Radiation therapies for breast cancer: current knowledge on advantages and disadvantages.

Radiation therapy continues to be the most effective adjunct to surgery to achieve long-term local control of breast cancer. In this respect it is more effective than both adjuvant cytotoxic therapy and adjuvant tamoxifen. Radiation therapy therefore plays an important role in the primary management of selected groups of breast cancer patients. However, radiation therapy may be related to potentially serious side effects, including ischemic heart disease and pneumonitis. After breast-conserving surgery radiation therapy may also compromise the cosmetic outcome. An appropriate treatment technique and avoidance of excessive treatment is essential to decrease the risk of adverse side effects. Concomitant administration of chemotherapy should probably be avoided, as well as treatment schedules with single fractions in excess of 2 Gy.