This is an international multicenter, open-label, randomized phase III trial including three sequential randomizations to assess efficacy of induction and consolidation chemotherapies and radiotherapy for patients with high-risk neuroblastoma.

The first randomization (R-I) will compare the efficacy of two induction chemotherapies (RAPID COJEC and GPOH regimens) in a phase III setting. The primary endpoint will be the 3-year EFS from date of randomization . The R-I randomization will be stratified on age, stage, MYCN status and countries.

The second randomization (R-HDC) will compare the efficacy of single HDC with Bu-Mel versus tandem HDC with Thiotepa followed by Bu-Mel. The primary endpoint is 3-year EFS calculated from the date of the R-HDC randomization. The R-HDC randomization will be stratified on the age, stage, MYCN status, induction chemotherapy regimen, response to induction phase and countries.

The impact of local treatment in this phase III setting will be assessed, according to the presence or not of a macroscopic residual disease after surgery and HDC.

In case of macroscopic residual disease, 21.6 Gy radiotherapy to the preoperative tumor bed will be randomized (R-RTx) versus the same treatment plus a sequential boost of additional 14.4 Gy to the residual tumor. The primary endpoint of R-RTx is 3-year EFS from the date of the R-RTx randomization. The R-RTx randomization will be stratified on age, stage, MYCN status, induction chemotherapy regimen, HDC regimen and countries.

In case of no macroscopic residual disease, 21.6 Gy radiotherapy will be delivered to the preoperative tumor bed.