Radiation therapy

Radiation therapy involves using high-powered X-rays or gamma rays (XRT) that precisely target the area being treated. These X-rays or gamma rays are very effective in destroying the cancer cells that might recur where the tumor was removed. The X-rays are delivered by a machine called a linear Accelerator or LINAC. Alternatively, the use of implanted radioactive catheters (brachytherapy), similar to those used in prostate cancer treatment, is being evaluated. Radiation therapy for breast cancer is usually performed after surgery and is an essential component of breast-conserving therapy. The purpose of radiation is to reduce the chance that the cancer will recur.

Radiation therapy eliminates the microscopic cancer cells that may remain near the area where the tumor was surgically removed. The dose of radiation must be strong enough to ensure the elimination of cancer cells. However, radiation affects normal cells and cancer cells alike, causing some damage to the normal tissue around where the tumor was. Healthy tissue can repair itself, while cancer cells do not repair themselves as well as normal cells. For this reason, radiation treatments are given over an extended period, enabling the healthy tissue to heal. Treatments are typically given over a period of five to seven weeks, performed five days a week. Each treatment takes about 15 minutes.

Although radiation therapy can reduce the chance of breast cancer recurrence, it is much less effective in prolonging patient survival. According to a review of six studies by the National Cancer Institute, none of them found a survival benefit for radiation therapy. Patients who are unable to have radiation therapy after lumpectomy should consult with a surgeon who understands this research and who believes that lumpectomy (or partial mastectomy) alone is a reasonable treatment option.