NCCN Guidelines Update: Evolving Radiation Therapy Recommendations for Breast Cancer.

In the NCCN Clinical Practice Guidelines in Oncology (NCCN Guidelines) for Breast Cancer, among adjuvant radiotherapy options for whole-breast irradiation after breast-conserving surgery, hypofractionation is preferred. For the use of accelerated partial-breast irradiation, the NCCN Guidelines have adopted the updated definition of "suitability" used by the American Society for Radiation Oncology. Regional nodal irradiation is indicated-either in the setting of breast-conserving surgery or after mastectomy-for women with ≥4 positive nodes and should be strongly considered for 1 to 3 positive lymph nodes and select patients with node-negative disease deemed at high risk for recurrence.