Abstract
Radiation therapy is used for cure, control, and palliation of cancers in more than 60% of cancer patients. It is used alone as well as in combination with surgery and chemotherapy. The goal of radiotherapy is to treat the cancer and spare the normal tissue as much as possible. Advances have been made that allow delivery of higher doses of radiation to the tumor while sparing a greater amount of surrounding tissue, thus achieving more cures and fewer acute and long-term side effects. This article describes several of the new treatments along with the effects of radiation on the cells and tissues. Technological advances and research will continue to result in improvements in the field.