Intraoperative Radiation Therapy

Intraoperative Radiation Therapy

UW Medicine surgeons and Seattle Cancer Care Alliance (SCCA) radiation oncologists have years of experience with intraoperative radiation therapy (IORT). University of Washington Medical Center (UWMC) is the only hospital in the Pacific Northwest to offer this treatment.

A fast and effective form of radiation therapy, IORT is part of the advanced arsenal of treatments available to patients at SCCA. When tumors cannot be completely removed from the pelvic or abdominal regions because they are attached to important organs or nerves, or if cancer cells might have been left behind when a tumor was resected, surgeons can move normal structures out of the way during surgery to expose the area to high-dose electron-beam radiation.

How IORT Is Done

During surgery, a special radiation machine called the Mobetron is docked into position over a patient but never touches the patient. The machine is aligned to the patient with a special cone that focuses the treatment beam on the target so there is little effect from stray radiation on surrounding tissues and organs. Using a fraction of the total radiation given over a traditional multi-week course of external-beam treatment, IORT delivers precise bursts of radiation to the tumor.

Patients remain in the sterile surgical environment throughout the IORT procedure. The procedure adds about 60 minutes to the total length of surgery, but the treatment itself takes only a few minutes.

Tumors Treated with IORT

At UWMC, SCCA radiation oncologists use IORT to treat:

  • Locally advanced rectal cancers that are attached to normal structures, such as nerves, blood vessels, or the pelvic side wall, that cannot be removed
  • Abdominal and pelvic sarcomas that are attached to the back wall of the abdomen
  • Locally advanced gynecologic tumors, such as uterine or cervical cancers
  • Recurrent tumors
  • Select early stage breast cancers

IORT is a powerful tool that helps increase control rates for tumors that are difficult to remove completely with surgery. Used selectively and appropriately, along with neutron therapy, brachytherapy, and proton therapy, IORT is one of the many radiotherapeutic technologies available to cancer patients treated at UWMC and SCCA.