Safety and Effectiveness of Using CyberKnife on Prostate Cancer Patients Debated

By Rob Stein
Washington Post Staff Writer
Friday, November 28, 2008

When Georgetown University Hospital bought a new high-tech system in 2001 to treat patients with radiation, doctors at first used the computerized, robotic device only for brain and spinal tumors that would be difficult if not impossible to fight any other way.

But Georgetown, along with Virginia Hospital Center and others around the country, is now aggressively marketing the $4 million machine, known as the CyberKnife, for early prostate cancer, one of the most common cancers. That trend has sparked an intense debate about whether it represents an important advancement or the latest example of an expensive and potentially profitable new technology proliferating too soon.

While its advocates say the CyberKnife offers prostate cancer patients a safe and effective -- and much more convenient -- alternative to traditional radiation treatment, many experts fear that it could leave many men unnecessarily vulnerable to recurrences or potentially serious complications.

"This is really pushing the envelope," said Anthony L. Zietman, president-elect of the American Society for Therapeutic Radiology and Oncology (ASTRO). "It might be as good and more convenient. It may be better and more convenient. But it could turn out to be a disaster. No one knows."

Proponents argue that enough evidence has accumulated to make them confident that the approach is at least as good as standard therapies and that it can prevent unnecessary deaths by making treatment less daunting. Because the CyberKnife can more precisely target tumors with higher doses of radiation, it could prove even safer and more effective, they say.

"I'm very excited about this," said Sean P. Collins, a Georgetown radiation oncologist. "I think it's an important addition to the treatment of prostate cancer. We'll definitely save more lives."

Some critics worry, however, that the push to expand the use of the CyberKnife may be motivated in part by financial incentives: The manufacturer wants to sell more machines, hospitals and private practices want to recover the cost of the systems, and urologists can receive a Medicare payment of about $1,200 for each patient who opts for the therapy.

"Unfortunately, it often comes down to the money," said Louis Potters, who chairs ASTRO's Health Policy Council. "Prostate cancer is so common that it represents low-hanging fruit in terms of revenue opportunities."

The debate illustrates the issues that can arise when costly new medical technologies arrive before researchers have thoroughly evaluated their risks and benefits.

"You have a lot of factors that converge to make something take off," said Diane C. Robertson of the ECRI Institute, an independent, nonprofit organization that evaluates medical technologies. "If you have a promising technology coupled with favorable reimbursement coupled with hospitals' need to be competitive, that's enough to give something a push."

Prostate cancer strikes more than 186,000 American men each year and kills more than 28,000, making it the second most common cancer after skin cancer and the second leading cancer killer after lung cancer among men.

Because the tumors often grow slowly, many men can choose to have doctors closely monitor them. For those who decide to treat the cancer, the most common approaches are surgery to remove the prostate or various forms of radiation, including radioactive "seeds" that are implanted in the gland or "external beam" radiation that subjects the tumor to relatively low doses spread over about 40 fifteen-minute sessions. All the treatments can produce complications, including incontinence, bleeding, problems urinating and impotence.

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