"Radiation has always been a little scary to me, but the fact that the technicians could stay in the room with me during treatment increased my comfort tremendously. And 5 days of treatment instead of the 33 I needed for my first lumpectomy? What a relief!"

— Sandra W.

How Does Radiation Therapy Work?

Radiation in high doses kills cells or keeps them from growing and dividing. Because cancer cells grow and divide more rapidly than most of the normal cells around them, radiation therapy can successfully treat many kinds of cancer. Normal cells are also affected by radiation. Electronic brachytherapy emits less radiation to healthy tissue and organs (see example).

Many people with cancer need radiation therapy. In fact, more than half of people with cancer get radiation therapy.*

Given in high doses, radiation kills or slows the growth of cancer cells. Radiation therapy is used to cure, stop or slow the growth of cancer. Radiation can also be used to reduce some symptoms or shrink cancer tumors.

Radiation therapy is often used with other cancer treatments. Here are some examples:

• Radiation therapy and surgery. Radiation may be given before, during or after surgery. Doctors may use radiation to shrink the size of the cancer before surgery, or they may use radiation after surgery to kill any cancer cells that remain. Sometimes, radiation therapy is given during surgery so that it goes straight to the cancer without passing through the skin. This is called intraoperative radiation.
• Radiation therapy and chemotherapy. Radiation may be given before, during or after chemotherapy. Before or during chemotherapy, radiation therapy can shrink the cancer so that chemotherapy works better. Sometimes, chemotherapy is given to help radiation therapy work better. After chemotherapy, radiation therapy can be used to kill any cancer cells that remain.

Resources

National Cancer Institute (Radiation Therapy for Cancer: Questions and Answers), accessed on October 9, 2009.