Management of neuroblastoma. Comparative study between first- and second-line radioionated meta-iodobenzylguanidine therapy and chemotherapy alone

Context: Neuroblastoma is a high-grade malignancy of childhood; it is chemo- and radio-sensitive, but prone to relapse after initial remission. Aim : The aim of this study was to document the impact of first- or second-line radioionated [ ¹³¹ I] meta-iodobenzylguanidine ( ¹³¹ I-MIBG) therapy or chemotherapy alone on the short-term response and long-term survival in untreated children and to further characterize the side-effects of MIBG treatment. Materials and Methods: In this interventional randomized controlled study, 123 children with advanced neuroblastoma were divided into three groups according to the treatment strategy: 65 were treated by chemotherapy alone (group I), 30 children who were not responding or had relapsed after chemotherapy were treated by second-line ¹³¹ I-MIBG (group II), and 28 children were treated by ¹³¹ I-MIBG as first-line from the start (group III). External beam radiotherapy was given to bone and brain secondaries when detected. Staging work up was done before, during, and after management with a follow-up period of 5 years. Statistical Analysis Used: All statistical tests were done using Whitney test for the continuous variants to compare the same group pre- and post-therapy. Total actuarial survival and disease-free survival were calculated using Kaplan-Meier analysis. Results: The number of treatments with ¹³¹ I-MIBG varied between 1 and 4 per patient (mean 3). Toxicity was seldom severe. Mainly myelosuppression was noticed. Response was documented before surgery for the primary tumor was performed. There was 9, 6, and 14 complete response (CR); 10, 18, and 16 partial responses (PR); 3, 2, and 23 with a stable disease (SD); and 6, 4, and 12 progressed in each group, respectively. Total actuarial survival was found to have a median of nearly 60, 55, and 33 months for groups I, II, and III, respectively, with a statistical significant difference between the three groups. Conclusion: The current study showed the effectiveness of MIBG as a first-line treatment in the management of locally advanced neuroblastoma cases with limited metastasis as initial response and long-term survival for the cases was favorable, while in cases with multiple metastases, chemotherapy should be given first-line and, in case of failure or relapse, second-line MIBG therapy is warranted.