131I]metaiodobenzylguanidine therapy in paraganglioma.

Our experience with [131I]metaiodobenzylguanidine (131I-MIBG) therapy in a 10 year old boy is reported. At disease onset, in May 1988, this boy presented a large mass in the upper left abdominal quadrant, which was resected with a histopathological diagnosis of extra-adrenal malignant pheochromocytoma (paraganglioma). He subsequently underwent two further surgical resections and chemotherapy. When 131I-MIBG therapy was started, in June 1990, skeletal and abdominal metastases were present. These localizations were revealed by 131I-MIBG scans and confirmed by x-ray examination. At present 6 courses of therapy have been performed with a cumulative activity of 29.6 GBq. Side-effects have been limited to vomiting and mild thrombocytopenia, lasting 2 weeks during the second course of therapy. After 15 months of therapy, a progressive reduction of MIBG uptake, coupled with a stabilization of the lythic lesions, has been observed.