Radiation Treatment in Breast Cancer

The optimal treatment for breast cancer (BC) needs a multidisciplinary team approach. Whole breast irradiation (WBI) is the standard of care after breast-conserving surgery (BCS) and selected patients with risk factors after mastectomy need postmastectomy radiotherapy (PMRT). Several randomized trials demonstrated noninferior oncological outcomes with hypofractionated regimes without increasing the toxicity in early BC compared with the conventional fractionation and in recent years, WBI with hypofractionated schedules replaced conventional fractionation with the advantage of shortening treatment duration and improving patient compliance. The decision for adjuvant PMRT depends on the clinical stage, response to neoadjuvant chemotherapy when applied, and the presence of residual disease. The axillary lymph node (LN) status is the most important prognostic factor in patients with BC. Although the standard approach is axillary lymph node dissection (ALND) in patients with positive sentinel lymph node biopsy (SLNB), there is an increasing trend in replacing ALND with radiotherapy (RT) to reduce lymphedema, especially in low-risk patients. Since the survival rates are increasing in parallel to the advancements in BC treatment, the prevention of adverse effects of the treatment has become crucial. Lymphedema, brachial plexopathy, cardiac toxicity, pneumonitis, and secondary cancers are the most threatening adverse effects in a long-term follow-up but with modern modern RT techniques, the incidence of severe late side effects is very rare.