like RAS, RA occlusion, RVT etc)

-Anterior imaging over pelvis

-Otherwise same protocol as Renal scan (see above)

-Quantitative perfusion (requires tight bolus):

KAR=kidney-aorta ratio (ROI over kidney and distal aorta just above bifurcation; ratio of peak renal counts to aorta counts; normal 0.64-1.16; higher the better); requires tight bolus otherwise not reliable.

Hilson’s PI=perfusion index (ROI over iliac artery and renal; normal<1.5; lower the better

-Visual assessment of renal perfusion: good (kidney≥aorta), fair (<aorta), poor (<<aorta), none (absent)

-Elimination index (K20/3): ratio of counts at 20min to 3min using whole renal ROI with ≤0.8 is normal and >8 is abnl (useful for follow up)

-ATN: uncommon with transplant from living donor than cadaveric; occurs within 1-3days post-tx and usually recovers within 1-2wks; U/S shows swollen kidney with prominent corticomedullary differentiation (bright cortex and dark pyramids); RI>0.8 (non-specific since also seen with rejection); dynamic MRI shows delayed medullary enhancement and impaired contrast excretion; CT also shows persistent nephrograms; MAG3 shows nl flow + persistent nephrogram that stays (DTPA shows nl flow + persistent nephrogram that fades away without ever excreting)

-ATN ddx:

1. Accelerated rejection (cant tell from ATN; within 24hrs to 1wk; may be reversible; more common in pts with previous transplant)

2. Acute rejection (has abnl flow; occurs 1wk to 3mos post-tx; worsens upon f/u; has uptake on Tc-SC like chronic rejection)

3. Cyclosporine toxicity (usually after 1mo; within 2-3d of high dose >300ng/ml; may or may not have normal flow so mimics ATN and acute rejection; quick resolution with dose adjustment)

4. RAS (delayed flow and persistent nephrogram; elevated PSV on ultrasound)

-Chronic rejection= >3mos to many yrs; small kidney with poor fxn; uptake on Tc-SC (like acute rejection)

-RA occlusion=photopenic kidney (absent arterial flow on ultrasound)

-Acute RVT=enlarged kidney with everything delayed (flow/uptake/excretion) and later photopenia (decreased or absent venous flow and possible reversal of diastolic arterial flow on ultrasound)

-Urinoma=initially photopenic defect that fills in on delayed

-Leak=seen on excretory phase

-Lymphocele/seroma=persistent pararenal photopenic defect

 

RN VCUG

(CYSTOGRAPHY)

Tc-SC/DTPA

0.5-1.0mCi

retrograde via foley

● Consider holding last feed for babies and bring milk in bottle

● Peds nurse/tech to place 5-6Fr (<1yo) or 8Fr (>1yo) feeding tube with lidocaine jelly (may collect sample for urinalysis if needed) and drain bladder

● Check results of renal ultrasound (prefer ultrasound to be performed prior to this study)

● Avoid if patient has current UTI or within 2wks of UTI (prefer documented treated UTI)

● Ask about latex allergy

 

● Fluoro VCUG indicated for recurrent “febrile” UTI or 1st febrile UTI with abnormal U/S

● Everyone should get U/S prior to RN-VCUG unless asymptomatic sibling screening

● Indications:

-initial eval of females with UTI

-asymptomatic sibling screening with family history

-assess results of anti-reflux surgery

-serial eval of neurogenic bladder for reflux

● Calculate bladder capacity (in ml)

-<1yo = kg x 7

->1yo = (age + 2) x 30

● Hang 500cc NS bag less than 100cm or 1m above table and drip via gravity to fill bladder (should fill bladder within 10min)

● For potty trained child, position them sitting on bedpan with back against camera and other camera underneath (otherwise supine with camera underneath)

● Continue filling until drip slows/stops or toes curl (may consider slowing instill rate in infants to decrease bladder irritation or spasm)

● For non-potty trained kids keep catheter in during voiding (for potty trained kids, take catheter out once adequate filling is achieved)

● Dynamic posterior imaging at high frame rate (5-10s/fr) throughout filling/voiding cycle à if abnormality seen, consider post-void static image x30s (after changing diaper of cleaning)

● Record

-max volume instilled (before voiding)

-number of bladder fills

-time at which reflux occurred (during filling vs voiding)

-if occurs during filling, report volume instilled at time of reflux

-pre and post-void bladder counts and volume voided to determine post-void residual (other option is image 1cc urine under camera for same time as individual frame)

● Repeat (cyclic) filling may be necessary if kid only partially empties the bladder (in-adequate voiding)

● Bladder dose 100x less than fluoro VCUG

 

INTERPRETATION:

-Grade 1=reflux limited to ureter (equivalent of VCUG grade I)

-Grade 2=activity reaches collecting system (equivalent of VCUG grade II/III)

-Grade 3=grade 2 plus dilated collecting system and dilated tortuous ureter (equivalent of VCUG IV/V)

 

SALIVARY SCAN

TcO4

15mCi IV

● No patient prep

● Supine (Waters projection)

● Dynamic flow (3s/fr) x1min

● Pre-lemon 20min dynamic (1min/fr) à then L/R lateral statics (pre-stimulus to assess uptake)

● Give 3cc lemon juice PO (stimulation)—mouthful of lemon juice and hold it in mouth (and distribute all around) for as long as possible before swallowingàPost-lemon 20min dynamic (1min/fr) à then L/R lateral statics (post-stimulus to assess excretory function)

● Draw ROI over parotids and submandibular gland to create TAC [look at degree of uptake (salivary to thyroid ratio of 1-2:1) , peak accumulation, and clearance of activity]

● Normal trapping begins 1min and peak within 10min

● Normal washout 3min after stimulation

● Acute sialadenitis= increased uptake and retention

● Chronic sialadenitis=decreased/delayed uptake and excretion (similar to Sjogrens)

● Obstructed duct= increased/normal uptake and poor/no excretion

● 50% of warthin’s tumor can have uptake (may be bilateral)

 

SAMARIUM/

STRONTIUM

THERAPY

Sm-153 EDTMP (Quadramet)

1mCi/kg IV slow over 1-2min

 

 

Sr-89 chloride (Metastron)

40-60uCi/kg (~4mCi) IV slow over 1-2min

 

 

● Keep well hydrated

● Recent CBC, WBC diff, and Cr within 1wk

● Recent bone scan within 4months

 

 

 

 

 

 

 

 

 

Samarium-153:

-T1/2=46.3h (~2d)

-Beta (0.8MeV max or 0.3MeV avg)

and Gamma (103keV)

-Range=0.6mm avg

 

Strontium-89:

-T1/2=50.5d (~2mos)

-Beta=1.5MeV max or 0.6MeV avg

-Range=2mm avg

● Sm-153 is delivered frozen on dry iceàthaw to ambient temp (takes about 2hrs; clear colorless without suspended particles) before administration (use within 6hr of thawing)

● Sm-153 has weak gamma so lead syringe protector should be used

● May perform post-therapy scan for Sm-153 6hrs after therapy (103keV +/-20% window)

 

CRITERIA:

● Symptomatic osteoblastic mets (confirmed on bone scan) w/ long-term analgesic use

● Life expectancy >3mos

● Platelets >60k (prefer >100k)

● ANC>1.5 and WBC>3.5

● Prefer Hgb>9 (not a requirement)

● Last chemo >6wks (some have shown  combining w/ chemo yields better relief)

● Uncomplicated bone mets (no current or impending cord compression or impending pathologic fx or hypercalcemia)

● Non-impaired renal fxn (eGFR >30)

● Not pregnant (neg BHCG within 48hrs) and not breastfeeding

 

EXPECTED BONE PAIN PALLIATION:

-70% response rate

-complete pain relief in 20%

-duration of pain relief 3-6mos

-pain flare-up 1st week esp within 3d (pain relief start 7-10d after treatment)

-myelosupression common (nadir 4-6wk)—check CBC q2wk x8wks after treatment

-wait >3mos before re-treatment

 

WRITTEN INSTRUCTIONS:

-Urinary precautions x12-24hrs

-Universal precautions

-Avoid sex x48hrs

-If bladder incontinence, recommend disposable diapers (give gloves)

 

THALLIUM

SCAN (tumor)

Tl-201

4mCi IV

● NPO x 4hrs

● Thyroid cancer patient do not need to d/c synthroid

● Tumor imaging not affected by steroids, chemo/XRT (unlike Gallium)

 

● WB scan 20-60min after injection and 3hr delayed

● Do brain SPECT at 3hrs post injection

 

INTERPRETATION:

● Physiologic uptake: choroid, lacrimal, salivary, thyroid, heart, liver, GB, spleen, renal cortex (critical organ), testes, muscle (more but less well-defined than sestamibi)ßno bladder activity

● Thallium is useful for thyroid CA recurrence with TG ag pos but I-131 neg (if patient cant get FDG PET/CT); less sensitive for bone, lung, or liver mets; also not sensitive for detection of residual thyroid tissue post-thyroidectomy

● Brain tumor recurrence vs XRT/postop (FDG PET is preferred); toxo vs lymphoma (Thallium is toxo neg and lymphoma pos while Gallium is pos for both; lesion to background ratio of 2.5:1 suggests lymphoma over toxo)

● Kaposi sarcoma is Gallium neg but Thallium pos (ddx=lymphoma; pulm infx has lower uptake on Thallium esp delayed imaging)

● Thallium has higher sensitivity for NHL than Gallium (overall Thallium has more uptake in low grade lymphoma than Gallium)

● Normal or hyperplastic/rebound thymus is Gallium pos but Thallium neg

● Thallium is good for primary bone CA for determining extent of involvement and following therapy response b/c not affected by bone healing response (but can have uptake in fracture, OM, pagets, fibrous dysplasia) 

● No uptake within BM so diffuse BM activity suggest hyperplasia (eg anemia) while focal BM suggest CA

 

TESTICULAR

SCAN

TcO4

15mCi IV

● No patient prep

● Usually performed in conjunction with ultrasound

● Penis taped out of FOV

● Legs abducted and feet together in frog-leg position

● Towel under scrotum and over thighs as a sling to bring testicles anterior

● Make sure the testis are not retracted and testis are situated side-by-side not one behind the other

● Minimize source to camera distance

● Dynamic flow 1-2s/fr x 1min, static BP and 15-min delayed static

● Must have patient identify symptomatic side (with one finger) and mark it with cobalt pen

 

INTERPRETATION:

● Normal = symmetric and faint uptake in testis and scrotum (discrete iliac and femoral vessels are seen) 

● Acute torsion (<24hr)=photopenic testis with “nubbin” sign

● Late/missed torsion (>24hr)=“donut” sign (ddx abscess, hematoma)

● Epididymitis/orchitis=focal/diffuse increased flow and delayed uptake due to swelling (ddx tumor)—epididymitis is lateral and orchitis is medial

● Hydrocele=“horseshoe” photopenia around the testis

● False positive: retracted testis; hematoma; abscess; large hydrocele; hernia

● False negative: hyperemia after spontaneous untwisting; retracted testis

 

THYROID UPTAKE/SCAN

I-123

0.2-0.4mCi PO (use 2mCi if assessing for substernal thyroid)

 

I-131

10uCi PO (uptake only)

50uCi PO

(uptake/scan)

 

Tc-pertech.

10mCi IV

(scan only) 0.05mCi/kg prefer for peds

I-123 uptake/scan (2day)

-NPO x2hr before and x2hr after the pill on day1

-Hold PTU or Methimazole/Tapazole x1wk

-Hold multi-vitamins x1wk

-Hold Amiodarone x6months

-No recent iodinated IV contrast in last 4-6wks

-Prefer low-iodine diet x10d

-Ask if patient is breastfeeding

 

I-131 uptake + Tc-pertech scan (2day)

-Need pregnancy test (<60yo without documented hysterectomy)

-Otherwise, same prep as I-123 above

-Urinary precautions only for I-131

-No written directive ≤30uCi I-131

-No written instructions <7mCi I-131

 

Tc-pertech scan only (1day)

-NPO x4hr

-Hold PTU or Methimazole/Tapazole x1wk

-Hold multi-vitamins x1wk

-Hold Amiodarone x6months

-No recent iodinated IV contrast in last 4-6wks

 

Thioamides (anti-thyroid drugs)

-risk of hepatic dysfxn and agranulocytosis which manifests as fever and sore throat

-PTU for pregnant patients and for treating thyroid storm

-both PTU and methimazole/tapazole deplete thyroid hormone store after 1month and affect organification

-PTU also affects peripheral conversion of T4 to T3

-1/3 remission in 2yrs

 

I-123 uptake/scan

-Check labs to ensure TSH is suppressed (normal TSH 0.5-5.0mU/L)

-4hr RAIU (normal 5-15%) and 24hr RAIU (normal 10-30%)  using thyroid probe at 25-30cm

-%RAIU = [(neck-thigh) / (capsule x DF) –room] x100

-Anterior (with/without marker) and 45deg LAO/RAO views

-Pinhole imaging (3-6mm aperature) at 24hr (use parallel hole collimator for marking nodules with cobalt pen to decrease parallax effect seen with pinhole)

-Physical exam to assess gland size (1x=normal; 2x=enlarged on palpation; 3x=visually enlarged)

-Hyperthyroidism etiology:

Graves (+TRAb especially TSI),

Autonomous nodule (T3 toxicosis),

Toxic MNG,

Thyroiditis (elevated TG)

-cold nodule ddx=40% colloid cyst, 40% non-functioning adenoma, up to 20% CA

-Risk of CA in setting of TMNG is 5% and <1% for hyperfunctioning (hot) nodule

-Consider using  2mCi I-123 if assessing for substernal thyroid (don’t need uptake)

-RAIU<5% suggest thyroiditis (btwn 5-10% suggest recovering thyroiditis)

-Homogenous gland with normal RAIU in setting of hyperthyroidism=mild Graves vs Graves with exogenous iodine source vs recovered thyroiditis (TSH trends show improvement)

-Jod basedow (iodine-induced thyrotoxicosis in iodine-deficient areas)

-Wolff Chaikoff effect (paradoxical transient deceased in T4 in normal or Graves pts after iodine load; used to treat thyroid storm in the past)

-Thyroid storm (elderly pts with elevated RAIU, elevated T3, and severe systemic illness; pre-treat with beta blockers and PTU to deplete hormone stores)

-For ectopic thyroid in peds: do 4hr/24hr uptake and 24hr imaging (including lateral projection) with large FOV and pinhole

-Thyroid nodule are rare in kids and high likelihood of malignancy; even hot or autonomous nodule in kids should be excised with lobectomy to assess for CA

 

I-131 uptake + Tc-pertech scan

-Administer 10uCi I-131 POànext day measure 24hr RAIU (skip 4hr)àthen inject 10mCi Tc-pertech IV and wait 20min to image neck (large FOV)

 

Tc-pertech scan only (prefer for peds)

-Indications: pediatrics r/o ectopic thyroid (I-123 preferred to see if organification is preserved); can’t take PO; need same day results; post-partum thyroiditis; confirm cessation of lactation

-Image 20min post injection with parallel hole collimator (large FOV to include salivary glands)

-Quantitative approach: image dose in syringe under camera  x1min (pre-injection)àinject (avoid extravasation and image injection site to confirm)à image residual in syringe under camera x1min (post-injection) à wait 20min and image neck x1min and then do routine views for x5min

-Trapped but not organified

-Uptake = (thyroid – BK) / (pre – post syringe)

-Normal uptake range 0.4-4.5%

-Hot nodule may be discordant nodule (consider I-123 correlation; hot on Tc-pertechnetate and cold on I-123 is suspicious for CA)à5% may be malignant

-Compare thyroid vs salivary gland activity (thyroid activity considerably greater than salivary gland activity in hyperthyroidism)

 

THYROID BLOCKING (radiation protection)

N/A

N/A

● KI (iodide not iodate) is approved for thyroid blocking agent in radiation emergencies by FDA 

● Protects from internal (ingested/inhaled) exposure only (not external exposure)

● Low dose (~100mSv)=stochastic effect (potential thyroid CA)

● High dose (~1000mSv or 1Gy)= deterministic effect (hypothyroidism)

● Need 100mg elemental iodine daily (decreases radioiodine uptake by <1%)

● Radioiodine crosses placenta (into fetus) and also gets into breastmilk (accumulation peaks at 48hrs)

● Fetal thyroid accumulates KI and radioiodine by 10-12wks (so thyroid blocking useless before 10wks gestation)

● Thyroid blocking most important in kids<18yo,  pregnant women (KI crosses placenta so provides protection for both baby and mom)ßfor breastfeeding mom KI only protects mom (baby needs their own KI)

● Start taking KI 6-12hr before (useless if given >6hr after exposure) and continue until 1d after end of exposure

● KI less effective if high dietary intake of iodine (do low iodine diet to let KI be effective)

 

DOSE GUIDELINES FOR KI PILL:

-130mg KI pill contains 100mg of elemental iodine (IOSAT tablet)

-130mg qd for preg mom (protects fetus)

-16mg qd for newborn (<1mo)

-32mg 1mo-3yo

-65mg (half pill of 130mg) 3-12yo

-130mg qd >12-18yo and adults ≤40yo

-For >40yo (nonpregnant and not breastfeeding) may give 130mg qd if predicted dose to thyroid ≥500cGy or 5000mSv

-Treatment priority is peds and pregnant women especially within 50miles radius of event

-Potassium “iodide” (not “iodate”) pill is recommended by FDA

 

ALTERNATIVES TO KI:

-SSKI 1g/cc (take 2drops per day) 0.1cc in cup of water

-Lugol’s solution 2% (2.5mg/drop; 20drops=50mg) vs 5% (6.25mg/drop; 8drops=50mg)

-Both SSKI and Lugol’s are liquid (take with water/juice/ milk/formula)

-1drop=0.05cc

-Iodoral (Lugol’s in pill form) comes in 12.5mg and 50mg tabs

-Potassium perchlorate (PO) or Sodium perchlorate (IV) for pts allergic to iodine or high risk for thyrotoxicosis (400mg tab PO qd for KP or 100mg/d for NaP IV in 4-5 divided doses)ßperchlorate inhibits trapping so releases iodine

  

THYROID

METASCAN

I-123

1-2mCi PO

 

 

I-131

4mCi PO

 

● NPO x2hr before and x2hr after the pill

● Hold Synthroid x4wks and Cytomel x2wks (not needed if on Thyrogen protocol) with documented TSH>30

● Low iodine diet (<50ug/d) x10d (no dairy/milk/eggs/ice-cream/bread/ soy/seafood/iodized salt/sea-salt)

● Hold multi-vitamins x1wk

● No recent iodinated IV contrast x4-6wks

● Need pregnancy test (<60yo without documented hysterectomy) within 24-48hrs of administration

● Hold Amiodarone x6months

● Ask if patient is breastfeeding (prefer I-123 over I-131 if they are)

 

 

What to eat on Low-iodine diet=cook at home (don’t eat out); fresh fruits/vegetable without iodized or sea-salt; cook meat (not fish/seafood) with vegetable oil; salad with unsalted nuts and olive oil; pasta without high iodine ingredients; egg white ok; sodas; black coffee/tea without milk; alcohol

 

 

● Wait 24hr for I-123 and 48-72hr for I-131

● High-energy collimator for I-131

● Consider SPECT/CT for any abnormal uptake

● Plan to treat within 3d after I-131 metascan (per SNM) to avoid stunning

 

 

AU checklist and paperwork

-Review patient history (pathology; prior I-131 therapy; prior metascan; stimulated TG antigen/ab levels with normal <2 and <20 respectively) 

-Make sure TSH>30 (Thyroxine withdrawl or Thyrogen)

-Ensure negative pregnancy test in women

-Written directive completed and signed (for I-131)

-Verify dose is within prescribed range (or within +/-10% for I-131 and within +/-20% for I-123)

-Obtain signed informed consent (for I-131)

-Written instructions required for breastfeeding cessation (≥2uCi I-131)

-No requirement for written instruction for radiation safety isolation (<7mCi I-131)

-Urinary precautions only (some impose light isolation x24hrs if kids or pregnant female at home or work with kids)

 

IMAGING:

-If on Thyrogen protocol, give dose 24hrs after final injection

-WB imaging 24hr after I-123 or 48-72hr after I-131 along with spot views of neck/chest with/without markers

-Give water to troubleshoot any potential esophageal activity

-Consider laxatives if excessive bowel activity especially if patient reports constipation (to reduce colonic exposure)

-Consider treatment within 3d of I-131 metascan to avoid potential stunning (per SNM)

 

INTERPRETATION:

-Physiologic uptake within choroid plexus, salivary glands/nasopharynx, breast, thymus, GI tract including eso(swallowed)/ stomach/colon, kidneys/bladder, skin/scalp (sweat), thyroglossal duct tract

-Diffuse liver uptake is physiologic (metabolizes thyroid hormone) but should prompt close inspection to determine site of iodine-avid residual/recurrent malignancy

-If elevated TG antigen >10 but negative metascan, consider PET/CT (with Thyrogen)

 

THYROID DOSIMETRY

(Max Tolerated Dose)

I-123 2mCi PO

● Same prep as Metascan (but no pregnancy test needed since performed with I-123)

 

INDICATION:

-Diffuse lung micromets (risk of fibrosis)

-Renal insufficiency (decreased renal excretion and higher risk for BM suppression)

-Low BM reserve (abnormal CBC)

-If considering dose >200mCi esp in elderly pts >70yo

 

 

 

SIMPLIFIED PROTOCOL:

● Give 2mCi I-123 P.O. (=ADMINISTERED DOSE) à wait 1hr and without having the patient void bladder perform WB drag (from head to proximal thighs) à Draw WB ROI on anterior and posterior view and calculate GM for "TOTAL COUNTS“ à decay factor (0.299) x TOTAL COUNTS = “DECAY CORRECTED TOTAL COUNTS”

● Have patient return in 24hrs and have them void bladder before imaging à repeat WB drag (use same imaging parameters) à Draw Lung ROI on anterior and posterior views and calculate GM for "LUNG COUNTS" or do same for whole body ROI to get "WB COUNTS" (for Bone Marrow)

● Lung calculation= (LUNG COUNTS / DECAY CORRECTED TOTAL COUNTS) / ADMINISTERED DOSE = X mCi lung retention per 1mCi of radioiodine

● Can do similar WB calculation to determine safe dose to avoid BM suppression

● Then use this info to calculate max tolerable dose so that <80mCi lung retention (for lung mets) or <120mCi WB retention (for BM suppression in pt with renal failure)

● 79mCi x X = Max tolerated dose for lung

● 119mCi x X = Max tolerated dose for BM

  So if you plan to treat with 200mCi, this means 200mCi x X = should be <80mCi for lung mets or <120mCi for BM suppression, otherwise need to lower the dose accordingly

 

REFERENCE:

-WB retention <120mCi at 48hr for BM (<200cGy or <200rad to BM)

-WB retention <80mCi at 48hr for lungs

 

THYROID

THERAPY

Hyperthyroid

12-30mCi PO

 

 

Thyroid

Cancer

75-200mCi PO

(1.0-1.5mCi/ kg for peds)

HYPERTHYROIDISM

-NPO x2hr before and x2hr after tx (encourage hydration to allow elimination)

-Hold PTU or Methimazole/Tapazole x3-5d

-Hold multi-vitamins x1wk (also no topical like betadiene)

-No recent iodinated IV contrast in last 4-6wks (may confirm with 24hr urine iodine excretion study <50ug/24hr)

-Hold Amiodarone x6months

-Prefer low-iodine diet x10d before (50u/d) and continue 24hr after tx

-Ask if patient is breastfeeding (indefinitely d/c 6-8wks before tx; may confirm with TcO4 scan)

-No unprotected intercourse 10d prior to therapy

-Negative serum B-HCG (within 24hrs prior to tx)—unless documented hysterectomy or age≥60yo

-Thyrogen is contraindicated for tx of TMNG

 

 

 

THYROID CANCER

-NPO x2hr before and x2hr after tx (encourage hydration to allow elimination)

-Hold Synthroid x4wk and Cytomel x2wk (not required if Thyrogen

rh-TSH protocol 0.9mg IM x2)

-Hold multi-vitamins x1wk (also no topical like betadiene)

-No recent iodinated IV contrast in last 4-6wks (may confirm with 24hr urine iodine excretion study <50ug/24hr)

-Hold Amiodarone x6months

-Prefer low-iodine diet x10d before (50u/d) and continue 24hr after tx

-Ask if patient is breastfeeding (indefinitely d/c 6-8wks before tx; may confirm with TcO4 scan)

-No unprotected intercourse 10d prior to therapy

-Negative serum B-HCG (within 24hrs prior to tx)ßunless documented hysterectomy or age ≥60yo

-Consider checking CBC and Cr in elderly pts >70yo

 

REQUIRED PAPERWORK

-Written directive by A.U. (verify assayed dose within +/-10% of prescribed)

-Negative serum B-HCG within 24hrs b/f tx (unless documented hysterectomy or age≥60yo)

-Signed informed consent (remind about avoiding pregnancy x6mos)

-Written instructions for radiation safety (isolation for 3d for hyperthyroidism and 5d for cancer)

-Written instructions for indefinitely d/c breastfeeding 6-8wks before tx

-Patient Specific Calculations for outpatient high dose ablation (>33mCi) to ensure general public dose <0.5rem or <5mSv

-Save shipping label (lot #)

-Pocket radiation card (valid for 80d after tx)

 

 

HYPERTHYROIDISM

-Make sure TSH is suppressed

-Calculate dose for Graves=

[25g x size x 0.150mCi/g] / [RAIU/100]

size: 1=normal, 2=enlarged on palpation, 3=visually enlarged

-For Graves use minimum 12mCi

-Consider max dose of 30mCi if: toxic MNG or autonomous nodule; enlarged gland; prior failed therapy; rapid turnover (consider Lithium to improve retention); low RAIU (use Thyrogen except for TMNG and also low-iodine diet); chronic tx with PTU

-Thyroid opthalmopathy (esp seen in smokers with high T3 and TRAb): pre-treat with steroids and gradually taper; consider giving ATD 3d after tx to reduce RAI-induced increase in FT4

-Assess patient social situation to ensure dose to public <0.5rem

-Check TSH 4wks after therapy

-May reduce goiter size by only 30%

-Failure of treatment can be up to 10%

 

THYROID CANCER

-Aggressive variants: hurthle cell variant of Follicular; insular, tall cell, columnar cell, diffuse sclerosing, trabecular solid, poorly-diff variant of Papillary

-Low risk variants: microscopic papillary and encapsulated (not invasive) follicular-variant of papillary

-High risk criteria for recurrence: M1 <45yo; T4 or N1b or M1 for 45yo; Follicular CA with size >4cm; macroscopic invasion; incomplete tumor resection;  TG out-of-proportion to post-therapy WB scan

-Optional: pre-therapy neck uptake should be <6% post-thyroidectomy; uptake 6-20% with star-artifactàdo remnant ablation first; uptake 6-20% without star-artifactàdo high dose therapy; uptake >20% do repeat surgery

-Make sure TSH>30

-Record dose rate in mR/h @1m

-Do inpatient therapy if >221mCi or ≥48.5mR/h or likely exposure of >0.5rem (>5mSv) to member of public or >0.1rem (>1mSv) to pregnant/kids<8yo

-For inpatient, use dose rate <7mR/h for release (some agreement states use <5mR/h)

-Post-ablation WB scan for cancer in 7-10d

-If micromets to lungs, consider pre-tx dosimetric evaluation to ensure WB retention <80mCi at 48hr to avoid pulmonary fibrosis

-In older pts with renal insufficiency consider pre-tx dosimetric evaluation to ensure WB retention <120mCi at 48hr to avoid BM suppression

-Start synthroid 24-48hr after therapy to keep TSH <0.1 (hi risk) or 0.1-0.5 (low risk)

-Follow up with serum TG antigen/ab, neck U/S, and I-131 metascan

-Serum markers post-therapy:

  -basal TG ag should be <1ng/ml and

   TG ab<20

  -stimulated TG ag should be <2-5ng/ml

  -stimulated TG ag ≥10ng/ml is concerning

   on withdrawl and ≥5ng/ml on rhTSH

  -if TG ab positive but TG <2ng/ml is

   considered neg (unless if TG ab  

   increases)

-Macroscopic dz (>1cm) may be better treated with surgery

-Lung macromets or bone mets do not respond well to therapy

-Positive TG ag and neg I-131 metascan, may consider empiric I-131 therapy (also consider FDG PET/CT if TG ag>10 for dedifferentiated CA; FDG PET also good for Hurthle cell CA)

-Bone mets and lung macromets may not respond well to I-131 therapy

-For renal insufficiency, consider reducing dose or get WB suppression (check CBC)

-Remnant ablation dose is 30-100mCi

 

 

KEY RADIATION SAFETY INSTRUCTIONS:

-Home isolation (no hotels) for 3d for hyperthyroidism and 5d for cancer

-Maintain prudent distance (about 3-6feet) from others (especially kids and pregnant women)

-Sleep alone (prefer own room)

-Urinary precautions/hygiene (prefer sole use of a bathroom)

-Keep well hydrated especially 1st 24hrs to facilitate prompt elimination of tracer

-Avoid public places, avoid any travel, avoid prolonged auto ride with others

-Hold any hot trash x1month (avoid generating hot trash in general)

-Avoid pregnancy for 6months

 

RADIATION SAFETY FOR INPATIENTS:

-Radiation safety training for nursing staff (wear TLD; no pregnant staff)

-Radiation sign on door

-Patient in isolation with door closed (not allowed to leave room and no un-authorized entry)

-No visitors (RSO may allow non-pregnant adult visitor for 1hr per day behind 2mR/h line on case-by-case basis)

-No blood draws/labs or routine vitals

-If patient needs nursing care, rotate staff (leave clipboard with several TLD badges for nursing staff) and stay behind 2mR/hr line if possible

-No housekeeping

-Do not remove any linen/trash from room (2 large regular trash bins and 1 large linen bin)

-Low iodine diet on disposable service items like plates/cups etc

-Lemon drops or sour hard candy or cough drops by bedside

-SSKI bottle in toilet (patient to put 5-10 drops in bowl prior to every use and flush twice)

-Phenergan 25mg PO q6h PRN for nausea

-NSAIDs PRN for radiation thyroiditis

-Patient to take showers daily (and wash hair if possible before discharge)

-NM tech to measure exposure at 1m, at door, and across adjoining room wall daily

-Patient released when exposure rate <5-7mR/h at 1m

-Upon patient release, room to stay locked until decontaminated and decayed to background (NM tech will release room in 3-4wks)

 

POTENTIAL SIDE EFFECTS (low dose):

-rare hypersensitivity to iodine (hives etc)

-sore throat (pain/swelling due to radiation thyroiditis)—may result in difficulty swallowing (consider NSAIDs)

-dry mouth, dry eyes

-loss of taste (temporary)

-nausea

-exacerbation of hyperthyroidism sx (palpitations, tremors, etc)

-failed therapy

 

POTENTIAL SIDE EFFECTS (high dose):

-similar to low dose (see above)

-permanent dry mouth (xerostomia) or dry eyes (epiphora)

-dental caries and mucositis (brush teeth often to avoid this)

-radiation sickness (n/v and headache esp with dose>200mCi)

-BM suppression (esp with dose>200mCi; check CBC 1mo after therapy; nadir seen btwn 3-5wks and recovers after 3-5wks)

-transient amenorrhea/oligomenorrhea (no decrease in female fertility)—lasting 4-10mos

-decreased sperm production/fertility (consider sperm banking with cumulative dose >400mCi)

-secondary malignancy (Leukemia, solid tumors)—cumulative dose >500mCi

-lung fibrosis (if diffuse micronodules)à consider HRCT in 3-6months

 

 

SPECIAL SITUATIONS
I-131 THERAPY IN PATIENT ON DIALYSIS:

-Consider pre-therapy patient-specific dosimetry (determine WB retention pre- and post-dialysis)

-Use Thyrogen (promotes uptake)

-Do therapy right after dialysis (dialysis in AM and therapy in PM)

-Wait at least 24hrs before next dialysis (no more than 48hrs)

-Consider inpatient treatment and in-hospital dialysis (so can monitor and clear dialysis machine after use)—otherwise, notify outpatient dialysis so they can plan accordingly

-Get baseline and f/u CBC to ensure no BM suppression

 

I131 IN PEDIATRICS:

-thyroid nodule rare in kids

-Avoid I131 therapy for Graves disease in <5yo; ok if dose <10mCi in 5-10yo

-FNA for cold nodule (follow up even after b9 biopsy results)

-Lobectomy for hot or autonomous nodule

-do ultrasound or neck MRI before lobectomy to assess for need for neck dissection

-aggressive pathology <10yo

-unlike adults, central neck dissection is routinely done

-unlike adults, all should get I-123 WB scan pre-therapy à if just thyroid bed uptake and stimulated TG ag<2 dont do any I131 therapy but if  TG ag>2 do remnant ablation with 30mCi; if see nodal disease or mets, do CT or MRI confirmation and assess for surgical resection rather than high dose I-131 treatment which is generally the last resort

-Bottomline: avoid high dose I131 unless absolutely needed

-OK to use Thyrogen for I131 treatment

-Consider stool softners or laxatives if history of constipation

-F/u with TG indefinately for recurrence

-Follicular CA is rare in kids and less well studied

 

VQ SCAN

Tc-DTPA aerosol

40mCi in 2cc NS via nebulizer (0.1-0.5um)

 

 

Tc-MAA

2-6mCi IV slow over 30s

(200-500k particles; 10-90um)

 

● Ask if patient may be pregnant

● Need to know if inpatient is on ventilator

Imaging protocol and tips

-V before Q: 40mCi Tc-DTPA aerosol tidal breathing x2min à 4-6mCi Tc-MAA IV

-Q before V: 2mCi Tc-MAA IV à 40mCi Tc-DTPA aerosol tidal breathing x5min

-Prefer to use mouthpiece (with nose clamped) rather than face-mask for ventilation with patient in sitting position

-Aerosol delivered via Nebulizer with 10L/min O2

-Instruct patient to breath normally (tidal breathing) without deep breaths for 2 min (do 5min if V after Q)

-Also, increase time of tidal breathing if ventilation dose is less than 40mCi (eg 2min for 40mCi, 4min for 20mCi etc)

-Lay patient down and wait 3-5min to allow aerosol to distribute evenly prior to imaging

-Check posterior count rates (prefer 100-150k cpm if V before Q or 450-500k cpm if V after Q)àif not enough counts, have patient sit up again and have them breathe additional time using same setup

-Inject Tc-MAA slow IV over 30s in supine position only (to avoid gradient) using ≥23G IV (to avoid fragmentation of particles)

-Don’t use indwelling catheters for injection like central lines (get labeled clots)

-Obtain perfusion imaging for 600k counts

-Pre-capillary arteriole blockade by MAA particles is <0.1% of all pulmonary capillary beds

-MAA particle size range 10-90um (90%) and none >150um

 

 

VQ scan r/o PE

-Indication: acute/chronic PE (especially if renal insufficiency, contrast allergy, or over CT weight limit)  

-For pediatrics and women<40yo consider perfusion-only (may do subsequent ventilation only if needed)

-Significant dose to breast tissue with CT for young females

-Reduce particles (to 100k) for peds, pregnancy, pulmonary HTN, pneumonectomy, shunt (RàL)

-Limited portable VQ scan in anterior and LAO/RAO views only for inpatients in gurney or patients who exceed table weight limit

-Wait 3-6mos before repeating VQ scan after positive study

 

Q scan only

-Indications: pregnancy; patient on ventilator; split-lung perfusion; RàL shunt

-Lower dose to 1-2mCi for pregnant patients (which reduces particles as well) and 0.03mCi/kg (min 0.3mCi) for peds

-If abnormal Q scan in pregnancy, consider V scan or skip to CTA

 

Split lung function

-Do quantitative analysis on ant and post perfusion à calculate geometric mean

-Report total L and R lung %perfusion including upper/middle/lower lung zones

-Predicted post-op FEV1 = pre-op FEV1 x %perfusion in remaining lung after lobectomy

-Desired post-op FEV1 is >0.8L or 800cc

-High risk for pulmonary complication if DLCO <40% or predicted post-op FEV1 <40%

-If pre-op FEV1 >2L or >80% predicted, patient is a candidate for pneumonectomy (FEV1 >1.5L for lobectomy) without need for split VQ scan

-Report lung ratios for single lung transplant and follow ratios to assess for rejection (development of matched defects may suggest B.O.)

 

RàL shunt

-If see significant renal/thyroid/stomach activityàimage head/neck to look for potential Free or unbound Tc (if see brain activity, it is consistent with RàL shunt)

-Do WB imagingà draw lung and WB ROI on ant and post views to determine geometric meanàcalculate %shunt = [(WB – lung) / WB] x 100

-Shunt >5% is considered significant

-Alternative technique: may use activity within brain and kidneys to estimate total systemic activity as below

Systemic counts= (brain+renal) / 0.32

WB counts= systemic counts + lung counts

Shunt= [(WB – Lung)/WB] x 100%

 

 

XOFIGO

THERAPY

Ra-223 dichloride

1.49uCi/kg IV slow over 1min

● Keep well hydrated

● 1week before therapy get labs (check for eligibility) and check exact weight (for dose determination)

● Dose has to be ordered 1wk prior to treatment date

● Make sure patient understands there will be q4 week injections x6 (over 6months)--must complete entire course

 

 

 

 

 

 

Radium-223:

-T1/2=11.4d

-Alpha 93.5% <4% beta, <2% gamma

-Energy=5.78MeV (20x more energy than Sr-89)

-Range=<100um (0.1mm or 10cell diameter); in comparison Sr-89 range is ~8mm

-Quality factor=20 (beta=1)—high LET unlike beta which is low LET

CRITERIA:

-CRPC (castrate-resistant prostate CA) with symptomatic osteoblastic bone mets (≥2 lesions on bone scan within 6mos of treatment)

-No visceral mets (LN involvement ok)

-No concurrent or recent chemo (within 6wks)

-ANC ≥1.5, Platelets≥100, and Hgb≥10 for 1st dose

-ANC≥1.0 and Platelets≥50 for all subsequent doses

-Concurrent bisphosphonate therapy ok

 

SIDE EFFECTS:

-common: n/v/d, peripheral edema (arms/legs), BM suppression (cytopenia)

-uncommon: dehydration, pain/swelling/redness at injection site

 

WRITTEN SAFETY INSTRUCTIONS:

-Urine precautions x1wk

-Universal precautions (especially handily any bodily fluid like vomitus, stool, or urine)

-Wear disposable diapers if incontinence or diarrhea and use gloves when changing or cleaning

-Avoid contraception (condoms) and avoid pregnancy x1yr

-No surgery/dental work for next 24hrs

-Take laxatives if get constipated and take Imodium if get diarrhea

-Pain may temporarily worsen (usually see pain relief after 2nd injection)

-If bleeding, signs of infection, or uncontrolled v/d, contact oncologist

 

ADMINISTRATION:

-Check CBC and WBC differential within 1 week of therapy

-Check patient weight to calculate dose

-Written directive

-Order dose 1 week prior to date of therapy

-Verify dose in dose calibrator (use CF for Ra-223)

-Get signed consent and give written instructions for radiation safety

-Start ≥23G IV and give 250cc NS IV (wide open)

-A.U. to inject Ra-223 slow IV over 1min and flush syringe with NS (using 3 way stop) to avoid any residual activity in syringe

-Measure residual syringe activity in dose calibrator

-Dispose syringe and IV tubing in shielded decay container

-Remind patient to go to lab in 3weeks and come to NM for weight check

-If need to delay next dose b/c of BM suppression, can delay upto 8wks btwn doses (but if longer than 8wks, can no longer give additional dose for future)

 

 

RESPONSE:

● Disease response better assessed with Alk Phos rather than PSA; if there is concern for disease progression while on Xofigo, consider CT after 3rd-4th Xofigo dose to look for non-osseous progression (osseous progression while on Xofigo is rare); also consider bone scan after completion of six Xofigo treatment and compare to pre-treatment bone scan

● Median survival 15months compared to 11 months for placebo

● 34% reduction in risk of symptomatic skeletal events

● ALK decreases up to 30% at 2yrs

● 16% of patients achieve 30% or more reduction in PSA

 

 

Y-90 RADIOEMBO.

Tc-MAA 4mCi  IV for

pre-therapy planning

 

Y-90 Theraspheres or

SIR-spheres for therapy

 

BASIC CONCEPTS:

-SIRT=selective internal radiotherapy of liver with Sirspheres (resin) or Theraspheres (glass)

-Contraindications: pregnancy, life expectancy<1month, PV thrombosis, severe hepatic insufficiency (child-pugh score >B7), active hepatitis, rising bilirubin, disseminated extra-hepatic dz, contraindications to HA catheterization (like coagulopathy, contrast allergy, renal failure)

-Pre-therapy hepatic angio for vascular mapping (detect replaced HA; variable supply to segment 4), prophylactic coil embolization to avoid non-targeted embolization (like GDA, cystic artery etc), and for delivery of Tc-MAA

-Tc-MAA planar ant/post chest and upper abdomen static imaging to assess for LSF lung shunt fraction (<10% of no consequence while >20% is contraindication for radioembolization)

-LSF =  lung counts / (lung + liver counts)

-Also perform Tc-MAA SPECT/CT to assess liver volume, tumor volume, tumor:non-tumor ratio; and look for extra-hepatic deposition

-Theraspheres approved for HCC (can be neoadjuvant; partial or branch PVT ok); SIR-spheres approved for liver mets from CRC or NET

-Theraspheres have less embolic effect; are heavier (higher specific gravity) and less homogenous distribution

-Dose calculation for Theraspheres via partition method (don’t treat if >16.5mCi to lungs)

-Dose calculation for SIR-spheres using BSA method (SIR-spheres have lower specific activity and therefore more embolic effect and more painful)à10% dose reduction if 10-15% LSF; 40% reduction if 15-20% LSF; don’t treat if >20% LSF

-Highest tolerable dose to lung is 30Gy after single tx (or 50Gy after repeated tx)

-Highest dose to non-tumor liver should be <70Gy (<50Gy for cirrhotic liver)

-Split prescribed dose if both right and liver lobe is treated (1/3 left and 2/3 right)

-Post-therapy SPECT/CT (using bremsstrahlung 90keV with 30% window using MEGP b/c has weak positron emission) or PET/CT (using pair production) for documenting delivery to target region and for prognosis

-Complications: liver failure (fibrosis or portal HTN), tumor lysis syndrome (pain/fever/n/v), infx, radiation pneumonitis, pancreatitis, intractable ulcers/gastritis, cholecystitis

 

ZEVALIN THERAPY

Y-90 Ibritumomab tiuxetan

0.3-0.4mCi/kg (max 32mCi) IV slow over 10min (using 0.22um low-protein binding filter)

● No prior anaphylaxis or HAMA rxn to Rituximab

● <25% BM involvement (correlate with BM biopsy within 6wks)

● No prior failed BM stem cell transplant

● Platelets >100k and PMNs (neutrophils) >1.5

● Adequate renal fxn

● No pregnancy and not breastfeeding

 

 

Y-90 characteristics:

-Pure beta

-T/1=2.7d

-Energy=2.29MeV max and 935keV avg (I-131 is 0.606MeV max and 183keV avg)

-Range=12mm max and 5mm avg (I-131 is 2mm max and 0.8mm avg)

-Bremsstrahlung gamma allow SPECT imaging

-Pair-production (electron + positron) allow PET imaging

● Zevalin prolongs PFS x2yrs and have higher PR to CR conversion rates

● Bexxar (I-131 Tositumomab) NO LONGER AVAILABLE (give KI for thyroid protection; need dosimetric scan for biodistribution before therapy)

 

INDICATION:

-Relapsed or Refractory B-cell NHL (CD20+)ßincluding Rituximab refractory

-Low grade or Follicular B-cell lymphoma (also safe and effective in DLBCL)

-Newly diagnosed follicular NHL (CD20+) after partial/complete response to first line chemo

-Follicular lymphoma in patient who are not responding to Rituximab

-BM involvement <25%

-Note: Bexxar is approved for “Transformed” NHL

 

CONTRA-INDICATIONS:

-25% BM involvement

-Impaired BM reserves (15% cellularity)

-ANC <1.5 and platelets <100k

-Failed stem cell collection

-Prior allergy to Zevalin

 

POTENTIAL SIDE-EFFECTS:

-common rxn include n/v/d, fatigue, abd pain, cough, pharyngitis, fever (mild flu like symptoms with Rituximab)

-severe infusion rxn* (can be fatal; 80% occur with first rituximab infusion)

-mucocutaneous/cutaneous rxn*

-beta burn with extravasation (elevate arm, apply heating pad, consider Amifostine)

-Cytopenias (BM suppression slightly higher with Bexxar than Zevalin)

-secondary malignancy (like leukemia) and MDS

-HAMA (alters biodistribution and reduces effectiveness of effective tumor dose)

*=stop infusion if these occur (higher risk of HAMA with Bexxar than Zevalin)

 

DOSING “RRZ”:

-In 2011, FDA lifted requirement for pre-therapy scan with In-111 for biodistribution assessment

-Can use port for infusion

-Check vitals and premedicate with 650mg Tylenol and 50mg Benadryl PO à Rituximab 250mg/m2 IV infusion on day1 (takes 4hr; nurse to monitor vitals)

-On day 7 or 8 or 9, check vitals and premedicate with 650mg Tyelenol and 50mg Benadryl PO à Rituximab 250mg/m2 IV infusion (takes 4hr; nurse to monitor vitals) à within 4hrs à Zevalin 0.4mCi/kg  (if platelets ≥150k) or 0.3mCi/kg (if platelets 100-149k) for max dose of 32mCi

-Inject Zevalin slow over 10min using 0.22um low-protein binding filter (pre-wet with sterile NS) and flush syringe with NS using 3way stop arrangement

-Use lucite syringe shield over Zevalin for protection

 

PRECAUTIONS:

-Urine precautions x3d

-Use universal precautions

-No pregnancy x1yr after treatment (use condoms for sex x1wk)

-Response rate is 70-80% (30% may have complete response) and median duration of response is 14-18mos

 

NM & PET DOSE GUIDE 

 
      NM adults radiopharmaceutical dose chart 1
                        
      NM adult radiopharmaceutical dose chart 2
      NM adult radiopharmaceutical dose chart 3
       NM adult radiopharmaceutical dose chart 4
NUCLEAR MEDICINE DOSES NORMAL RANGE DOISNG RANGE RADIOPHARMACEUTICAL DOSE NM RADIOPHARMACEUTICAL RP DOSE CHART GUIDE ADULT PROTOCOL

 NORMAL

PEDIATRIC DOSING
CLICK LINK BELOW FOR 2010 NORTH AMERICAN CONSENSUS GUIDELINES
:

http://interactive.snm.org/docs/Pediatric_dose_guidelines_JNM_2011_52_318.pdf

CLICK LINK BELOW FOR EANM PEDS DOSE CALCULATOR:
http://www.eanm.org/publications/dosage-calculator/

Pediatric radiotacer dose Nuc Med 1Peds Nuclear Medicine dose EANM






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