Radiotherapy and Regional Nodes

Comprehensive nodal irradiation to the axillary, supraclavicular, and internal mammary (IM) nodes is necessary in node-positive and certain high-risk patient populations. Since surgery or radiation are both effective in controlling microscopic regional node disease, radiation treatment (RT) is often provided only to the undissected nodal basins. Although IM nodal irradiation is controversial, recent evidence suggests that it confers a local control and survival advantage. In the post-mastectomy setting, chest wall and comprehensive nodal irradiation is standard for patients with T4 disease and ≥4 axillary nodes involved, but randomized studies and meta-analysis data strongly suggest that post-mastectomy radiation therapy (PMRT) benefits patients with any number of nodes involved. Patients with high-risk disease undergoing upfront neoadjuvant chemotherapy also may benefit from comprehensive nodal radiation after surgery, but this data is currently maturing.