When someone faces a diagnosis of cancer, radiation therapy is frequently part of his or her treatment. Cancer cells are highly abnormal cells, and are particularly sensitive to the high-energy radiation techniques that we use today. Cancer cells are in a way "broken" cells - they have forgotten how to function properly and they can't get back on track. Radiation treatments cause more changes in these broken cells, so that the cells can no longer grow or maintain themselves and they slowly die off. The patient's own immune system clears those dead cells away.

Fortunately, our normal cells are much better at tolerating radiation. Most normal cells in a radiated area stay healthy. Some normal cells are damaged, but the surrounding healthy ones support or replace them. We use a variety of techniques to try to maximize the damage to cancer cells and minimize damage to normal cells. We use excellent imaging techniques like CT, MRI and PET scans to define the "target" as well as possible. We can also use small beams from many directions to shape radiation to the cancer and avoid the surrounding normal tissue.

So while all anti-cancer treatments have possible adverse effects, radiation treatment is usually well tolerated.

Thyra Endicott, MD
Diplomate, American College of Radiology, Specialty of Radiation Oncology
Assistant Clinical Professor, UCLA
Member, South Bay Independent Physicians Medical Group, Inc.