Single-center phase 2 trial of postoperative single fraction stereotactic partial breast irradiation with GammaPod for early-stage breast cancer

GammaPod is a novel stereotactic radiotherapy device. A phase 2 trial at the Santa Maria della Misericordia Hospital (Udine, Italy) evaluated postoperative single fraction stereotactic partial breast irradiation (S-PBI) using GammaPod for early-stage breast cancer. The study included 148 patients who received breast-conserving surgery followed by S-PBI (17.5 Gy). The median time from surgery to radiation was 2.5 months (IQR 2.1-2.9). Median follow-up was 24.9 month. Grade 2 fibrosis occurred in 3.3% of patients; there were no grade ≥ 3 toxicities. Local recurrence, regional recurrence, and locoregional recurrence rates at 24 months were 1.8%, 0.8%, and 1.8%, respectively. The authors conclude that single-fraction S-PBI using GammaPod was associated with excellent tolerability and promising early oncologic control in early-stage breast cancer.