Definition Radiation therapy is the use of high energy rays or particles to treat disease. High doses of radiation can kill cells or keep them from growing and dividing. Radiation therapy is a useful tool for treating cancer because cancer cells grow and divided more rapidly than many of the normal cells around them. All cells in the area are affected, but repeated exposure to a small amount of radiation over a period of time allows healthy cells to recover, while diseased cells can not.
Radiation therapy is an effective way to treat many kinds of cancers in almost any part of the body.
More than half of all people with cancer are treated with radiation, and the number of patients who have been cured is rising every day. This depends on your type of cancer and the specifics of your disease. In external therapy, a machine directs the high-energy rays or particles at the cancer and the normal tissue surrounding it. Most people who receive radiation therapy for cancer have the external type. Typically, external radiation treatment is given 5 days a week over 4-7 weeks.