Upfront consolidation treatment with (131)I‐mIbG followed by myeloablative chemotherapy and hematopoietic stem cell transplantation in high‐risk neuroblastoma

IMPORTANCE: (131)I‐metaiodobenzylguanidine ((131)I‐mIBG) has a significant targeted antitumor effect for neuroblastoma. However, currently there is a paucity of data for the use of (131)I‐mIBG as a “front‐line” therapeutic agent in those patients with newly diagnosed high‐risk neuroblastoma as part of the conditioning regimen for myeloablative chemotherapy (MAC). OBJECTIVE: To evaluate the feasibility of upfront consolidation treatment with (131)I‐mIBG plus MAC and hematopoietic stem cell transplantation (HSCT) in high‐risk neuroblastoma patients. METHODS: A retrospective, single‐center study was conducted from 2003–2019 on newly diagnosed high‐risk neuroblastoma patients without progressive disease (PD) after the completion of induction therapy. They received (131)I‐mIBG infusion and MAC followed by HSCT. RESULTS: A total of 24 high‐risk neuroblastoma patients were enrolled with a median age of 3.0 years at diagnosis. After receiving this sequential consolidation treatment, 3 of 13 patients who were in partial response (PR) before (131)I‐mIBG treatment achieved either complete response (CR) (n = 1) or very good partial response (VGPR) (n = 2) after HSCT. With a median follow‐up duration of 13.0 months after (131)I‐mIBG therapy, the 5‐year event‐free survival and overall survival rates estimated were 29% and 38% for the entire cohort, and 53% and 67% for the patients who were in CR/VGPR at the time of (131)I‐mIBG treatment. INTERPRETATION: Upfront consolidation treatment with (131)I‐mIBG plus MAC and HSCT is feasible and tolerable in high‐risk neuroblastoma patients, however the survival benefit of this (131)I‐mIBG regimen is only observed in the patients who were in CR/VGPR at the time of (131)I‐mIBG treatment.