Background:

Follow-up data on patients with neuroblastoma treated with high-dose ¹³¹I-MIBG therapy for both metastatic disease and bone marrow ablation prior to transplantation remain limited. This study aimed to evaluate clinical outcomes and post-therapy imaging findings in patients receiving high-dose MIBG as part of the Hematopoietic Stem Cell Transplantation protocol.

Methods:

In this retrospective study, the medical records of patients treated between March 2016 and March 2022 were reviewed. A total of 29 patients with metastatic neuroblastoma received ¹³¹I-MIBG therapy before autologous Hematopoietic Stem Cell Transplantation. Treatment characteristics, post-therapy scan results, and survival data were analyzed.

Results:

The patients (n = 29) had a mean age of 47.9 ± 21.8 months at the time of treatment, with a mean interval of 9.5 ± 9.0 months between initial diagnosis and MIBG therapy. The average administered activity was 246.0 ± 64.4 mCi of ¹³¹I-MIBG. Sixteen patients (55.2%) were boys. Among the 25 patients with available post-therapy scans, 14 (53.8%) showed no residual MIBG uptake, 11 (42.3%) had persistent bone or bone marrow lesions, and 1 (3.8%) had uptake in the primary tumor site. All patients underwent Hematopoietic Stem Cell Transplantation within one month after MIBG therapy.

During a mean follow-up of 3.4 ± 1.7 years, 11 patients (37.9%) died, occurring at an average of 16.8 ± 14 months post-MIBG therapy. Four patients (13.8%) developed recurrence after an initial complete remission, and seven (24%) had persistent or remnant disease after transplantation. In total, 15 patients (51.7%) achieved sustained complete remission, while 3 patients were lost to follow-up.

Conclusion:

High-dose ¹³¹I-MIBG therapy followed by Hematopoietic Stem Cell Transplantation appears to be a feasible and effective option for selected patients with metastatic neuroblastoma. The absence of residual MIBG uptake on post-therapy scans correlated with improved survival, supporting its potential role as both a therapeutic and prognostic tool in pre-transplant conditioning regimens.