External Radiation Therapy

What Is Radiation Therapy? 

Cancer is a disease that causes cells to grow abnormally and out of control. In radiation therapy, high-energy X-rays are directed at a person's body to kill cancer cells and keep them from growing and multiplying.

Most people have been exposed to radiation in t he form of an X-ray — most likely at a dentist's office. And just like the X-rays given in the dentist's office, radiation therapy is painless. But unlike a typical X-ray, the radiation isn't used just to create a picture of a tooth or broken bone. Radiation therapy delivers higher doses of radiation so that the radiation will kill cancer cells and shrink tumors.

While it's killing the cancer, radiation therapy also can damage normal cells. The good news is that normal cells are more likely to recover from the effects of radiation. Doctors take precautions to protect a person's healthy cells when they're giving radiation treatments.