Radiation therapy is controlled use of radiation to stop the growth of cancer cells.
Cancer cells are more susceptible to radiation than normal cells.
About half of cancer patients have radiation therapy at some point in their treatment. In some types of cancer, radiation therapy is used for cure. Hodgkin's disease and certain kinds of tumors of the testicles, head, neck, and uterine cervix are some of the cancers that can be cured with radiation. Radiation therapy may be used to control the spread of a cancer when a tumor cannot be removed by surgery. Or it may be used to control the symptoms of a cancer that has spread.