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