Getting Intraoperative Radiation Therapy (IORT)
Intraoperative radiation therapy (IORT) is radiation treatment given directly to a tumor during surgery. This type of treatment delivers one large dose of radiation to the cancer and limits the damage to nearby tissue.
Some people may get IORT in addition to external beam radiation and chemotherapy.
What types of cancers are treated with IORT?
IORT may be used for tumors that can’t be removed completely or when there’s a high risk that the cancer will come back in the same area. The goal is to decrease the chance of the cancer coming back.
IORT may be used to treat these types of cancer:
- Breast cancer
- Soft tissue sarcomas
- Pancreatic cancer
- Rectal cancer
More research is needed to see if IORT can be helpful in treating other types of cancers.
Who is a candidate for IORT?
Whether or not a person is a candidate for IORT depends on many factors, including:
- The type of cancer
- Location and size of the tumor
- A person’s overall health
If your cancer care team thinks you might be a candidate, you will meet with a surgeon and a radiation doctor. If you are a candidate, your care team will talk with you about this treatment option so you can decide if it’s right for you.
What happens during IORT?
IORT is given during surgery in a special operating room. You will be under general anesthesia (in a deep sleep).
First, the tumor is removed. Next, radiation is given to the area of the tumor using a machine called a linear accelerator (LINAC). Other healthy tissues in your body are protected with special shields.
After radiation, the surgeon closes the incision.
What are the risks (side effects) of IORT?
Side effects of IORT may include:
- Problems with the surgical site healing
- Tissue damage and scarring (fibrosis)
- Nerve damage
- Infection
- Irritation or redness of the skin (radiation dermatitis)
- Collection of fluid under the skin (seroma)
- Collection of blood under the skin (hematoma)
Ask your cancer care team what side effects you might have and how to manage them.
What are the benefits of IORT?
Benefits of IORT include:
- Higher doses of radiation given directly to the location of the tumor
- Limits the damage to healthy tissues around the tumor
- May reduce the number of treatments you need
What are the limitations of IORT?
Limitations of IORT may include:
- More research is needed to determine who will benefit from IORT.
- IORT needs expensive machines and skilled cancer care teams, so it may not be given at all cancer treatment centers.
- Treatment can be expensive. Not all insurance companies may cover IORT.
- IORT may increase surgery time.
- Your pathology report isn’t back from the lab before radiation treatment happens. This report includes detailed information about your tumor, which helps your care team decide your treatment plan.
To learn more about other types of radiation therapy used to treat cancer, see Radiation Therapy.
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- References
Developed by the American Cancer Society medical and editorial content team with medical review and contribution by the American Society of Clinical Oncology (ASCO).
American Society of Clinical Oncology (ASCO). What is radiation therapy? Accessed at cancer.net. Content is no longer available.
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Last Revised: June 9, 2025
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