Radiation Therapy for Colorectal Cancer
by Jondavid Pollock, MD, PhD
Radiation therapy uses high energy x-rays to kill cancer cells. Radiation is tailored for each person. This helps to deliver as much radiatoin as possible to cancer cells and decrease harm to healthy cells. Radiation therapy is often used along with other treatments, such as surgery and chemotherapy. It may be used to clear any cancer cells left after surgery. Some may need it if they cannot have surgery, but this is rare.
Types of radiation therapy used for colorectal cancer are:
External Beam Radiation
Short bursts of x-rays are fired from a machine toward the cancer. Special blocks are used to shape the radiation beam. Marks are also made on the body. These steps help to focus the beam. It will help to treat the cancer and harm as little normal tissue as possible.
Side Effects and Management
Radiation to the belly and pelvis may cause:
Other treatments can help to ease side effects. It can help treat dry, irritated skin, nausea, vomiting, or diarrhea. Radiation treatment can also affect some blood cells. This can lead to anemia and fatigue. Medicine can help to improve blood cells. Early treatment of side effects may have best outcome.
Benson AP, Venook AB, Cederquist L, et al. Colon Cancer. Version 2.2017. In: National Comprehensive Cancer Network (NCCN) Clinical Practice Guidelines in Oncology (NCCN Guidelines). NCCN 2017 Mar from NCCN website.
Colon cancer treatment option overview. National Cancer Institute website. Available at: https://www.cancer.gov/types/colorectal/patient/colon-treatment-pdq#section/_135. Updated January 30, 2020. Accessed February 27, 2020.
Colorectal cancer. American Cancer Society website. Available at:
...(Click grey area to select URL)
Accessed February 27, 2020.
Colorectal cancer. EBSCO DynaMed website. Available at: https://www.dynamed.com/condition/colorectal-cancer. Updated January 22, 2020. Accessed February 27, 2020.
Glynne-Jones R, Wyrwicz L, Tiret E, et al. Rectal cancer: ESMO Clinical Practice Guidelines for diagnosis, treatment and follow-up. Ann Oncol. 2017 Jul 1;28.
Last reviewed December 2019 by Mohei Abouzied, MD
Last Updated: 2/27/2020
EBSCO Information Services is fully accredited by URAC. URAC is an independent, nonprofit health care accrediting organization dedicated to promoting health care quality through accreditation, certification and commendation.
This content is reviewed regularly and is updated when new and relevant evidence is made available. This information is neither intended nor implied to be a substitute for professional medical advice. Always seek the advice of your physician or other qualified health provider prior to starting any new treatment or with questions regarding a medical condition.
To send comments or feedback to our Editorial Team regarding the content please email us at email@example.com. Our Health Library Support team will respond to your email request within 2 business days.