Risk-adapted radiotherapy after breast-conserving surgery: Current standards and future developments

Radiotherapy is a cornerstone of breast cancer treatment. While adjuvant radiotherapy after breast-conserving surgery (BCS) used to be a one size fits all-approach, this has dramatically changed during the past decades. Due to the excellent outcomes of multi-disciplinary treatment for patients with early-stage low risk breast cancer, many efforts in clinical research focus on de-escalation. Regarding many of these efforts have focused on omission of WBI. This article focusses on treatment principles, contemporary and future approaches of individualized, risk-adapted radiotherapy after BCS with a focus on de-escalation and risk-adapted radiotherapy. Regional nodal irradiation and post-mastectomy radiotherapy are beyond the scope of this manuscript.