Why might I need radiation after breast cancer surgery?

After undergoing a lumpectomy to remove the part of the breast affected by breast cancer, most women must undergo radiation therapy treatments to eliminate microscopic cancer cells that might remain undetected by clinical examination or breast imaging in order to decrease the risk of local recurrence. The standard course of breast irradiation delivers radiation to the entire breast, and consists of six to seven weeks of therapy given five days a week. Some patients may be candidates for shorter courses of radiation or partial breast radiation.