NeoRad Breast Cancer Study

Inclusion Criteria:

• Histologically proven invasive, unilateral breast cancer

• Indication for radiotherapy

• Indication for neoadjuvant chemotherapy (+/- antibody treatment or other targetedtherapies) in accordance with national and international guidelines

• Female

• Informed consent for the trial signed by the patient

• Hormone receptor and HER2 status: no restrictions

• All grades G1-G3

• Age ≥ 18 years at the time of informed consent

• Performance status ≤ 2

• No pre-existing conditions that prohibit therapy

Exclusion Criteria:

• Neoadjuvant treatment solely with endocrine therapy

• Bilateral breast cancer

• Pregnancy or lactation

• Prior radiotherapy of the thorax

• Connective tissue disease, including rheumatoid arthritis and thromboangiitisobliterans

• Pre-existing symptomatic chronic lung disease (fibrosis, pneumoconiosis, adult-onsetallergies, such as farmer's lung, severe lung emphysema, COPD °III)

• Cardiac comorbidities: symptomatic coronary heart disease, prior heart attack, heartfailure NYHA ≥II or AHA ≥C, pacemaker, and/or implanted defibrillator

• Malignoma except basalioma or in-situ-carcinomas in complete response

• Distant metastasis

• Plexopathies of the arm of the treated side

• Stiffness of the shoulder of the arm of the side of the breast cancer of any origin (e.g. following a road accident)

• Lymph edema ≥°II of the arm at the side of the breast cancer

• Other medical conditions that prohibit the neoadjuvant radiotherapy (i.e. Expectednon-compliance, etc.)

• Male patients

• Patients who have previously been assessed for chemotherapy response