Breast Cancer: Intraoperative Radiotherapy – The 5 year Lesson

Breast tangential fields breath hold

Early breast cancer may be treated with a number of radiation tools: 1) External beam radiation therapy (has the longest track record); 2) Partial breast radiation therapy  (many techniques offering the potential of less toxicity and shorter courses of treatment). One of the most innovative partial breast irradiation (PBI) approaches is known as Intraoperative Radiation Therapy (IORT). One such approach(available only for highly selected patients with node-negative, early breast cancer that is not high grade) that has long-term follow-up uses whole breast radiation therapy, but for only 16 treatments. Imagine if we could give the radiation therapy in one shot, while you are asleep in the operating room.

IORT: Intraoperative radiation therapy is a technique that delivers your radiation treatment while you are still in surgery. The radiation beam is aimed directly at the exposed tumor bed, while surrounding healthy tissue is moved aside. This technology is being used in Asia and in Europe. Here in the USA, it is in clinical trials (experiments). You may be a candidate for IORT if you cancer is low-grade, early stage , has no lymph node involvement, and  clear surgical margins. And access: Most centers do not have IORT. Potential complications include fat necrosis, blood collections (hematoma), and scarring.

Hot off the press: 5 year results from the Electron Intra Operative Radiation Therapy (ELIOT) trial, presented in April 2013 at the 2nd EuropeanSociety for Radiotherapy & Oncology (ESTRO) Forum. The ELIOT trial is a single institution trial that ran from 11/2000 to 12/2007. Patients with breast cancer were ages 48 or older,and small tumors (no larger than 2.5 cm or 1 inch). Patients were randomized to receive IORT (21 Gy dose) to the tumor bed, or conventional radiation therapy.

Results: The local recurrence rates were much better with conventional radiation therapy (5.3% versus 0.7%) at the 5 year mark. There were no differences in survival chances, though. Fat tissue necrosis occurred in 12% of the ELIOT group. There were no differences in pain or skin changes (except for less scarring in the IORT group). Mild lung scarring (by imaging) was more common in the conventional radiation group.

My take: There are certainly potential upsides to IORT: 1) Only 1 radiation treatment, so more convenient for the patient; 2) Potentially fewer side effects; 3) potentially better cosmetic outcomes; 4) faster recovery; 5) potential cost-savings. However, there are potential downsides: 1) Small risk of infection; 2) few patients have access to the technology; 3) workflow during surgery must be highly coordinated between the surgeon and the radiation oncologist; 4) it is not appropriate for many patients with breast cancer. But the biggest disadvantage in my view: NO LONG-TERM follow-up. A survival disadvantage may yet emerge. The results from Milan (Italy) appear more encouraging. I think that is because the Italians assess the margins carefully, and add whole breast conventional radiation therapy (after the IORT) if the margins are not acceptable. The ELIOT trials show us the perils of IORT; the Italian (early) results suggest the promise for highly selected patients with clear margins.

The small print: The material presented herein is informational only, and is not designed to provide specific guidance for an individual. Please check with a valued health care provider with any questions or concerns. As for me, I am a Harvard- , Yale- and UPenn-educated radiation oncologist, and I practice in the Seattle, WA (USA) area. I feel genuinely privileged to be able to share with you. If you enjoyed today’s offering, please consider clicking the follow button at the bottom of this page.

Coming Soon for iPad:  Understand Breast Cancer in 60 Minutes; Understand Colon Cancer in 60 Minutes. Available now: Understand Colon Cancer in 60 Minutes; Understand Brain Glioma in 60 Minutes. All can be found at the Apple Ibooks store. Thank you.

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