ARPEGE biomarqueurs is a prospective multicenter study to prospectively evaluate with this assay the RS of children and adolescents treated over a year in all pediatric oncology departments of the Region Grand Est and set thresholds in this population. 150 children are thus potentially includable in different centers. The assay will be performed on primary fibroblasts cultured from a skin biopsy taken at diagnosis. The RS of patients will be measured in blind. Confusion factors such as irradiated volume, skin phototype, previous chemotherapy regimen, smoking, comorbities (diabetes, immunodeficiency, chronic inflammatory disease ...) will be reported. In parallel the RT-acute toxicity will be reported according to NCI-CTCAE v4.0 reference scale three months of the completion of RT then periodically during 15 years.