In radiation therapy, high energy x-rays or rays from radioactive substances, are aimed at a tumor causing damage to cancer cells which subsequently die because they cannot divide. Some non-cancerous cells near the tumor may also be damaged but the healthy cells will repair themselves.
Radiation is a special kind of energy carried by waves or a stream of particles.
It can come from special machines or from radioactive substances. When used at high levels, radiation can be used to treat cancer and other illnesses. Special equipment is used to aim the radiation at tumors or areas of the body where there is disease. The use of high-energy rays or particles to treat disease is called radiation therapy. It can also be called radiotherapy, X-ray therapy, cobalt therapy, electron beam therapy, or irradiation.