Doctors who own radiation equipment three times more likely to recommend the therapy to prostate cancer patients

If you’ve got it, you tend to use it—at least when it comes to radiology equipment, according to a study by Dr. Jean Mitchell at Georgetown University, published recently in the New England Journal of Medicine.

The study showed that prostate cancer patients treated by urologists who purchase their own in-house radiation equipment are much more likely to undergo radiation treatment such as intensity-modulated radiation therapy (IMRT) than patients who are treated by doctors who do not own their own radiation equipment.

The study analyzed use among doctors in two sample groups. One sample was of 70 private practice urology groups, equally divided between those who owned their equipment and those who didn’t. The other sample was of urologists at 11 National Comprehensive Cancer Network (NCCN) centers who did not own their own equipment, matched with 11 private practice groups that did. Combing through Medicare claims, Mitchell discovered that those doctors who did not own IMRT technology prescribed the treatment for 15.6 percent of their patients in 2010 while doctors at NCCN referred approximately 8 percent of patients. Among doctors who did own their own IMRT equipment, the referral rate was as high as 44 percent.

IMRT has a high reimbursement rate over less expensive therapies and a price tag of approximately $2 million. Mitchell’s conclusion is that profit incentive may contribute to overuse of IMRT among self-referring physicians.

“Financial pressures induced by substantial startup costs may likewise have prompted physician-owners to recommend IMRT in lieu of alternative treatments,” she wrote.

In recognition of conflict of interest over profit and encouragement of over-utilization of services, which in turn drives up health care costs, physicians are prevented by law from referring Medicare and Medicaid patients for treatment in facilities that the doctors own; however, some equipment, including radiation equipment, is exempt from this law.

Guarding against over-referral and over-diagnosis

Prostate cancer treatment is controversial. Many men diagnosed with small cancers will not benefit from treatment because the cancer grows slowly enough that it will not cause a problem; however, there is a general consensus that only a very tiny fraction of men with low PSA levels and small, low-grade cancers will die of their disease, but most of these men opt for treatment anyway. According to Dr. Ruth Etzioni, who studies prostate cancer modeling, screening and outcomes at Fred Hutchinson Cancer Research Center, it is important for patients diagnosed with prostate cancer to find out about their options prior to treatment.

“The most important thing for a patient to find out is their chance of being over-diagnosed and thus over-treated,” she said. “Prostate cancer patients have many options for treatment, but the first question they need to ask is whether they actually require treatment at all. Prostate cancer is a very heterogeneous disease and most cancers that are detected are low risk with regard to having a bad outcome. If the patient is over 70 years old, which is the age when most men are diagnosed, there is a very high chance that they will never have a bad outcome from the cancer—there is up to an 80-percent chance they may not have any symptoms even if they don’t get treated . If they have a low-risk cancer, and are merely monitored, there is something like a 2 to 3 percent chance of dying from it over 20 years.”

Additionally, she said that a patient needs to find out how his diagnosis fits in with the rest of their health profile, taking into consideration his health. “If a man comes to the urologist with diabetes and high blood pressure and low-risk prostate cancer, the chances are that the prostate cancer is not likely to be the thing to worry about,” she said.

If treatment is deemed necessary, there are numerous options available: radiation, hormone therapy or surgery. Etzioni said that data on which therapy is best is not clear. “It’s important to understand that a lot of the various treatments have never been tested head to head in randomized trials,” she said. “Observational studies show that surgery is better than radiation for cancer which is localized, but it’s hard to get unbiased comparisons in observational studies because we don’t have the information on why patients get a particular treatment.”  

Even under the umbrella of “radiation therapy” she said there are a variety of treatment options and that few people understand how complex radiation therapies are. “External radiation is extremely complicated because the radiation has to pass through healthy tissue to get to the tumor and the doctors have to work hard to minimize damage to that tissue. Every patient is different and they have to map exactly where the diseased part is to focus the beam. IMRT is not just a machine but a whole back office doing physics and calculations and software that allows you to perfectly visualize and direct the beam,” she said.

If radiation therapy is recommended, Etzioni suggests patients find out which type of radiation is recommended and why.  “And, of course, given the over-referral phenomena, it’s a good idea to ask whether the doctor owns the radiation equipment,” she said.