NeoRad Breast Cancer Study

Inclusion Criteria: * Histologically proven invasive, unilateral breast cancer * Indication for radiotherapy * Indication for neoadjuvant chemotherapy (+/- antibody treatment or other targeted therapies) 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 thromboangiitis obliterans * Pre-existing symptomatic chronic lung disease (fibrosis, pneumoconiosis, adult-onset allergies, such as farmer's lung, severe lung emphysema, COPD °III) * Cardiac comorbidities: symptomatic coronary heart disease, prior heart attack, heart failure 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. Expected non-compliance, etc.) * Male patients * Patients who have previously been assessed for chemotherapy response