Postoperative Radiation of Patients With Breast Cancer in Extreme Hypofractionation.

Postoperative External Beam Whole Breast or Chest Wall Irradiation of Patients With Breast Cancer in Extreme Hypofractionation.

Evaluation of treatment toxicity of extreme hypofractionation of the whole breast in five fractions of 5.2 Gy in five consecutive workdays.

The focus of this phase 2-trial is set on feasibility as well as early and late toxicity rates. One possible disadvantage of extreme hypofractionation could be an increased rate of fibrosis within the irradiated region. Therefore, a closer look will be taken with this prospective trial.

In addition, we are planning an accompanying translational research program since hypofractionated schedules are suggested to be more immunogenic in breast cancer.

Secondary objectives therefore are: cosmetic outcome, local tumor control, quality of life, dynamic immune status, importance of tumor infiltrating immune cells, overall survival, disease-free survival, feasibility of breath-hold radiation technique.

Inclusion Criteria:

• Histologically confirmed invasive breast cancer or ductal carcinoma in situ (DCIS)
• pT-category pT0-3
• complete resection (R0)
• Absence of distant metastasis (M0)
• Absence of contralateral breast cancer/ DCIS
• Karnofsky Performance Score ≥ 60%
• Age ≥ 18 years at time of study entry
• Written informed consent

Exclusion Criteria:

• All patients not fulfilling inclusion criteria
• Morbus Paget or pathological skin infiltration
• Earlier or synchronous breast cancer
• Pregnant or breast-feeding women
• Increased radiosensitivity or any genetic disposition for increased radiosensitivity, e.g. ataxia telangiectatica
• Judgement by the investigator that the patient is unlikely to comply with study procedures and requirements