190 women received radiation into open lumpectomy site during surgery experienced no local tumor recurrence after a mean interval of 51 months. This compared with a 6.4% local recurrence rate among 188 receiving external radiation therapy.

Sunnyvale, California; October 31, 2006 - Results of a long-term clinical study conducted in Salzburg, Austria, bolsters support for a promising change in radiation therapy for breast cancer patients. According to a report from Breast Center Salzburg published in the International Journal of Cancer, radiation administered during surgery, directly at the site of the excised tumor, greatly reduces the incidence of ipsilateral (same side) breast tumor recurrence. The findings were delivered by Dr. Felix Sedlmayer, chairman of radiation oncology at the University of Salzburg, on Oct. 8 at a special meeting of the European Chapter of the International Society of IORT held at the ESTRO25 (European Society for Therapeutic Radiation and Oncology) conference in Leipzig, Germany.

The study compared 190 women who received IOERT during lumpectomy followed by whole-breast radiation, with the 188 previously treated women who received lumpectomy alone, followed by whole-breast radiation using an externally applied electron beam boost to the tumor bed. After a median follow-up period of 51 months, no local tumor recurrence occurred in the IOERT group; after a median follow-up period of 81 months, 6.4% of the other group had experienced local breast cancer recurrences.

Because it does not have to pass through healthy skin, organs and tissue, IOERT can be delivered at higher and better cancer-killing doses. It may also permit the post-operative radiation cycle to be shortened by as much as half, depending on the protocol. Guided by the radiation oncologist’s clear view of the site as well as intraoperative ultrasound, IOERT also allows the electron beam to be more accurately targeted. In addition, IOERT eliminates the traditional delay of external radiation therapy, which must be scheduled only after the surgery patient has healed. This can give cancer cells a chance to recover and spread.

A reduction or even a long delay in local tumor regrowth strongly predicts better long-term survival rates, according to the report. Previous studies have shown that patients who develop local recurrences within two years fare much worse than those who develop such recurrences after more than five years.

A subsequent study conducted by Dr. Sedlmayer involved 541 breast cancer patients that were advised to have breast conserving therapy. As of March 2004, 541 patients received IOERT during surgery. Ranging in ages from 23 to 89, with a median age of 50.4 years, only one patient had an in-breast recurrence after 36 months. This recurrence was due to a previously unidentified tumor and not at the original tumor site. Dr. Sedlmayer was able to achieve 100% local tumor control and an overall survival rate of 92.1 % for his patients after five years.

While IOERT has been in use for years, mainly in Europe, cost has been an obstacle to more widespread adoption. Constructing and equipping an operating room with the necessary radiation shielding and facilities can run into the millions. Alternatively, some hospitals wheel patients under surgery to their radiology departments for IOERT, incurring additional risks of infection. Many areas in the U.S. are not within practical distance of IORT treatment at all.

Nearly all Austrian women live within a two-hour drive to radiation facilities, notes Dr. Felix Sedlmayer. But American hospitals are not as well equipped, or are strapped by the coverage constraints of private health insurance companies. "Obviously, many women in the U.S. are simply forced to choose mastectomy for lack of nearby equipped radiation facilities, or lack of healthcare coverage for IORT," says Dr. Sedlmayer. "This takes an unacceptable psychological and physical toll. Given the lowered recurrence rates we are seeing, the estimated 216,000 new cases of invasive breast cancer per year in the U.S. and an estimated breast-conserving surgery rate of 70 percent, the U.S. alone could avoid 5,000 cases of local recurrence per year."

Help is on the way, in a device that not only makes the treatment portable, but affordable for many more hospitals. The first fully mobile, self-shielding intraoperative radiation therapy system has been developed by IntraOp Medical. The Mobetron, it delivers the same electron-based radiation therapy administered in dedicated, shielded operating rooms, without needing to move the patient or make structural changes to surgery suites. "As a self-shielding, mobile device, the Mobetron represents a technology investment that comes in much lower and can be leveraged across many operating suites," says Donald A. Goer, president and CEO of IntraOp Medical Corp. "Hospitals have been caught between the needs of the cancer patient and the overwhelming costs of breakthrough medical equipment. Now, they can harness its power and efficacy in many more surgeries than they could in a dedicated, radiation-shielded or costing twice as much. Virtually any cancer surgery patient can benefit from IORT."

To date, Mobetrons have been deployed in university research centers and specialized cancer clinics in North America, Europe and Asia. The latest facility to install the device is St. Augustinus Hospital in Antwerp, Belgium. A 600-bed hospital that treats about 2,500 cancer patients per year, it took delivery in September 2006.

About Intraop

IntraOp Medical Corporation provides innovative technology solutions for the treatment and eradication of cancer. Founded in 1993, IntraOp is committed to providing the tools doctors need to administer intraoperative radiation therapy safely and effectively - for all cancer patients. The company's flagship product, Mobetron, is the first fully portable, self-shielding intraoperative electron radiation therapy device designed for use in any operating room. Key Mobetron benefits include: increased survival rates, better local tumor control, shorter treatment cycles, and fewer side effects. Leading hospitals, from university research centers to specialized cancer clinics in North America, Europe and Asia, use Mobetron as a vital part of their comprehensive cancer program.

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