The use of [131I]metaiodobenzylguanidine in the treatment of neuroblastoma after conventional therapy.

Eleven cases of neuroblastoma (10 males and 1 female; 9 aged 1-13 years, and two aged 17 and 38 years, respectively) ten of which were refractory to chemotherapy, were submitted to treatment with [131I]metaiodobenzylguanidine (131I-MIBG). The therapeutic procedure consisted essentially of single doses (2.6-9.5 GBq) of 131I-MIBG mostly split into two parts, administered by slow i.v. infusion and given in several therapeutic courses, usually at 1-2 month intervals. The treatment resulted in: 1 complete response, 1 partial response, 1 minor response, 4 stabilized diseases and 2 progressive diseases (two patients were not evaluable due to rapid progression of the disease). Pain relief was observed in all cases and particularly in four patients who suffered severe tumor pain. The major side-effects recorded were: hypertensive crises over a 6-day period in one case, fever lasting a few days in another and bone marrow depression in two intensively pretreated patients. A slight hematologic toxicity was observed, however, in almost all cases.