What is the difference between radiation therapy and chemotherapy?

Radiation therapy and chemotherapy are both types of treatment for cancer. Chemotherapy uses medications that are designed to kill or shrink growing cancer cells. Radiation therapy kills cancer cells by using beams of high energy, for example, x-rays or protons. Although they are very different types of treatment, they both share the same goals:

• Kill the cancer cells and prevent cancer from coming back.

• Prevent the spread of cancer to other parts of the body or slow the growth of tumors.

• Shrink tumor to relieve symptoms and/or lessen pain.

How Do They Work?

Chemotherapy uses medicines that travel through the blood, going throughout your body. It is called a “systemic” therapy because it can kill cells throughout your body, not just in one area of the body. Chemotherapy targets cells that grow and divide quickly. Cancer cells grow more rapidly than many healthy cells. Because of this, chemotherapy has a greater effect on cancer cells. However, the medicines are powerful and can damage healthy cells too. Chemotherapy is delivered as an infusion into a vein through an IV needle or port, by mouth in a pill or in an injection, like a shot would be given.

Radiation therapy uses high-energy beams instead of medicines. Radiation is a “local” treatment. This means that, unlike chemotherapy, it treats a specific area of the body where the cancer is located. Radiation therapy is delivered using a machine that produces high-energy beams directed at the tumor or internally with radioactive material placed inside your body, close to the tumor.

Which therapy is best for you?

The type of therapy that is best for you depends on the type of cancer and what stage of cancer you have. It is possible that you will need both chemotherapy and radiation therapy and may require surgery as well. Your health care team will determine the best course of treatment for you.