Treatment of neuroblastoma with [125I]metaiodobenzylguanidine.

To find a treatment that may be effective against micrometastases of advanced, stage III or IV neuroblastoma, [125I]metaiodobenzylguanidine (125I-MIBG) was used in a phase I toxicity trial. In seven patients, thrombocytopenia was encountered with absorbed whole body doses of 85-135 rad from 125I-MIBG, but the dosimetry was imprecise in predicting bone marrow injury. Three patients survived for over one year, results that may indicate efficacy of 125I-MIBG therapy.