Radiation therapy is one of several types of treatment that can be used to treat colorectal cancer (cancer of the colon or rectum). It may be given before surgery, after surgery, or both depending on whether the cancer spread and what was found during surgery.
Your treatment plan is based on the stage of the cancer and location in the body. Because of this, our radiation oncologists, Dr. Ankit Agarwal and Dr. John Shumway, will consult with the rest of your cancer care team to determine the right type and amount of radiation therapy that may be needed.
External Beam Radiation Therapy for Colorectal Cancer
External beam radiation therapy is the most common type of radiation therapy used for colorectal cancer. This uses high-intensity beams of radiation, directed at a very specific area of the body, such as the colon or rectum, to shrink tumors and kill cancer cells. Learn more about IMRT and IGRT, the two types of external beam radiation therapy available at Silicon Valley Oncology for colorectal cancer patients.
With external beam radiation, the radiation is delivered by a machine called a linear accelerator. To begin the treatment process, you will go through a planning session called a simulation. CT images are taken and then 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 each treatment, you will lie down in the exact same spot on the linear accelerator so radiation can be applied to the pelvis from multiple directions. At Silicon Valley Oncology, patients receive external radiation therapy during short outpatient visits over several weeks. Progress of the shrinking of the tumor will be checked frequently.
Possible Side Effects of External Beam Radiation for Colorectal Cancer
Before undergoing radiation therapy, the care team who works with Dr. Agarwal and Dr. Shumway will talk with you about what to expect, including the possible short- and long-term side effects you could experience, as well as symptom management. Side effects will depend on the amount of radiation delivered, individual responses, the site that's being treated, and whether 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
Fatigue
Rectal irritation, which can cause diarrhea, blood in the stool, or painful bowel movements
Diarrhea
Urinary and bladder changes
Fertility problems
Sexual problems (erection issues in men and vaginal irritation in women)
In most cases, side effects go away on their own, however, some may last a long time or become permanent. Talk to your medical oncologist or radiation technician right away if you notice any side effects so steps can be taken to reduce or relieve them.
Radiation Therapy Made Convenient in Campbell, California
Remember, you have a choice when it comes to where you receive your radiation therapy. With our office located in Silicon Valley we’re conveniently located near San Jose, Santa Clara, Alamitos, Los Gatos and Cupertino. Avoid hospitals and the parking headache that goes with them! Contact us to schedule a radiation therapy consultation.