Breast Cancer With Intraoperative Radiotherapy Followed by Hypofractionated External Beam Radiotherapy

Inclusion Criteria: * Histologically-confirmed diagnosis of invasive breast carcinoma and eligibility for conservative surgery (with or without oncoplastic surgery) and radiotherapy. * Not pregnant at diagnosis. * Signed informed consent form. * Age ≥45 years old. * Patients candidates to Intrabeam. * Patients with ≥60 years with the presence of one or more of the following adverse criteria after surgery: * Tumor size \> 2.5 cm. * Extensive intraductal carcinoma (≥25%) * Lymphovascular invasion. * Involved focal margins (\<2mm) without ampliation surgery. Exclusion Criteria: * Presence of distant metastasis. * Primary chemotherapy. * Lymph node involvement. * Negative hormonal receptors. * Diagnosis of any other infiltrating tumour except for adequately resected squamous or basal cell epitheliomas * Patients with collagen vascular disease (systemic lupus erythematosus, scleroderma, dermatomyositis). * Uncontrolled infection. * Concurrent treatment with other experimental treatments * Lack of signed informed consent form.