Radiation therapy, or radiotherapy, is the use of radiation to safely treat and manage cancer. Radiation oncologists use radiation to eradicate cancer cells, reduce their growth or relieve symptoms of cancer.
Radiation therapy treats cancer by damaging cancer cells while limiting the impact to healthy cells. It works because cancer cells are more sensitive to radiation than healthy, normal cells. When a small dose of radiation is given each day over several weeks, normal cells can recover from the radiation, but cancer cells cannot.
Radiation therapy is typically a painless treatment, similar to having an x-ray, and is only delivered to the part of the body being treated.