Intraoperative radiation therapy for breast cancer

Princess Margaret Hospital (PMH) breast cancer specialists are using a new way to treat patients by delivering a one-time dose of radiation during surgery.

The procedure, called intraoperative radiation therapy, takes less than an hour and eliminates the need for further radiation treatments.

On May 17, the PMH team combined the expertise of surgeons, radiation medicine specialists (radiation oncologists, physicists and therapists) and nurses to perform its first procedure. It marked the first time the portable intrabeam radiotherapy machine that makes this procedure possible has been used in Canada. The PMH team has since treated two more patients.

"The potential benefits to patients are huge," says lead surgeon Dr. David McCready, who also heads the PMH Breast Cancer Program. "Treating the specific area of cancer with this kind of precision protects the skin, heart and lungs from unnecessary radiation, minimizes side effects, and saves the patient a lot of time."

Here's how it works: Using a probe attached to the portable intrabeam radiotherapy machine, a single, concentrated dose is inserted directly into the affected area inside the breast during surgery. Dr. McCready says the one-time dose is ,biologically equivalent, to conventional radiation treatments for breast cancer that typically require, on average, a minimum of 16 treatments over three weeks.

Dr. Anthony Fyles, the radiation oncologist who leads the Breast Radiation Oncology Program and treated the first patient in the operating room that day, says: "This procedure is helping us understand more about the biology of how breast tissue responds to treatment. That knowledge, in turn, will help us further customize and select the best treatment options for individuals with early breast cancer."

Next, Drs. McCready and Fyles will join a randomized clinical trial to further study the results of using this procedure. The study participants from PMH will generally be older patients with small, early-stage tumours (less than 2 cm). The revolutionary technique was pioneered four years ago in Britain, where more than 800 women are now part of an international trial.