Feasibility and effectiveness of treatment strategy of tandem high‐dose chemotherapy and autologous stem cell transplantation in combination with 131I‐MIBG therapy for high‐risk neuroblastoma

Abstract This study was performed to evaluate the safety and effectiveness of tandem HDCT/ASCT combined with targeted radiotherapy using 131 I‐MIBG for high‐risk neuroblastoma. Patients with high‐risk neuroblastoma were treated with 8 to 10 cycles of induction chemotherapy before tandem HDCT/ASCT. Patients received 131 I‐MIBG treatment before the second HDCT/ASCT. Local radiotherapy and maintenance therapy were performed after tandem HDCT/ASCT. Between 2012 and 2016, 19 patients were diagnosed with high‐risk neuroblastoma in our institution and 18 of them received tandem HDCT/ASCT combined with 131 I‐MIBG therapy. For the first HDCT/ASCT regimen, 12 patients received busulfan/melphalan and six patients received melphalan/etoposide/carboplatin. The second HDCT included ThioCy. The median dose of 131 I‐MIBG was 17.2 mCi/kg for the first eight patients, while 12 patients in the latter period of the study received reduced dose of 10.7 mCi/kg. The 5‐year OS and EFS rates were 79% and 61%, respectively, for all 19 patients with high‐risk neuroblastoma, and 83% and 64%, respectively, for 18 patients who completed tandem HDCT/ASCT combined with 131 I‐MIBG therapy. Six patients experienced disease relapse and five patients died. Treatment‐related mortality was not observed. Among 15 evaluable patients, 11 patients (73%) developed hypothyroidism, six patients (40%) had CKD, and six patients (40%) had growth failure. Hypothyroidism and growth failure were less frequent in patients who received reduced doses of 131 I‐MIBG therapy. Tandem HDCT/ASCT combined with HD 131 I‐MIBG therapy could be feasible for patients with high‐risk neuroblastoma with acceptable toxicity profiles and favorable outcomes.