Phase I/II study of iodine 131 metaiodobenzylguanidine in chemoresistant neuroblastoma: a United Kingdom Children's Cancer Study Group investigation.

Abstract

PURPOSEThe goal of this study was to evaluate the toxicity of iodine 131 metaiodobenzylguanidine (mIBG) in metastatic neuroblastoma.PATIENTS AND METHODSA multicenter phase I study of 131I mIBG has been undertaken by the United Kingdom Children's Cancer Study Group (UKCCSG) in children with advanced chemoresistant neuroblastoma. Activity prescription was based on a prescribed whole-body radiation dose, which was established for individual patients by performing an initial tracer investigation with 75 MBq of 131I mIBG. An activity was derived from this pharmacokinetic study that would deliver an initial whole-body-absorbed radiation dose of 1 Gy. Subsequent dose escalations were based on observed toxicity.RESULTSTwenty-five patients, aged 1 to 10 years, were treated with prescribed whole-body dose levels of 1.0 Gy (n = 2), 2.0 Gy (n = 13), and 2.5 Gy (n = 10). This necessitated administration of 2.4 to 12.1 GBq of activity. Hematologic, hepatic, kidney, and adrenal toxicity were observed, with bone marrow s...