title: [131I]metaiodobenzylguanidine in neuroblastoma patients at diagnosis.
abstract: Treatment of resistant neuroblastoma with high dosage [131I]metaiodobenzylguanidine (131I-MIBG) appears effective since encouraging results have been obtained so far even in patients with very advanced, intensively pre-treated disease. We have already reported a stage III NB patient treated at diagnosis, who is at present in complete remission with a 4-year follow-up. To further explore the potential role of this new drug in untreated patients, we administered radionuclide to two children with stage III neuroblastoma. Both cases received 131I-MIBG at relatively low doses, and showed a significant reduction of the tumor mass and, interestingly enough, no evidence of 131I-MIBG uptake of a tracer dose in the remaining tumor. Particularly in case 1, the permanence and subsequent progression of the part of the tumor mass without 131I-MIBG uptake, after therapeutic doses of 131I-MIBG which apparently destroyed the 131I-MIBG-positive cell population, clearly suggest heterogeneity at diagnosis, with a dual neuroblastoma cell population, one with 131I-MIBG uptake and the other without. Aside from the biological implications of the heterogeneous MIBG uptake in neuroblastoma at diagnosis, our findings suggest that in stage III neuroblastoma patients even a relatively small dose of 131I-MIBG administered at diagnosis is sufficient to either completely destroy the primary tumor, as reported by our group, or to destroy that part of the tumor which shows 131I-MIBG uptake (as in the present cases), without any significant hematologic toxicity. Furthermore, a single course of 131I-MIBG at the dosage employed here does not appear to jeopardize the subsequent use of chemotherapy.(ABSTRACT TRUNCATED AT 250 WORDS)
authors.affiliation: Division of Pediatric Oncology, Università Cattolica del Sacro Cuore, Rome, Italy.
authors.forename: R
authors.initials: R
authors.lastname: Mastrangelo
authors.forename: A
authors.initials: A
authors.lastname: Lasorella
authors.forename: L
authors.initials: L
authors.lastname: Troncone
authors.forename: V
authors.initials: V
authors.lastname: Rufini
authors.forename: A
authors.initials: A
authors.lastname: Iavarone
authors.forename: R
authors.initials: R
authors.lastname: Riccardi
mesh_terms: D019797:3-Iodobenzylguanidine; D000970:Antineoplastic Agents / Q000627:therapeutic use*; D002675:Child, Preschool; D003131:Combined Modality Therapy; D005260:Female; D006801:Humans; D007457:Iodine Radioisotopes / Q000627:therapeutic use*; D007462:Iodobenzenes / Q000627:therapeutic use*; D009447:Neuroblastoma / Q000000981:diagnostic imaging / Q000628:therapy*; D011877:Radionuclide Imaging
chemical_list: D000970:Antineoplastic Agents; D007457:Iodine Radioisotopes; D007462:Iodobenzenes; D019797:3-Iodobenzylguanidine