Image-guided radiation therapy, also called IGRT, is a type of radiation therapy. Radiation therapy uses powerful energy beams to kill cancer. The energy can come from X-rays, protons or other sources. In IGRT, images are used to help plan the treatment.

When undergoing IGRT, high-quality images are taken before each radiation therapy treatment session. The images are used to increase the accuracy and precision of the radiation treatment.

IGRT may make it possible to use higher doses of radiation. This may increase the effectiveness of the treatment and may result in shorter treatment schedules. The radiation may reach less of the healthy tissue around the target.

IGRT is the standard of care for radiation therapy treatment. It's used to treat all types of cancer. It's also sometimes used to control tumors that aren't cancerous.

Why it's done

IGRT is used to treat all types of cancer, but it's particularly ideal for tumors and cancers located very close to sensitive structures and organs. IGRT is also useful for cancers that are likely to move during treatment or between treatments.

What you can expect

If you undergo IGRT, your treatment team may choose one or more imaging types to precisely locate the cancer and sensitive organs. IGRT may involve a variety of 2D, 3D and 4D imaging techniques to position your body and aim the radiation so that your treatment is carefully focused on the cancer. This helps to minimize harm to healthy cells and organs nearby.

During IGRT, imaging tests are done before, and sometimes during, each treatment session. Your radiation therapy team compares these images to ones taken previously to determine if your cancer has moved and adjust your body and your treatment to target the cancer more precisely.

Image-guided radiation therapy (IGRT) care at Mayo Clinic

April 05, 2023
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  2. Image-guided radiation therapy (IGRT). RadiologyInfo.org. https://www.radiologyinfo.org/en/info/igrt. Accessed Jan. 16, 2023.
  3. Accredited facility search. American College of Radiology. https://www.acraccreditation.org/accredited-facility-search. Accessed Jan. 16, 2023.
  4. Nguyen H. Allscripts EPSi. Mayo Clinic. May 5, 2022.


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