SURVIVAL OF PATIENTS WITH NEUROBLASTOMA TREATED WITH 125-I MIBG

Recurrent or persistent neuroblastoma in stages III and IV is usually fatal despite modem therapies. Metaiodobenzyl-guanidine labeled with 1 31-I (131-I MIBG) concentrates in most neuroblastomas and, when given in doses that impart therapeutic radiation, has produced remissions in patients with these tumors. However, success with 131-I MIBG has been limited. The physical characteristics of radiation imparted by 125-I MIBG theoretically could overcome some of the limitations that restrai n the therapeutic effects of 131-I MIBG in patients with neuroblastoma . Thereby, 125-I MIBG may offer advantages over 131-I MIBG in the trea tment of neuroblastoma. Ten children who manifested persistent/recurre nt stage III or IV neuroblastoma were given 8.3 to 30.1 GBq or 224 to 814 mCi of 125-I MIBG in a phase I-II trial. Five of the patients had progression-free survivals >1 year(continuing in three patients), and four of these subjects are surviving 17 to 52 months after treatment w ith 125-I MIBG. With appropriate doses of 125-I MIBG, life-threatening toxicity can be avoided. Thus, survivals after 125-I MIBG appear to b e as long or longer than those historically observed following other t reatments for patients similarly afflicted with refractory neuroblasto ma.