Treatment of advanced neuroblastoma in children over 1 year of age: The critical role of (131) I-metaiodobenzylguanidine combined with chemotherapy in a rapid induction regimen.

BACKGROUND: The prognosis of patients with advanced neuroblastoma (NB) remains poor. Major and early responses have an important bearing on treatment outcome. Iodine-131-metaiodobenzylguanidine (131I-MIBG) has the potential to deliver large doses of radiation specifically to NB cells. We evaluated the toxicity of, and response to, a novel induction regimen that included 131I-MIBG combined with cisplatin, cyclophosphamide, etoposide, vincristine, and doxorubicin. PROCEDURE: Thirteen children over 1 year of age with advanced NB at diagnosis were investigated extensively. 131I-MIBG was administered on day 10; this was preceded by chemotherapy in the five patients in group 1 (described in our previous study), and both preceded and followed by chemotherapy in the eight patients in group 2. The final induction regimen (used for group 2) lasted 1 month. Evaluation was performed 40 days after the start of treatment. RESULTS: In both groups 1 and 2, the extent of hematologic toxicity, which was the only side effect, was similar to that seen with chemotherapy alone. Doses of 131I-MIBG as high as 16.6 mCi/kg showed no evidence of toxicity, even in patients with extensive bone marrow infiltration. Overall, we recorded two patients with a complete response (CR), six very good partial responses (VGPR), four partial responses (PR), and one mixed response (MR). In group 2, CR/VGPR were observed in patients treated with higher doses of 131I-MIBG. CONCLUSIONS: The results of this pilot study show that 131I-MIBG, in combination with chemotherapy, appears to play an important role in a new and effective induction regimen for advanced NB.