Demonstration of a Novel Approach Using Surface-Image Guidance to Improve Delivery of Breast Radiotherapy

Inclusion Criteria: * Age ≥ 18 years * Biologically female * Ability to provide informed written consent in either English or Spanish * Surgical pathology and staging scans must demonstrate Ductal carcinoma in situ (DCIS) or invasive breast cancer, Stages 0, 1, 2, and 3 * Patient will undergo adjuvant radiation therapy as a part of multimodality breast cancer treatment with plans for tangent field radiation treatment with or without loco-regional lymph node targeting, based on the clinical judgement of the treating physician * Willingness to maintain temporary skin markings for a part of their of radiation therapy duration * Absence of any conditions that may affect ability to have either tattoos or skin markings, as discussed in Exclusion Criteria Exclusion Criteria: * Age \< 18 years * Biologically non-female * Inability or unwillingness of subject to give written informed consent * Patients found at presentation to have very locally-advanced cancer (e.g. inflammatory breast cancer) or metastatic breast cancer (Stage 4) * Patients that will be treated with a deep-inspiration breath hold technique (typically younger patients being treated for left-sided tumors) * Current pregnancy, as this is a contraindication to receiving radiation therapy * History of prior radiotherapy to the chest wall or torso * Known allergy / sensitivity to standard medical marking tattoo ink (by design non-toxic, low-allergy), skin marking paint, or medical tape (e.g. Tegaderm) * Active drug or alcohol use or dependence evidenced by patient record and/or self-report that, in the opinion of the investigator, would interfere with adherence to daily radiation therapy