Radiation therapy, sometimes called radiotherapy, is a technique that uses high frequency X-rays to shrink or slow the growth of cancerous tumors. Unlike chemotherapy which is a systemic treatment, radiation therapy is a local treatment meant to destroy only tumor cells. During the treatment, a beam of radiation is directed through the abdomen to the cancerous area. The radiation is similar to that used for diagnostic X-rays, only in a higher dose.
Like chemotherapy, radiation therapy is sometimes used before surgery, after surgery, or both. When it is administered before surgery, the intent is to shrink the tumor enough to enable a surgeon to remove it. When it is given after an operation, the intent is to destroy any remaining cancer cells that may be present in the area. Radiation therapy is usually administered as an outpatient procedure at a hospital or clinic and is given 5 continuous days a week for 2 to 5 weeks.
Chemoradiation is a process in which radiation therapy is combined with chemotherapy.
The side effects of radiation therapy are typically isolated to the treatment area. Some common side effects associated with radiation therapy to the abdomen include nausea, vomiting, and diarrhea. These side effects may occur a few days or weeks after radiation treatments have started and continue for several weeks after completing the treatments. The side effects typically subside over time after the treatments are completed.