What does radiation therapy do to healthy cells?
Radiation not only kills or slows the growth of cancer cells, it can also affect nearby healthy cells. The healthy cells almost always recover after treatment is over. But sometimes people may have side effects that do not get better or are severe. Doctors try to protect healthy cells during treatment by: • Using as low a dose of radiation as possible. The radiation dose is balanced between being high enough to kill cancer cells yet low enough to limit damage to healthy cells. • Spreading out treatment over time. You may get radiation therapy once a day for several weeks or in smaller doses twice a day. Spreading out the radiation dose allows normal cells to recover while cancer cells die. • Aiming radiation at a precise part of your body. New techniques, such as IMRT and 3-D conformal radiation therapy, allow your doctor to aim higher doses of radiation at your cancer while reducing the radiation to nearby healthy tissue. • Using medicines. Some drugs can help protect certain parts of
