Experience with I-131-metaiodobenzylguanidine (MIBG): a retrospective study.

We report a retrospective study of two years experience with I-131-metaiodobenzylguanidine (MIBG). I-131 MIBG was prepared locally and was found to have decreased background activity as compared with other available commercial preparations from Great Britain and the United States. Fifty-nine patients were studied with a total of 65 scans. The study included 11 members of a family with multiple endocrine adenomatosis (MEA) type II syndrome. Of 16 patients found to have abnormal scans, 12 had disease confirmed surgically. These cases consisted of nine pheochromocytomas, one paraganglioma, one neurilemmoma, and one neuroblastoma. MIBG scans for pheochromocytoma detection had an accuracy of 94.5%, a sensitivity of 100%, and a specificity of 93.5% in this study of patients with a high prior probability of the disease.