Thyroid and hepatic function after high-dose 131I-metaiodobenzylguanidine (131I-MIBG) therapy for neuroblastoma

Abstract

Background: 131I-Metaiodobenzylguanidine (131I-MIBG) provides targeted radiotherapy for children with neuroblastoma, a malignancy of the sympathetic nervous system. Dissociated radioactive iodide may concentrate in the thyroid, and 131I-MIBG is concentrated in the liver after 131I-MIBG therapy. The aim of our study was to analyze the effects of 131I-MIBG therapy on thyroid and liver function.Procedure: Pre- and post-therapy thyroid and liver functions were reviewed in a total of 194 neuroblastoma patients treated with 131I-MIBG therapy. The cumulative incidence over time was estimated for both thyroid and liver toxicities. The relationship to cumulative dose/kg, number of treatments, time from treatment to follow-up, sex, and patient age was examined.Results: In patients who presented with Grade 0 or 1 thyroid toxicity at baseline, 12-±-4% experienced onset of or worsening to Grade 2 hypothyroidism and one patient developed Grade 2 hyperthyroidism by 2 years after 131I-MIBG therapy. At 2 years post-131I-MIBG therapy, 76-±-4% patients experienced onset or worsening of hepatic toxicity to any grade, and 23-±-5% experienced onset of or worsening to Grade 3 or 4 liver toxicity. Liver toxicity was usually transient asymptomatic transaminase elevation, frequently confounded by disease progression and other therapies.Conclusion: The prophylactic regimen of potassium iodide and potassium perchlorate with 131I-MIBG therapy resulted in a low rate of significant hypothyroidism. Liver abnormalities following 131I-MIBG therapy were primarily reversible and did not result in late toxicity. 131I-MIBG therapy is a promising treatment for children with relapsed neuroblastoma with a relatively low rate of symptomatic thyroid or hepatic dysfunction. © 2010 Wiley-Liss, Inc.