The colon is lined with epithelial cells, which can develop genetic mutations that cause them to grow abnormally quickly. When the cells develop the ability to invade surrounding tissues, they are called cancer cells. One way in which colon cancer can be treated is through the use of radiation therapy.
Mechanism
Radiation treatment works by sending high-energy X-ray beams into the cancer cells. These beams cause the DNA inside of the cancer cells to become damaged. This can either kill the cancer cells or slow down their growth while they attempt to repair the damage.
Radiation and Chemotherapy
According to the American Cancer Society, radiation treatments and chemotherapy are often given together. This is because both kinds of treatment work to poison or damage cancerous cells within the colon. Utilizing both treatments can have an additive effect, with the chemotherapy making the radiation more effective, and vice versa.
Indications
According to the National Cancer Institute, radiation therapy is often used to treat colon cancer that has begun to spread to other tissues. When colon cancer spreads, it is called metastasis. Radiation treatment is often used for these cases because it can be difficult to remove all the metastatic cancer tissue.
Types
There are three main kinds of radiation treatment for colon cancer. One is called external beam radiation therapy. With this type of therapy, the X-ray beams come from a device called a linear accelerator, located outside of the body. Endocavitary radiation therapy involves the insertion of a device into the rectum that delivers high doses of radiation therapy for a few minutes, after which it is removed. Brachytherapy is the third approach and involves the surgical implantation of small pellets of radioactive material. The pellets are put very near the cancer cells and deliver a steady dose of radiation that does not travel very far, which helps minimize the effects to the surrounding healthy tissue.
Side Effects
Although cancer cells are typically more sensitive to the effects of radiation than other kinds of cells, radiation treatments can cause certain side effects. Some patients experience nausea and fatigue as a result of the treatments. Patients may also develop irritation around the anus or have diarrhea as a result of inflammation of the colon. Radiation treatments can also lead to impotence.
