External Hypofractionated Radiotherapy With Simultaneous Integrated Boost in Early Breast Cancer Patients

Inclusion Criteria: * Histologically proven invasive or in situ unifocal adenocarcinoma of the breast * Breast conserving surgery * Pathological pTis G3, pT1-2 any Grade, pN0 or pN0(sn) (isolated tumor cells \[i+\] allowed) pN1mic, M0 stage * Postoperative negative (no ink) final surgical margins * Patient requires a whole breast radiotherapy plus a tumor bed boost * Female patients aged ≥ 18 years of any menopausal status * ECOG performance status 0-2 Exclusion Criteria: * Past history of malignancy except basal cell skin cancer and CIN cervix uteri or non-breast malignancy allowed if treated with curative intent and at least 5 years' disease free * Mastectomy * Concomitant chemotherapy (primary or sequential chemotherapy allowed) (Chemotherapy and radiotherapy must be separated by a minimum of 2 weeks). (Patients receiving neo-adjuvant chemotherapy are not excluded) * Known disorders associated with a higher risk for complications following radiotherapy such as collagen vascular disease, dermatomyositis, systemic lupus erythematosus or scleroderma * Any psychological, familiar, sociological or geographical condition potentially hampering compliance with the study protocol and follow-up schedule * Any serious uncontrolled medical disorder, non-malignant systemic disease, or active uncontrolled infection. Example include but are not limited to uncontrolled ventricular arrhythmia, recent (within 3 months) myocardial infarction or uncontrolled major seizure disorder * Pregnant or lactating patients * Presence of ipsilateral breast implant * Prior breast or thoracic radiotherapy for any condition