Hypofractionated vs Conventional RT After Prosthetic Breast Reconstruction

Inclusion Criteria: * Female, aged 18-75 years * Karnofsky Performance Status ≥60 * Histopathologically confirmed invasive breast adenocarcinoma * Total mastectomy \[with or without nipple-areolar complex preservation\] + axillary dissection/sentinel lymph node biopsy + implant/expander placement R0 resection with negative margins * pT3 or N2-3 disease; or pT1-2N1 * No distant metastasis * Completed standard neoadjuvant/adjuvant chemotherapy cycles * ≤8 weeks post-chemotherapy or ≤12 weeks post-surgery if no chemotherapy * Signed informed consent Exclusion Criteria: * Prior radiotherapy to chest wall or nodal regions * Pregnancy or lactation * T4 stage disease * Autologous breast reconstruction of the irradiated breast * Pre-radiotherapy local/regional/distant metastasis * Grade ≥3 implant-related adverse events irreversible before radiotherapy * Bilateral breast cancer requiring bilateral radiotherapy * Concurrent/secondary malignancy with disease-free interval \<5 years \[except non-melanoma skin cancer, papillary/follicular thyroid cancer, or cervical carcinoma in situ\] * Active collagen vascular disease, e.g., SLE, scleroderma * Uncontrolled comorbidities: acute cardiovascular disease, substance abuse, or psychiatric disorders