This is a multicenter, prospective, randomized phase 3 trial. Patients with node-positive breast cancer without distant metastases were included. All patients underwent breast conservation surgery or mastectomy with axillary lymph node dissection before irradiation. Patients underwent regional nodal irradiation along with breast or chest wall irradiation and randomly allocated to either IMNI or no IMNI.
The aim of this study is to find out whether the inclusion of internal mammary node irradiation in regional nodal irradiation improves outcomes in women with node-positive breast cancer.