[Radiotherapy: Therapeutic and aesthetic issues]

Radiotherapy is a major pillar of breast cancer treatment, aimed at reducing local recurrence and improving survival while preserving quality of life. It is often administered after conservative surgery, and in some cases post-mastectomy for high-risk patients. Techniques and indications have evolved, including approaches such as intensity-modulated conformal radiotherapy (IMRT) for greater precision and reduced side effects. (1) General: radiotherapy reduces the risk of local recurrence (35% to 19.3% after conservative surgery) and improves overall survival, particularly in patients with lymph node involvement (pN+). Modern approaches favor the reduction of axillary curage in favor of sentinel lymph node detection, limiting morbidity. (2) Specific indications: after total mastectomy, radiotherapy is recommended according to risk factors (stage, margins, age). Different irradiation protocols are available, with hypofractionated regimens becoming the standard. (3) Breast reconstruction and radiotherapy: immediate breast reconstruction combined with radiotherapy requires careful planning to minimize complications. (4) Reverse sequence: this innovative approach, involving preoperative radiotherapy prior to mastectomy, is designed to improve aesthetic results and tumor control. Although promising, it requires further study. (5) Merkel carcinoma and oligometastases: radiotherapy is essential in the treatment of Merkel carcinoma, significantly reducing the risk of recurrence. For oligometastases, stereotactic radiotherapy is emerging as an effective option for precisely targeting metastases, with good local control rates and few side effects. Radiotherapy continues to evolve, integrating advanced technologies to optimize cancer treatment while reducing the associated side effects.