Critical observations on neuroblastoma treatment with 131-I-metaiodobenzylguanidine at diagnosis.
Results of treatment with 131-I-Metaiodobenzylguanidine (131-I-MIBG) in patients with resistant neuroblastoma appear encouraging if one considers that most of the patients had far advanced, intensively pre-treated disease. To further explore the potential role of this new drug in untreated patients, we treated 3 children with stage III neuroblastoma. All three of our cases received 131-I-MIBG at relatively low dose with the complete disappearance of the tumor mass in case 1, whereas in cases 2 and 3 CT scan showed a significant reduction of the tumor mass and, interestingly enough, no evidence of 131-I-MIBG uptake of a tracer dose in the remaining tumor. Particularly, in case 2, the persistence and subsequent progression of part of the tumor mass without 131-I-MIBG uptake after a therapeutic dose of 131-I-MIBG, which apparently destroyed the 131-I-MIBG-positive cell population, clearly suggest heterogeneity at diagnosis, with a dual neuroblastoma cell population, one with 131-I-MIBG uptake and the other without. Besides the biological implications of the 131-I-MIBG uptake heterogeneity in neuroblastoma at diagnosis, our findings suggest that in stage III neuroblastoma patients even a relatively small dose of 131-I-MIBG administered at diagnosis is sufficient to destroy either the primary tumor completely (case 1) or the part of the tumor (case 2 and 3) which shows 131-I-MIBG uptake, without any significant hematologic toxicity. Furthermore, a single course of 131-I-MIBG at the dosage employed does not appear to jeopardize the subsequent use of chemotherapy. In conclusion, if our data are confirmed by further investigation, 131-I-MIBG may be included as a front line drug shortly followed by chemotherapy in future treatment strategies of advanced neuroblastoma without or with minimal bone marrow infiltration.
Division of Pediatric Oncology, Catholic University of the Sacred Heart, Rome, Italy.
R
R
Mastrangelo
A
A
Lasorella
A
A
Iavarone
V
V
Rufini
L
L
Troncone
F
F
Danza
R
R
Riccardi
D019797:3-Iodobenzylguanidine; D002675:Child, Preschool; D005260:Female; D006801:Humans; D007223:Infant; D007457:Iodine Radioisotopes / Q000627:therapeutic use*; D007462:Iodobenzenes / Q000627:therapeutic use*; D008297:Male; D009447:Neuroblastoma / Q000175:diagnosis / Q000532:radiotherapy*
D007457:Iodine Radioisotopes; D007462:Iodobenzenes; D019797:3-Iodobenzylguanidine