Radiation therapy is the kind of treatment that uses high energy X-rays or particles to destroy cancer cells. For some people with colon cancer treating them with chemotherapy and radiation therapy at the same time can work very well. The use of chemotherapy and radiation therapy together is known as chemoradiotherapy.
Radiation for colon cancer
Radiation therapy is not commonly used to treat colon cancer, but it is used in few cases like:
- Before surgery, along with chemotherapy it is used to shrink the tumor and make it easier to remove.
- During surgery, radiation is used in areas where the tumor was to kill the cancer cells that may be left behind. This process is known as intraoperative radiation therapy.
- After surgery, if the cancer has been attached to an organ or to the lining of stomach, radiation therapy may be used to kill the cancer cells that are left behind.
- Radiation is given along with chemotherapy to a person who is not healthy enough for surgery
- Radiation therapy is also used to ease symptoms of advanced cancer that can lead to intestinal blockage, bleeding or pain.
- Radiation therapy is used if the cancer has metastasized or spread to other areas such as the brain or lungs.
Types of Radiation
There are different types of radiation therapy that can be used to treat colon cancer.
External Beam Radiation Therapy (EBRT)
This is the most common kind of radiation that is used to treat colon or rectal cancers. In this type of radiation, the radiation is focused from outside the body through a machine. The amount of radiation given depends on different factors. Radiation is usually given over a course of few days.
Internal radiation therapy
This type of radiation is used for the treatment of some rectal cancers. For this kind of treatment, a radioactive source is put into the rectum next to or into the tumor. By doing this, the radiation is allowed to reach the rectum without passing through the skin and other tissues of the abdomen, so damage to other tissues is less likely to happen.
A procedure wherein radiation is given during embolization which is when substances are injected into the person’s blood vessels to try to block or reduce the blood flow to the cancer cells in the liver. This procedure allows doctors to treat metastatic tumors on the liver while minimizing the damage that is done to the healthy parts of the liver.