Hypofractionation With Simultaneous Integrated Boost vs. Standard Fractionation in Early Breast Cancer

Inclusion Criteria: * Histopathologically confirmed breast cancer operated by breast conserving surgery with clear margins independently of further risk factors (positive or high-risk negative lymph node status, estrogen- or progesterone receptor status, Her-2/neu status uPA/PAI-1 criteria) and postoperative systemic therapy (chemotherapy, endocrine, antibody or bisphosphonate therapy were permitted when indicated) * Indication to adjuvant radiotherapy including boost radiotherapy * Clearly identified primary tumor region preferably by radiopaque clips * Primary wound healing after breast conserving therapy without signs of infection * Age ≥ 18 years * ECOG ≤ 2 Performance Status * Written informed consent * Compliance regarding treatment appointments and toxicity * Linguistic and cognitive ability to understand the questionnaires Exclusion Criteria: * Patients operated by mastectomy * No indication for boost radiation (e.g. status after IORT) * double sided breast cancer * Resection margins positive for disease or insufficient identification of the boost volume * Indication for radiotherapy of the regional lymph nodes * History of prior breast or thoracic radiotherapy * Extended postoperative seroma at the beginning of radiotherapy * Previously administered radiotherapy not allowing the required dose * Pregnant or lactating patients and woman of child bearing potential, who lacked effective contraception * treatment history of other cancer or participation in another clinical trial testing radiotherapy or drugs within 4 weeks of the start of treatment. * Patients with serious, uncontrolled, physical or cerebrovascular disorders(e.g. myocardial infarction within the last 12 months) or neurologiy or psychiatric disorders thought to adversly affect treatment compliance