Predictive Toxicity Test Linked to Radiotherapy After Mastectomy and Immediate Implant Reconstruction

Inclusion Criteria: * Age ≥18 years * Patients with histologically confirmed breast cancer with indication of mastectomy or surgery with mastectomy performed * Indication of wall chest radiation after mastectomy * Patient's agreement to receive or having had an immediate breast reconstruction by implant in one or two steps, with or without a dermal or synthetic matrix (depending on the habits of the center) * Performance Status 0-1 * Consent signed before any study procedure * Patient geographically accessible for follow-up * Affiliated to the French national social security system Exclusion Criteria: * Breast reconstruction with flap * Inflammatory breast cancer (cT4d) * Skin or parietal breast cancer (cT4 a, b or c) * Metastatic patients * Patients with bilateral breast cancer * History of homolateral breast cancer treated with radiotherapy * History of contralateral breast cancer * Pregnant or breastfeeding women * Legal incapacity or physical, psychological or mental status interfering with the patient's ability to sign the informed consent * Participation in an interventional clinical study or planned participation during study up to 12 months post-radiotherapy