[123I]-metaiodobenzylguanidine imaging findings and outcome in patients with metastatic neuroblastoma

Background: 123I-Metaiodobenzylguanidine ([123I]mIBG) is the agent of choice to assess for presence of metastases and therapy response in patients with neuroblastoma.Aim: To assess [123I]mIBG scan results and outcome in patients with stage 4 neuroblastoma at our institution.Setting: Red Cross War Memorial Children’s Hospital.Methods: A retrospective review of baseline and follow-up [123I]mIBG scans of patients who presented between January 2001 and May 2015. The clinical follow up extended until October 2019. The association between the baseline and post-induction Curie score (CS) and overall survival (OS) were assessed.Results: Thirty-four patients with stage 4 disease were included. Twenty-two (65%) patients died. The median age at diagnosis for survivors was 15.5 months vs 39 months for those who died (Kruskal Wallis c2 = 4.63, p = 0.03). Neither the baseline CS nor the post-induction CS predict the outcome or duration of survival. The median OS for a baseline CS ≤ 12 and CS 12 was 19 and 26 months, p = 0.13. The median OS for a post-induction CS 2 and CS ≤ 2 was 28 and 26 months, p = 0.66.Conclusion: In this study, baseline, post-induction and reduction in CS did not predict OS in stage 4 neuroblastoma. Factors such as small patient numbers, less intensive treatment regimes, and possible poorly dedifferentiated disease have been identified for this finding.Contribution: In contrast to international studies the Curie score did not predict treatment outcome in the South African setting where the vast majority of patients are treated with OPEC/OJEC OPEC/OJEC (vincristine [O], cisplatin [P], etoposide [E], cyclophosphamide [C] and carboplatin [J]) chemotherapy.