☢️ Scintigrafie cu I-123 / I-131 MIBG (Metaiodobenzilguanidină)

Updated MIBG Scan 9/8/2024 ●Indication  To detect, localize, stage and follow neuroendocrine tumors and their metastases (pheochromocytomas, neuroblastomas, ganglioneuroblastomas, ganglioneuromas, paragangliomas, carcinoid tumors, medullary thyroid carcinomas, Merkel cell carcinoma, MEN2 syndromes), study of tumor uptake and residence time in order to decide and plan a treatment with high activities of radiolabeled MIBG, evaluation of tumor response to therapy by measuring the intensity of MIBG uptake and the number of focal MIBG uptake sites and confirmation of suspected tumors derived from neuroendocrine tissue. ●Radiopharmaceutical: 10 mCi I-123 MIBG administered IV via a peripheral vein slowly over 5 mins ●Patient Preparation:  The patient will need iodine blockade of his/her thyroid using 130 mg potassium iodide capsules. One capsule the morning before, 1 capsule the morning of and 1 capsule the morning after MIBG administration. Patients allergic to iodine can receive
1 capsule of 400 mg potassium perchlorate the morning of MIBG administration. Have the patient drink 16-20 oz of water 30-60 mins prior to exam to ensure adequate hydration.  Have the patient empty his/her bladder immediately prior to imaging. Instruct the patient to void frequently for a day following the exam. ●Conflicting Examinations/Medications: Numerous substances interfere with MIBG localization. See following list for specific hold times. Patients should hold caffeine for 24 hrs.  Patients with catecholamine-secreting pheochromocytomas and paragangliomas may be receiving alpha or beta-blockade and may be unable to hold these medications. No Nuclear Medicine exams within the previous 24 hrs. No barium GI exams within the previous 48 hrs. ●Pregnancy/Lactation:  Pregnancy testing is only needed in potentially pregnant patients who state they could be pregnant. See Pregnant, Potentially Pregnant and Lactating Patients policy for specifics. Breast milk should be discarded for 2 days following I-123 MIBG administration. ●Imaging Technique: Collimator - LEHR or medium energy high resolution Photopeak - 159 keV 20% window for I-123 Image Preset Counts ◦Whole Body Images - 5 cm/min ◦Static Images - 500k counts/image or 10 mins/image ◦SPECT Images - 60 stops, 25-35 secs/stop Matrix Size - 256 x 1024 (whole body), 256 x 256 (static), 128 x 128 (SPECT) Patient Positioning - supine ●Imaging Views: Standard Images ◦Obtain anterior and posterior whole body images (eyes to thigh) at 24 hrs. ◦Add static images of any focal findings at the discretion of the Nuclear Medicine Technologist. ◦ Check with the Radiologist before discharging the patient to see if any additional static imaging of a particular area or
48 hrs imaging is needed. SPECT Images (Only if Requested) ◦Check with the Radiologist to determine the anatomical coverage for SPECT images. ◦Obtain SPECT images with axial, coronal and sagittal reconstructions after the 24 hrs static images are obtained. ◦Obtain a 3D horizontal spinner.

●Medications/Substances to Hold: amisulpride 72 hrs guanethidine 48 hrs phenylephrine 48 hrs amitriptyline 48 hrs haloperidol 48 hrs pimozide 72 hrs amlodipine 48 hrs haloperidol depot 1 mth prochlorperazine 24 hrs amoxapine 48 hrs imipramine 48 hrs promethazine 24 hrs amphetamines 48 hrs isradipine 48 hrs pseudoephedrine 48 hrs atomoxetine 5 days labetalol 72 hrs quetiapine 48 hrs brimonidine 48 hrs methylphenidate 48 hrs reserpine 48 hrs caffeine 24 hrs mirtazapine 8 days risperidone 5 days chlorpromazine 24 hrs modafinil 72 hrs risperidone depot 1 mth clomipramine 24 hrs nicardipine 48 hrs salmeterol 24 hrs clozapine 7 days nifedipine 24 hrs terbutaline 24 hrs cocaine 24 hrs nimodipine 24 hrs thioridazine 24 hrs diltiazem 24 hrs nisoldipine 48 hrs tramadol 24 hrs dobutamine 24 hrs norepinephrine 24 hrs trifluoperazine 48 hrs dopamine 24 hrs nortriptyline 24 hrs trimipramine 48 hrs doxepin 24 hrs olanzapine 7-10 days venlafaxine 48 hrs ephedrine 24 hrs oxymetazoline 24 hrs verapamil 48 hrs felodipine 48 hrs perphenazine 24 hrs fluphenazine 24 hrs phenoxybenzamine IV 15 days fluphenazine depot 1 mth phenylephrine 24 hrs ●Notes: MIBG is an analogue of noradrenaline and guanethidine.  Adverse effects of MIBG administration include tachycardia, pallor, vomiting and abdominal pain and are minimized by administration via a peripheral vein slowly over 5 mins.  Physiologic distribution of MIBG is primarily in the liver, adrenal glands, kidneys and bladder. Lesser degrees of uptake can be visualized in the spleen, lungs, salivary glands, skeletal muscles and myocardium.  MIBG may also accumulate to variable degrees in the nasal mucosa, lungs, gallbladder, colon and uterus. Free iodine in the bloodstream may cause some uptake in the digestive system and in the thyroid. Skeletal uptake should not be seen. Extremities should show only slight muscular activity.  MIBG soft-tissue uptake is observed in primary tumour and in metastatic sites including lymph nodes, liver, bone and bone marrow. Increased uptake in the skeleton (focal or diffuse) is indicative of bone marrow involvement and/or skeletal metastases.