Colorectal Cancer Treatment
Radiation therapy is one of several types of treatment often used to treat cancers of the colon and rectum, collectively referred to as colorectal cancer. The radiation oncologist will consult with the surgeon and the medical oncologist who would administer chemotherapy, immunotherapy and/or targeted therapies to determine the right time for radiation treatments.
Surgery is typically required as part of colon or rectal cancer treatments. However, radiation therapy and/or chemotherapy are sometimes given before surgery to shrink the tumor for easier removal. For patients who may not be able to tolerate surgery, a chemo and radiation combination may be the best option for treatment.
Patients also receive radiation therapy after surgery. This might be necessary to be sure that all of the cancer cells have been killed that may have been left behind during surgery. Radiation therapy after surgery is also used to treat colorectal cancer cells that have attached to an internal organ or the lining of the abdomen.
You may not need radiation therapy before and after surgery. This will be up to your cancer care team to decide as they look at scans and test results.
External Beam Radiation Therapy for Colorectal Cancer
The most commonly used type of radiation therapy for colorectal cancer is external beam radiation therapy. This uses high-intensity beams of radiation, directed at a very specific area of the body, such as the colon or rectum, to kill cancer cells and shrink tumors.
With external beam radiation, the radiation comes from an x-ray machine called a linear accelerator. To begin the treatment process, you will go through a planning session called a CT simulation. The CT images are used to identify areas where treatment is needed and also areas that need to be protected. After the simulation session, daily treatments will begin.
During treatment, you will lie down so radiation can be applied to the pelvis from multiple directions. Each round of treatment is given five days a week for about 4 to 6 weeks. Progress on the shrinking of the tumor will be checked after each round of radiation therapy.
Possible Side Effects of External Beam Radiation for Colorectal Cancer
Before undergoing radiation therapy, talk with your radiation oncologist about what to expect, including the possible short- and long-term side effects. Side effects of radiation therapy will depend on factors such as the total dose of radiation and if chemotherapy is given at the same time (chemoradiation).
Possible side effects of radiation therapy for colorectal cancer can include:
- Skin irritation, such as redness, blistering, or peeling at the radiation site
- Rectal irritation, which can cause diarrhea, blood in the stool, or painful bowel movements
- Bowel incontinence (stool leakage)
- Urinary and bladder changes
- Sexual problems (erection issues in men and vaginal irritation in women)
Most side effects go away on their own, but some side effects may last a long time or become permanent. Talk to your oncologist or radiation technician right away if you notice any side effects so steps can be taken to reduce or relieve them.
Radiation Therapy in Georgia
Remember that you have a choice when it comes to where you receive your radiation therapy. With our cancer center located in the greater Atlanta area you won’t need to go into a hospital for treatment or deal with hospital parking for outpatient procedures. Find the location that’s closest to you.