Intraoperative Radiation Therapy (IORT)

During intraoperative radiation therapy (IORT), a surgeon removes a cancerous tumor. Then, a radiation oncologist treats the surrounding tissue with radiation. You receive radiation immediately after surgery while you’re still in the operating room. IORT offers the same benefits as other types of radiation therapy in just one treatment session.


What is intraoperative radiation therapy (IORT)?

Intraoperative radiation therapy (IORT) is a cancer treatment that delivers radiation during surgery. Your surgeon first removes the cancerous tumor. Then, your radiation oncologist delivers targeted radiation to the area where the tumor was removed. This helps increase the chances that the tumor won’t come back. IORT may be used to treat several types of cancer, but it’s most commonly used for breast cancer.

What conditions are treated with IORT?

Healthcare providers can use intraoperative radiation therapy for:

Who is a candidate for intraoperative radiation therapy?

It depends on a variety of factors including what type of cancer you have, tumor size, and your overall health. Your surgeon and radiation oncologist will work together to determine if IORT is right for your specific case.


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Procedure Details

What happens during intraoperative radiation therapy?

On the day of your treatment, you receive general anesthesia so you remain asleep during the procedure. During intraoperative radiation therapy (IORT):

  1. Your surgeon removes the tumor.
  2. Your surgical oncologist places an applicator into the area where the tumor was removed.
  3. Your radiation oncologist prescribes a specific amount of radiation, which travels through the applicator to target and treat the surrounding tissues.
  4. Your surgical oncologist removes the applicator.
  5. Your surgeon then closes the incision.

Risks / Benefits

What are the benefits of IORT?

Traditionally, people who have cancer receive radiation therapy daily over several weeks. But with IORT, you get the required amount of radiation in a single session, allowing you to complete the entire course of radiation treatment in one appointment.

IORT offers multiple benefits, including:

  • Fewer treatment sessions.
  • Less damage to surrounding tissues.
  • Lower risk of side effects.


Recovery and Outlook

How effective is intraoperative radiation therapy?

Several studies have shown that survival rates are similar, with fewer complications than traditional radiation therapy. Your oncologist will discuss the chances of tumor local recurrence, along with the risks and benefits of IORT, with you before treatment.

When To Call the Doctor

When should I call my healthcare provider?

Call your healthcare provider if you experience any severe or unexpected side effects after IORT, like:

  • Bleeding.
  • Discharge at the incision site.
  • Fever or chills.


Additional Common Questions


In external beam radiation therapy (EBRT), a machine outside of your body directs radiation beams toward you. EBRT delivers radiation to the tumor and some of the surrounding tissue. Healthcare providers use lower daily doses of radiation during EBRT to minimize the risks to healthy tissue.

In intraoperative radiation therapy (IORT), a surgical oncologist places a radiation applicator inside your body. The radiation applicator then delivers radiation directly to the tissue surrounding the tumor cavity. Providers can use a higher dose of radiation during IORT because they’re able to target the tumor area only.

A note from Cleveland Clinic

While lifesaving, cancer treatment can be exhausting. Daily trips to the hospital for radiation therapy and uncomfortable side effects can add stress to a time in your life that’s already overwhelming. For select people, intraoperative radiation therapy (IORT) may be an effective solution.

But IORT isn’t for everyone. Your cancer care team will help you determine the best course of treatment so you have the best possible outcome with the least amount of side effects. Whether or not you receive IORT, talk with your care team about what you’re going through, including fatigue, stress and treatment side effects. They’ll help you find the support you need.

Medically Reviewed

Last reviewed on 01/22/2024.

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