High-dose 131I-mIBG as consolidation therapy in pediatric patients with relapsed neuroblastoma and ganglioneuroblastoma: the Japanese experience

Objective Children with relapsed neuroblastoma have a poor prognosis despite modern multimodality therapy. Novel and more effective therapeutic strategies are required for relapsed neuroblastoma. We retrospectively examined the utility of consolidation therapy with high-dose 131 I-meta-iodo-benzyl-guanidine ( 131 I-mIBG) in relapsed neuroblastoma or ganglioneuroblastoma patients with complete response (CR) to induction therapy as demonstrated by diagnostic 123 I-mIBG scintigraphy. Methods Between December 2009 and 2014, five patients with relapsed neuroblastoma and one with relapsed ganglioneuroblastoma received high-dose 131 I-mIBG therapy. Overall and progression-free survival rates at five years after 131 I-mIBG therapy were analyzed by the Kaplan–Meier method. Results During follow-up, three children showed no signs of disease relapse, whereas three died. One child without a relapse died from post-transplant side effects, and two children with a relapse died owing to tumor progression. The 5-year progression-free and overall survival rates after 131 I-mIBG therapy were 44% and 67%, respectively. Conclusions Consolidation therapy with high-dose 131 I-mIBG for patients with 2 nd CR showed good overall and progression-free survival. While the risks of radiation exposure must be considered, high-dose 131 I-mIBG therapy as consolidation therapy needs to be further investigated.