What is Radiation Therapy?

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 cannot.

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. Radiation therapy may be used along with, or in combination with chemotherapy and/or surgery. This depends on your type of cancer and the specifics of your disease.

Radiation therapy can be given in either two forms: external or internal. 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. The total dose of radiation and the number of treatments you need will depend on the size and location of your cancer, type of tumor, your general health, and any other treatments you are receiving.

When internal radiation therapy is used, a radioactive substance, or source, is sealed in small containers such as thin wires or tubes called implants. The implant is placed directly into a tumor or inserted into a body cavity.