131I-Meta-Iodobenzylguanidine Therapy for Pheochromocytoma/Paraganglioma and Neuroblastoma

Abstract

Patients with malignant/metastatic pheochromocytoma/paraganglioma (PHEO/PG) benefit from 131I-meta-iodobenzylguanidine (131I-mIBG) treatment: symptomatic response is high, ranging between 75 and 90 %, biochemical response rate is 45–74 %, and morphologic response is 27–47 %. Nevertheless, complete response is low, ranging from 0 to 18 %, whereas 5-year survival ranges between 45 and 85 %. Patients with neuroblastomas (NB), after 131I-mIBG treatment, have 65 % 2-year overall survival. For the majority of adult patients with PHEO/PG or NB, a realistic goal is to stabilize disease, provide symptomatic relief, and elicit biochemical response. For younger patients with refractory or relapsing NB, already burdened by prior therapies, therapeutic 131I-mIBG is considered when other treatment options are ineffective. In the future, high-purity, carrier-free 131I-mIBG may be further used and assessed.