A technique that involves injecting radioactive seeds into the prostate to kill cancer may deliver an inadequate radiation dose to the prostate more than half the time, according to a doctor who trains physicians in the procedure.

"Based on what's been published over the last ten years, I'd say as many as 50 percent of patients in the U.S. get an adequate implant," says Nelson Stone, M.D., a urologist and clinical professor of urology, radiation oncology and oncological sciences at Mount Sinai Medical Center in New York City.

Dr. Stone, who is also medical director of Prologics, a company that operates and services radiation treatment centers in the United States, believes a careful review of the medical literature suggests that this life-saving procedure isn't working as well as it should.

In brachytherapy (from the Greek word brachy, meaning "short distance") doctors typically use an ultrasound to guide the placement of tiny radioactive seeds into the prostate. Once there, radiation emitted from the implants can eliminate cancers growing in the organ.

While highly effective if used properly, errors can be disastrous. Seeds intended for the prostate that miss might end up in the bladder, urethra or rectum. There, the seeds could cause serious radiation-induced injury. According to Dr. Stone, botched procedures can result in anal bleeding, fistulas and urinary incontinence.

Worse than the direct side effects, though, is that radioactive seeds lodged outside the prostate can't fully expose the cancers to radiation, which can lead to cancer recurrence, according to Dr. Stone.

What dosimetry studies reveal

After looking over the relevant literature for an upcoming article, Dr. Stone concludes these serious medical errors are startlingly common.

As Dr. Stone explains, the success of a procedure is generally determined by a post-implant dosimetry study to measure how much of the radiation dose was delivered to the prostate, and how much to outlying areas. In this, the key metric is the D-90, or the radiation dose to 90 percent of the prostate.

"That number, the dose to 90 percent of the prostate, has been highly correlated with the cure rate, in terms of eradicating prostate cancer," Dr. Stone says.

Typically, a minimum D-90 for the most common isotope used (I-125) should be 140 Gy. This dose is held as the benchmark to achieve for controlling cancer, according to Dr. Stone. But in his research he has discovered that as many as 50 percent of the brachytherapy procedures performed in the United States fail to reach 140 Gy. This means that one half the patients may be getting too low a dose.

"Furthermore, these data are derived mostly from academic centers, not community hospitals where the majority of the procedures in the US are performed," Dr. Stone notes, so the true rate of inadequately performed procedures could be higher.

Bad publicity

Evidence of botched brachytherapy procedures is not quietly lingering in the pages of medical journals; it has begun to make headlines. Last week the University of Pennsylvania admitted in January a man undergoing brachytherapy to treat prostate cancer had seeds that missed the prostate.

The error hearkened back to similar bad news Penn received last summer, when the New York Times uncovered a troubled Penn-administered brachytherapy program at the Philadelphia Veterans Administration hospital. According to the Times, over a six-year period a doctor there bungled 92 out of 116 brachytherapy procedures.

And on Thursday, the U.S. Nuclear Regulatory Commission, which found around eight violations during their initial investigation of the hospital, including the VA's failure to properly train personnel to identify and report problems, announced a proposed $227,500 fine against the VA, the second largest the agency has ever proposed for a medical error.

Lack of training

Echoing the NRC findings, Dr. Stone believes the problem is one of lack of training. "There are no certifications for any of the new procedures out there," he notes.

In learning how to use a new technique, such as prostate brachytherapy, most doctors attend a seminar, then go back to their hospital and begin to practice it after only one or two supervised procedures, Dr. Stone says.

"When I was in med school, the axiom for learning was 'See one, do one, teach one,'" he notes. "You see a procedure, you do one, then you can teach one." But now Dr. Stone believes that model is outdated. "Today, procedures are so complicated that no longer fits," he argues. And when doctors stick with this traditional method Dr. Stone believes patients "suffer the learning curve of the physicians."

Currently, for prostate brachytherapy, the field is only regulated by hospital bylaws, which Dr. Stone believes are inadequate. "Unfortunately, the hospitals are not really equipped to understand what is necessary to make physicians proficient," Dr. Stone argues.

What Dr. Stone believes works is rigorous hands-on training. And over the last 15 years, Dr. Stone says he has trained around 1,500 physicians world-wide in prostate brachytherapy, including around 10 percent of all doctors in the U.S. who perform that procedure. Dr. Stone and his colleagues have published on the success of this training methodology.

"I try to short-circuit that learning curve by going into the OR and hand-hold the physicians until they get the level of expertise and they're competent on their own," he says. For the last four years, through a company called Nihon Medi-Physics, Dr. Stone has also been traveling to Japan to train physicians there. According to Dr. Stone, by the time he's finished with his program through Nihon he will have trained close to 75 percent of all Japanese physicians who perform the procedure.

Lessons from Japan

When asked why the Japanese seem so eager to absorb his training, Dr. Stone attributes it to differences in medical culture between Japan and the United States.

In Japan, the health system is partly nationalized (with health insurance, which is mandatory for all Japanese, provided by employers or the government). Doctors are directly salaried by the hospital, according to Dr. Stone. "They all get paid the same salary and work the same hours. There's a different philosophy when it comes to the approach to medicine," he says.

But all is not entirely rosy. Although the Japanese are believed to have lower rates of prostate cancer, Dr. Stone says once diagnosed three-fourths of Japanese men have advanced disease, which is more likely to be fatal.

"The reason is they have no early detection program," he says. "There's no PSA [Prostate-Specific Antigen test] screening, whereas in America it has been going on since 1990." In the U.S., Dr. Stone says more than 80 percent of men will have had their PSA levels checked by the time they turn 57. This in turn means when cancer is discovered, it is usually smaller and more susceptible to treatment and cure.

In fact, in America, the mortality rate from prostate cancer has declined over the last five years. "It used to be 42,000 deaths [a year], now it's 27,000," says Dr. Stone. But in Japan, the outlook is grimmer. "[The death rate has] been going up, and going up substantially over the last number of years," observes Dr. Stone.