Skip to main content

ACS & ASCO are Stronger Together: Cancer.Net content is now available on



Radiation Therapy for Gastrointestinal Stromal Tumors

Radiation therapy is the use of high-energy x-rays (or particles) to kill cancer cells. Radiation is not very helpful in treating gastrointestinal stromal tumors (GISTs), so it is not used often. But sometimes it can be used to relieve symptoms like bone pain.

Before your treatment starts, the radiation team will take careful measurements to find the correct angles for aiming the radiation beams and the proper dose of radiation. This planning session, called simulation, usually includes getting imaging tests such as CT or MRI scans.

Radiation therapy is much like getting an x-ray, but the radiation is much stronger. The treatment itself is painless. It lasts only a few minutes, although the setup time – getting you into place for treatment – usually takes longer. You might get radiation treatment for several days in a row.

Possible side effects of radiation

Depending on where the radiation is aimed, side effects may include:

  • Skin changes in areas getting radiation, ranging from redness to blistering and peeling
  • Nausea and vomiting
  • Diarrhea
  • Fatigue
  • Low blood counts

Most side effects go away a short while after treatment ends, although fatigue and skin changes may last longer. Talk with your doctor about the possible side effects and the ways to reduce or relieve them.

More information about radiation therapy

To learn more about how radiation is used to treat cancer, see Radiation Therapy.

To learn about some of the side effects listed here and how to manage them, see Managing Cancer-related Side Effects.

The American Cancer Society medical and editorial content team

Our team is made up of doctors and oncology certified nurses with deep knowledge of cancer care as well as editors and translators with extensive experience in medical writing.

Casali PG, Dei Tos AP, Gronchi A. Chapter 60: Gastrointestinal Stromal Tumor. In: DeVita VT, Lawrence TS, Rosenberg SA, eds. DeVita, Hellman, and Rosenberg’s Cancer: Principles and Practice of Oncology. 11th ed. Philadelphia, Pa: Lippincott Williams & Wilkins; 2019.

Morgan J. Tyrosine kinase inhibitor therapy for advanced gastrointestinal stromal tumors. UpToDate. 2019. Accessed at on October 21, 2019.

National Cancer Institute. Physician Data Query (PDQ). Gastrointestinal Stromal Tumors Treatment. 2018. Accessed at on October 21, 2019.

National Comprehensive Cancer Network (NCCN). NCCN Clinical Practice Guidelines in Oncology: Soft Tissue Sarcoma. V.4.2019. Accessed at on October 21, 2019.

Last Revised: December 1, 2019

American Cancer Society Emails

Sign up to stay up-to-date with news, valuable information, and ways to get involved with the American Cancer Society.