Radiation therapy uses high-energy X-rays to destroy cancer cells. Radiation therapy is considered a local treatment, as it only affects one part of the body. The goals of radiation therapy include shrinking the tumor before surgery, keeping the tumor from returning after surgery, eliminating cancer cells in other parts of the body, and relieving pain (palliation).
Radiation therapy can be given two ways: externally and internally. With external-beam radiation therapy, a machine directs the radiation at the tumor from outside the body. With internal radiation therapy, also called brachytherapy, small tubes or implants (also called seeds) containing radioactive materials are placed in the body near the tumor. With internal radiation therapy, the person does not need to come to the hospital every day to be treated, and the doctor can use a higher dose of radiation. However, internal radiation therapy can only be used if the tumor is in a location where the doctor can place the implant.
Before beginning external-beam radiation therapy, the doctor will plan where to aim the radiation. The goal is to hit as much of the tumor as possible while minimizing the exposure of healthy tissue. A person’s skin may be marked to show where the radiation will be directed. New computerized techniques help pinpoint the best place to give the radiation.
Side effects of radiation treatment
Like chemotherapy, radiation therapy can also damage normal cells, causing side effects. These include tiredness (fatigue), swelling, redness or irritation of the skin, hair loss, cough or shortness of breath (if the radiation is given to the neck or chest area), mouth sores (if the radiation is given to the head), and digestive problems (if the radiation is given to the abdominal area). These side effects go away once treatment is finished. Internal radiation therapy may cause bleeding, infection, or irritation after the implant is removed. Radiation treatment does not make a person radioactive. Read more about Managing Side Effects.
External-beam radiation therapy may have long-term side effects that can affect a person for many years. For this reason, children and young adults who receive radiation therapy should keep a record of their radiation treatment schedule (including the dose and location of the radiation) and report it as part of their medical history. Long-term side effects can include the risk of a second cancer, the inability to have children (infertility), heart problems (from radiation to the chest), gastrointestinal problems (from radiation to the abdominal area), lung fibrosis (scarring or thickening of the lung tissue), neurological problems, thyroid problems, or osteoporosis. Also, people who have had previous radiation to the chest should be aware that they are at higher risk of developing breast and lung cancers. Today, most people who receive radiation therapy now receive smaller doses than what was given in years past. Each individual considering radiation therapy should discuss the risks versus benefits of the treatment with his or her doctor.