131I-metaiodobenzylguanidine in the treatment of neuroblastoma at diagnosis.

Radioactive metaiodobenzylguanidine (131I-MIBG) is taken up specifically by neuroblastoma cells and appears to represent a new treatment modality in patients with advanced neuroblastoma. Taking into account the fact that all patients so far treated were heavily pretreated and resistant to chemotherapy, the results obtained appear encouraging. In order to explore further the potential role of this new drug in untreated patients, we treated with 131I-MIBG a child with stage III neuroblastoma at diagnosis. We observed the complete disappearance of a large abdominal tumor mass after a relatively low dosage of 131I-MIBG, with minimal hematologic toxicity. No further treatment was given and, at present, the patient is alive with no evidence of disease 18 months from diagnosis. This child represents, to our knowledge, the only case of neuroblastoma thus far treated at diagnosis and the excellent response obtained suggests the need for further investigations of this therapy in untreated patients.