[131I]metaiodobenzylguanidine therapy in advanced neuroblastoma.

Forty-two children with advanced neuroblastoma who either failed with first-line therapy or relapsed after achieving a complete remission, were considered for treatment with [131I]metaiodobenzylguanidine (131I-MIBG). We subdivided 42 cases into 5 groups, in accordance with the stage of disease at diagnosis, response to first-line therapy and relapse. A total of 99 courses of 131I-MIBG were administered with doses ranging from 2.8 to 6.0 GBq. One child received six courses, 3 four courses, 18 three courses, 6 two courses and 15 one course of 131I-MIBG. The total delivered dose in single measurable lesions ranged from 286 to 1691 cGy with an uptake factor ranging from 3% to 10%. We obtained a major response in primary tumors, and a long-term response was observed in 5 cases, lasting more than 2 years without further chemotherapy.