Intraoperative Radiation Therapy (IORT)

Virginia Mason, in Seattle, Washington, is the first medical center in Washington state to offer intraoperative radiation therapy (IORT) to treat women with early stage breast cancer.

Radiation therapy helps prevent breast cancer recurrence by eliminating microscopic cancer cells following surgery. Standard radiation therapy requires daily treatment to the whole breast for three to six weeks. Even newer partial-breast irradiation techniques require 10 treatments over five days.

IORT is a much faster, more localized method of radiation treatment is available for patients following lumpectomy for breast cancer. IORT is a one-time treatment administered into the tumor bed at the time of breast surgery.

With IORT, a radiation oncologist and physicist work with the breast surgeon to deliver an effective dose of radiation in a single session. Immediately after removing the tumor, the radiation oncologist delivers a highly localized dose of radiation to the tumor site.

Benefits of IORT

IORT's benefits include:

  • A single radiation treatment at the time of operation: This lets patients complete surgery and radiation therapy at the same time, avoiding multiple trips to the hospital for standard radiation treatments.
  • Less risk to healthy tissues: During IORT, physicians move or shield healthy tissue to prevent damage from radiation, targeting cancer cells and leaving good tissue intact.
  • Recurrences can be treated again: Standard external-beam radiation can only be administered once, but if IORT patients experience a recurrence, they may be able to have another lumpectomy followed by radiation.

Who is eligible to have intraoperative radiation therapy?

Potential candidates for breast IORT are women aged 45 or older with a new diagnosis of early-stage breast cancer who are planning to undergo lumpectomy.

Since IORT is a new technique used to treat breast cancer, Virginia Mason only offers this treatment as part of a clinical study to patients who meet study eligibility criteria. We monitor patients over time to determine the treatment’s effectiveness.

For more information or to discuss if you may be a candidate for IORT, contact one of our Breast Cancer Nurse Coordinators at (206) 223-8862.