Upfront consolidation treatment with 131I-mIBG followed by myeloablative chemotherapy and hematopoietic stem cell transplantation in high-risk neuroblastoma

Importance:131I-metaiodobenzylguanidine(131I-mIBG)has a significant targeted antitumor effect for neuroblastoma.However,currently there is a paucity of data for the use of 131I-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 131I-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 131I-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 131I-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 131I-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 131I-mIBG treatment.Interpretation:Upfront consolidation treatment with 131I-mIBG plus MAC and HSCT is feasible and tolerable in high-risk neuroblastoma patients,however the survival benefit of this 131I-mIBG regimen is only observed in the patients who were in CR/VGPR at the time of 131I-mIBG treatment.