Radiation therapy (sometimes called radiotherapy) uses high energy radiation to treat cancer. Radiation therapy can be used to cure cancer, either on its own, or in combination with other cancer treatments such as chemotherapy or surgery. Radiation can also be used to help manage symptoms of cancer that may affect the quality of your life. Radiation therapy works by killing or causing damage to cancer cells. It can destroy them outright, or it can prevent them from growing and multiplying. Radiation therapy can also damage healthy cells surrounding the cancer cells, but these cells are able to recover. Radiation therapy is localised, which means it generally only affects the part of the body where radiation is directed.