Questions about radiation therapy

What is radiation therapy?

Radiation (ray-dee-AY-shun) therapy (thair-uh-pee) is the use of radiation to treat cancer and other problems. There are different types of radiation. One that you may know about is x-rays. If you’ve ever had an x-ray of your chest or any other body part, you’ve had some radiation. Radiation is used in much higher doses to treat some types of cancer.

How does radiation therapy work?

Your body is made up of trillions of normal, healthy cells. Cancer starts when something changes a normal cell into a cancer cell. This cancer cell can then grow and make more cancer cells until a tumor is formed. Tumors can keep growing and cause problems. If the cancer is not treated, it can spread to other parts of the body and form more tumors.

Radiation is used to kill cancer cells. Special equipment sends high doses of radiation to the cancer cells or tumor. This keeps the cells from growing and making more cancer cells. Radiation can also affect normal cells near the tumor. But normal cells can repair themselves and cancer cells cannot.

Sometimes radiation is the only treatment needed. Other times it’s one part of a patient’s cancer treatment plan.

Your doctor may suggest radiation therapy to treat your cancer. Sometimes radiation can cure cancer. At other times the goal may be to slow the cancer’s growth to help you feel better. Be sure to talk to your doctor about the goal of your treatment.

Radiation therapy is not like chemotherapy (key-mo-THAIR-uh-pee, often called chemo). Radiation treats just the tumor. Chemo uses drugs to treat the whole body. So chemo might be used if a person has cancer in many places. Radiation affects only the part of the body being treated.

How much does radiation therapy cost?

Radiation therapy can cost a lot. How much yours will cost depends on the type of treatment you get and the number of treatments you need.

Most health insurance plans cover radiation therapy. Find out who can talk to you about your coverage and how much you will have to pay. Try to do this before you start treatment. If your income is low and you can get Medicaid, it will help pay for treatments.

If you do not have insurance or Medicaid, talk with your hospital’s social service office. Or call the American Cancer Society at 1-800-227-2345 to learn more about what help there might be for you.

The American Cancer Society medical and editorial content team
Our team is made up of doctors and master's-prepared nurses with deep knowledge of cancer care as well as journalists, editors, and translators with extensive experience in medical writing.

Last Medical Review: October 9, 2015 Last Revised: October 9, 2015

American Cancer Society medical information is copyrighted material. For reprint requests, please see our Content Usage Policy.