This is an international, multicenter, open-label, randomized, Phase 3 study in patients withlocally advanced, inoperable or metastatic triple-negative breast cancer (TNBC) who have not received previous therapy for advanced disease and whose tumors are either: PD-L1 negative at screening (defined using the PD-L1 IHC 22C3 assay as tumors with a combined positive score (CPS) < 10), OR PD-L1 positive at screening (defined using the PD-L1 IHC 22C3 assay as tumors with a CPS ≥ 10) if they previously received a checkpoint inhibitor in the adjuvant or neoadjuvant setting.

The first goal of this project is to validate the superiority of semi-permanent marks used in conjunction with specialized light-based surface imaging (SIGRT) in an effort to phase out the use of permanent tattoos for the investigator's patients. The secondary goal of this project is to validate the superiority of specialized light-based surface imaging for daily radiation set-up compared to standard-of-care imaging methods using ionizing radiation, such as weekly port films or cone-beam CT (CBCT) scans during a radiation therapy course for breast cancer.

This randomized phase III trial studies standard or comprehensive radiation therapy in treating patients with early-stage breast cancer who have undergone surgery. Radiation therapy uses high-energy x rays to kill tumor cells. It is not yet known whether comprehensive radiation therapy is more effective than standard radiation therapy in treating patients with breast cancer