Mobetron portable radiation therapy system for breast cancer treatment

Sep 16 2009

One minute of radiation in the operating room (OR) could save the lives of thousands of women being treated for breast cancer in the US today. According to a growing body of research, a 60-second course of radiation therapy delivered during surgery dramatically improves results. But, until recently, logistical and administrative difficulties prevented most patients from receiving this crucial treatment until weeks after their procedures.

Now, a portable, self-contained radiation therapy system, the Mobetron from IntraOp Medical Corporation (OTCBB: IOPM; Sunnyvale, Calif.), is changing all that. St. Joseph Hospital (Orange, Calif.), one of only 16 prestigious designated National Cancer Institute Community Cancer Centers, this month introduced the first ongoing intraoperative electron radiation therapy (IOERT) program for breast cancer. During lumpectomy surgery, St. Joseph’s patients receive a high dose of therapy focused specifically on the tumor site, known as a “boost.” Given the benefits, other facilities are expected to follow suit.

Felix Sedlmayer, MD, one of the world’s leading IOERT researchers and the principal investigator of IOERT boost trials conducted by six European medical centers over the past decade, concluded that IOERT cut breast cancer five year recurrence rates dramatically, from an average of 5% to less than 1%.

“If the IOERT boost were a standard technique in the US, every year, more than 5000 breast cancer recurrences could have be avoided,” according to Roland Reitsamer, MD, a surgeon at the University of Salzburg, where the technique has been studied extensively for the past decade. Each one of those recurrences typically would result in a subsequent mastectomy, which also would be avoided. A prestigious Lancet review of studies on breast cancer found a 25% increase in 15 year survival for patients with no recurrences at five years, suggesting that IOERT boost could have a significant impact on the survival of thousands of women worldwide.

What every woman should know about intraoperative radiation

It seems a matter of common sense. Lumpectomy is typically followed by a six-week course of radiation therapy to help eliminate any remaining malignant cells. Treatment takes place at least four weeks after surgery when the breast has healed. Because traditional, post-operative radiation is delivered externally, it must pass through the body to reach diseased areas, and healthy tissue may be damaged in the process. Additionally, once surgery is complete, physicians no longer have direct access to the target area to easily and precisely deliver radiation.

So why not begin the radiation treatment during the surgery itself? This would immediately target any remaining cancer cells, while allowing complete access to the tumor area for greater precision in radiation delivery. It also would spare radiation dose to surrounding tissue and reduce the number of days a woman has to travel to a cancer center for external treatment after surgery. In fact, at St. Joseph, IOERT will shorten the course of post-operative radiation by seven to 10 days by delivering the targeted boost dose prior to, rather than after, traditional treatments.

“The answer is that intraoperative radiation simply hasn’t been practical until now,” explains John Powers, CEO for IntraOp. ”Without the Mobetron, the treatment would mean equipping a special operating room with a costly, unwieldy 18,000 pound linear accelerator to generate radiation as well as a shielded radiation vault to protect staff from repeated exposure to this radiation. This is just not feasible for most hospitals.”

The other alternative, Mr. Powers points out, has been transferring patients under anesthesia with an open incision from the OR to a radiation therapy center, typically located offsite. This significantly increases the risk and duration of surgery and anesthesia. The result: despite its enormous benefits, IOERT has rarely been used in the US for breast patients.

However, IOERT has been heavily investigated in major European university hospitals and is currently in use in more than a dozen facilities. This is not surprising because historically the European medical system has been an early adopter of promising new paradigms for breast cancer diagnosis and treatment, including mammography, breast conserving lumpectomy and sentinel node biopsy.

The Mobetron

Specifically optimized for IOERT, the IntraOp Mobetron incorporates a range of technological innovations to make all the benefits of this treatment realistic and practical for women and their doctors around the world. The innovative system eliminates the risk, time, cost and complexity of IOERT by enabling delivery in any standard OR.

Unlike conventional linear accelerators, the Mobetron is relatively lightweight and can be wheeled among different OR locations. The Mobetron requires no external radiation vault or bunker because patented technologies eliminate most stray room radiation generated by conventional accelerators and because of its patented self-shielding,

To operate the device, following tumor excision, a Mobetron applicator tube is temporarily inserted into the breast to provide precise treatment directly to the tumor bed. The Mobetron is positioned for radiation delivery, and the one-minute treatment takes place.