Inclusion Criteria:  Age 18 years and older ECOG performance status 0-2 Ability to understand and willingness to sign a written informed consent document Stage pT1-3, pN0-3, M0 histologically proven breast cancer no matter the status of ER/PR/HER2 receptor testing Managed with either mastectomy or breast conserving surgery Suitable for radiation therapy to the breast/chest wall and regional lymph nodes Neoadjuvant and adjuvant systemic therapy with chemotherapy, endocrine therapy and anti-HER2 therapy is accepted Neoadjuvant radiotherapy (reverse sequencing) accepted Breast implants and expanders are accepted Patients with connective tissue disease are allowed if the treating radiation oncologist finds radiation therapy indicated Life expectancy minimum 10 years Patients with non-breast malignancies are accepted if the patient has been disease free for five years and/or has a low risk of recurrence as estimated by the treating radiation oncologist (to be determined at initial patient appointment)  Exclusion Criteria:  Prior radiotherapy to the ipsilateral breast or chest wall Pregnancy or lactation Radiosensitivity syndrome Permanent pacemaker/defibrillator within radiotherapy field Oncoplastic surgery where boost volume unacceptable (clinician discretion) Conditions indicating that the patient cannot go through radiation therapy or follow up, or a condition where the treating oncologist thinks the patient should not participate in the trial (for example, language barriers)