RATIONALE: Radiotherapy (RT) can be indicated to patients submitted to breast-conserving surgery, but, despite the benefits, adjuvant RT can cause contracture generated by tissue fibrosis in patients with immediate prosthetic reconstruction, which could cause prosthesis loss. The biological explanation of this outcome is not fully understood, but recent advances in the analysis of patient-derived blood can contribute to establishing a connection of molecular alterations related to this clinical outcome. There is not a consensus about using hypofractionated RT schemes for patients with BCS and breast reconstruction since no studies had investigated the reasons why some patients lose the prosthesis. PURPOSE: This study will evaluate G3 toxicity rate in breast cancer patients with immediate prosthetic reconstruction, submitted to hypofractionated radiotherapy, analyzing capsular contracture, leakage, infection, and bad positioning in order to demonstrate the noninferiority of Hypo-RT with the conventional RT. Additionally, the molecular profile of blood samples will be investigated in order to find biomarkers related to inflammations processes and response to treatment.