How Does Radiation Therapy Work?

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 divide more rapidly than many of the normal cells around them. Although some normal cells are affected by radiation, most normal cells appear to recover more fully from the effects of radiation than do cancer cells. Doctors carefully limit the intensity of treatments and the area being treated so that the cancer will be affected more than normal tissue.

What Are the Benefits & Goals of Radiation Therapy?

Radiation therapy is an effective way to treat many kinds of cancer in almost any part of the body. Half of all people with cancer are treated with radiation, and the number of cancer patients who have been cured is rising every day. For many patients, radiation is the only kind of treatment needed. Thousands of people are free of cancer after having radiation treatments alone or in combination with surgery, chemotherapy, or biological therapy.

Even when curing the cancer is not possible, radiation therapy still can bring relief. Many patients find the quality of their lives improved when radiation therapy is used to shrink tumors and reduce pressure, bleeding, pain, or other symptoms of cancer. This is called palliative care.