Brain-cancer-patient alert

A radiation-therapy device error may affect people in France, U.S. Risk was downplayed.

Hundreds of brain-cancer patients in France and perhaps others in the United States may be contacted about their radiation treatments from malfunctioning machines, which were ordered shut down by the French government this week after a manufacturer's warning.

The maker of the equipment, Brainlab of Munich, Germany, downplayed the risks. The company's founder said it involved a small targeting error unlikely to cause problems for patients.

A company notification sent to a U.S. clinic warned the problem could cause "injury or death."

Brainlab officials said they believed the malfunction occurred in just seven models in use worldwide. Four hospitals in France, two in the United States, and one in Spain have the equipment, but the company would not name the U.S. hospitals. Brainlab would say only that U.S. health authorities and the affected U.S. hospitals, in Ohio and Washington state, were notified.

An official at the Cleveland Clinic said his center received an "urgent medical device" notice from Brainlab about a week ago.

Martin Weinhouse, a physics expert at Cleveland Clinic, said the problem involved a small aiming error that can occur when Brainlab's Novalis system is used with another manufacturer's head frame, a ring-shaped device that circles the head and is used in delivering radiation.

Weinhouse said the error involved a deviation of about 1.25 millimeters, which is similar to variations inherent in the delivery system, and he did not believe it would lead to serious problems.

Brainlab founder and chief executive officer Stefan Vilsmeier told the Associated Press that because doctors typically allow a certain margin of error in targeting a tumor with radiation, "we don't expect any problems with the patients."

The Food and Drug Administration had no immediate comment.

Some 550 Brainlab radiotherapy machines are in use worldwide - the largest number in the United States.

Radiotherapy treatment involves a one-time blast by a high-energy X-ray aimed from several sources and focused on one point to kill the tumor. It typically has a margin of error of 0.8 millimeters when used on brain tumors.

In malfunctioning French machines, the margin was found to have increased to 1.25 millimeters, Brainlab said.

"This security margin is always used to avoid critical organs: very important parts of the brain such as those that control sight," said Christian Carrie, coordinator of radiotherapy at the Leon Berard Cancer Center in Lyon.

Carrie said that with a security margin, "we cannot be sure, but we can hope" to avoid killing healthy brain tissue "even if there is a problem with the targeting of 1 millimeter."

source:www.philly.com