Study population: We chose 3 models of pediatric solid tumors with high risk of metastases and which often require sterilizing treatments (chemo and/or radiotherapy): neuroblastoma, Ewing tumor and alveolar rhabdosarcoma. We will use four tumor cells lines: IMR32 and SK-NSH for neuroblastoma; RD-ES for Ewing tumor; RH-30 for rhabdosarcoma. We plan to use 20 fragments per line.