Cancer is a disease where the body’s cells begin to grow out of control. Normal cells grow, divide, and die. Instead of dying, cancer cells continue to grow and form new abnormal cells. Cancer cells often travel to other body parts where they grow and replace normal tissue. This process, called metastasis, occurs as the cancer cells get into the bloodstream or lymph vessels.
Radiation therapy uses high-energy radiation to destroy or damage cancer cells, which grow and divide more quickly than normal cells and are more susceptible to being destroyed or damaged by radiation therapy. Radiation therapy is one of the most common treatments for cancer; it is used to treat more than half of all cancer cases. Radiation therapy is the only cancer treatment some patients receive. Unlike chemotherapy, which exposes the entire body to cancer-fighting chemicals, radiation therapy affects only the tumor and the surrounding area.
Types of Radiation Therapy
Radiation therapy can either be given externally or internally (called brachytherapy). Most patients receive external radiation therapy. Some patients may receive external radiation therapy and brachytherapy.
During external radiation therapy, an external machine directs high-energy rays at the cancer and some normal surrounding tissue. External radiation therapy is usually done on an outpatient basis five days a week for two to eight weeks.
Brachytherapy places radiation inside the body, as close as possible to the cancer cells. The radioactive material is sealed in a thin wire or a catheter (hollow tube) and implanted directly into the cancerous area. Brachytherapy concentrates the radiation on the cancer cells and lessens radiation damage to the normal tissue near the cancer. The implants can be temporary or permanent.
Another type of brachytherapy, radiopharmaceuticals, uses unsealed radioactive sources that are given orally or by injection.
Side Effects of Radiation Therapy
Most side effects of radiation therapy are related to the area that is being treated and go away within a few weeks after treatment ends. These side effects are not usually serious and can be controlled with medication or diet. Many patients have no side effects from radiation therapy.
Possible side effects are fatigue and skin changes near the treatment site (e.g., redness, irritation, or dryness). Brachytherapy can cause discomfort where the catheter is placed. If general anesthesia was used in brachytherapy, temporary drowsiness, weakness, or nausea can result.
The Radiation Therapy Team
During radiation therapy, a team of highly trained professionals work together to develop and implement a treatment plan that is customized to the patient and his/her cancer.
- A radiation oncologist, who heads the team, develops the treatment plan and oversees the treatment.
- The radiation physicist and dosimetrist ensure that equipment is functioning properly and calculate the correct dose of radiation.
- The radiation therapist administers the radiation treatments.
- The radiation oncology nurse provides education about radiation therapy.
For an appointment with an MD Anderson Cooper radiation therapy expert, please call 855.MDA.COOPER (855.632.2667).