Image Guided Radiotherapy (IGRT) for Prone Partial Breast Irradiation

IGRT for prone partial breast irradiation (PBI): All patients will be treated prone with 6 Gy/fraction delivered in 5 fractions over a 1-week period for a total dose of 30 Gy. Simulation and treatment will be started within 50 days from surgery in order to maximize the chances of optimal lumpectomy cavity visualization on the planning and cone beam CT scans. All patients will be followed monthly for the first 90 days then q3 months for the first year, then yearly for the next 10 years.