We teach you about intraoperative radiation therapy (IORT) for early stage breast cancer. This one-time dose of accelerated partial breast radiation is an option in some with early stage breast cancer.


Questions for your Breast Surgeon and Radiation Oncologist:

  • Am I a candidate for IORT?
  • Would you recommend I consider IORT?
  • What are the advantages of IORT compared to standard radiation?
  • What are the disadvantages of IORT?

What is intraoperative radiation therapy (IORT)?

Intraoperative Radiation Therapy is an evolving technique of radiation therapy for women having a lumpectomy for favorable, early stage breast cancer. “Whole Breast Radiation” is still considered the standard of care. IORT is slowly becoming more available at hospitals across the country. It is appropriate for only a small proportion of patients with small breast cancers. Also known as a type of Accelerated Partial Breast Irradiation (APBI), IORT is a technique of delivering a one-time dose of radiation to the lumpectomy area during surgery versus whole breast radiation – a treatment that takes usually four to six weeks. IORT is still an investigational therapy and not yet incorporated into national breast cancer guidelines.


When a lumpectomy is performed for breast cancer, radiation is usually recommended to reduce the chance of cancer re-growing in the lumpectomy area of the breast. IORT applies a single dose of radiation to the operative lumpectomy site while under anesthesia in the operating room. Only women who meet the strict criteria for IORT should consider this mode of radiation. Learn more with our video lesson Will I Need Radiation?



*Courtesy of Carl Zeiss Meditec, Inc.

What are the general criteria to have IORT?

This therapy may be an option for women older than 45, a “favorable” tumor smaller than 2.5 cm, and no evidence of cancer in the lymph nodes. There are other, specific criteria that can exclude eligibility. The decision to consider IORT must be made with your breast surgeon and radiation oncologist before surgery. It takes a great deal of coordination with your surgeon, radiation oncologist, and hospital to be prepared to perform IORT during your lumpectomy surgery. Most hospital facilities currently do not offer this form of breast cancer radiation.


What are the Advantages of IORT?

The most attractive aspect of IORT is completing a surgical lumpectomy, sentinel node biopsy, and radiation therapy in one day. If successful, you can avoid the 4 to 6 weeks of daily trips to your radiation center to receive whole breast radiation.


Another advantage is that IORT applies the radiation to only the site of the surgery, where cancer cells could be unknowingly left behind and grow again in the future. Whole breast radiation is applied to the entire breast and could affect other healthy tissue. As a result, IORT can focus radiation just on the area of the lumpectomy site. Review our lesson on Brachytherapyto learn more about shorter course radiation options.


What are the disadvantages of IORT?

IORT is a new technology, so the long-term success rate for keeping cancer from returning in the breast is still uncertain with this technique. As a result, whole breast radiation is still considered the standard of care to reduce “local recurrence” of cancer in the breast after a lumpectomy. The “Targit-A” and “ELIOT” clinical trials did show statistically higher recurrence rates at 5 years for IORT when compared to whole breast radiation in highly selected patients. The NCCN (see below link) has yet to add IORT to their treatment guidelines. Other studies are in progress to study IORT’s effectiveness. We currently are awaiting studies to see if IORT is effective at 10 years which is the benchmark for success in the field of radiation therapy.

Patient-Friendly References:

An excellent detailed overview of IORT is located (here). This site is created for patients by the American Society of Breast Surgeons.


This page (here) has a general outline of breast radiation. It mentions IORT briefly as an option. The American Cancer Society is an organization that supports patients with cancer and funds research for cancer of all types.


Videos about IORT:

This Zeiss Medical Technologies YouTube Video animation (here) describes intraoperative radiation using their Intrabeam IORT system. Carl Zeiss Meditech is a leading medical device company.


Xoft Incorporated has several videos (here) on their website that describe the operative procedure using their “eBx” IORT system. Xoft Inc. is a medical device company that specializes in therapeutic radiation.


More Detailed References:

If you want to get deep into the details, this free 200-page pdf document by the National Comprehensive Cancer Network has guidelines to help clinicians make treatment recommendations about nearly all aspects of breast cancer. You can easily register (here) as a non-professional to get access. IORT is currently not incorporated into the NCCN Guidelines.




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