title: Scintigraphic localization of pheochromocytoma.
abstract: We used a new radiopharmaceutical agent, [131I]meta-iodobenzylguanidine ([131I]MIBG), to produce scintigraphic images of pheochromocytomas in eight patients. One day or more after injection, the only normal organ that displayed distinct concentrations of radioactivity was the urinary bladder. The [131I]MIBG was probably concentrated in adrenergic vesicles; in tissues where vesicles are numerous, such as pheochromocytomas, the radionuclide was retained for days. The spectrum of pheochromocytomas shown the scintigrams was broad: intra-adrenal and extraadrenal in location, benign and malignant in character, 0.2 to 65 g in weight, and with different hormone patterns in secretion. Tumors in four patients were not detected by computed tomography. In one patient, reoperation was undertaken only because the scintigram located the extra-adrenal tumors and thereby directed the surgeon's exploration. The method offers hope of safe and reliable localization of pheochromocytomas in their many guises.
mesh_terms: D019797:3-Iodobenzylguanidine; D000293:Adolescent; D000310:Adrenal Gland Neoplasms / Q000000981:diagnostic imaging* / Q000378:metabolism; D000328:Adult; D004837:Epinephrine / Q000097:blood / Q000652:urine; D005260:Female; D006146:Guanidines; D006801:Humans; D007457:Iodine Radioisotopes; D008297:Male; D008676:Metanephrine / Q000652:urine; D008875:Middle Aged; D009638:Norepinephrine / Q000097:blood / Q000652:urine; D009647:Normetanephrine / Q000652:urine; D010673:Pheochromocytoma / Q000000981:diagnostic imaging* / Q000378:metabolism / Q000556:secondary; D011877:Radionuclide Imaging
chemical_list: D006146:Guanidines; D007457:Iodine Radioisotopes; D009647:Normetanephrine; D019797:3-Iodobenzylguanidine; D008676:Metanephrine; D009638:Norepinephrine; D004837:Epinephrine