miércoles, 10 de agosto de 2011

Tracking the Rise of Robotic Surgery for Prostate Cancer ► NCI Cancer Bulletin for August 9, 2011 - National Cancer Institute


full-text ►NCI Cancer Bulletin for August 9, 2011 - National Cancer Institute: "Tracking the Rise of Robotic Surgery for Prostate Cancer


Drs. Peter Pinto and Gennady Bratslavsky of NCI's Urologic Oncology Branch prep a prostatectomy patient for surgery with the da Vinci Surgical System. (Photo by Bill Branson, NIH) Drs. Peter Pinto and Gennady Bratslavsky of NCI's Urologic Oncology Branch prep a prostatectomy patient for surgery with the da Vinci Surgical System. (Photo by Bill Branson, NIH)

In the 11 years since the Food and Drug Administration (FDA) approved the first robotic surgical system for conducting abdominal and pelvic surgeries, its use has skyrocketed. The da Vinci Surgical System is now used to perform as many as 4 out of 5 radical prostatectomies in the United States. The robotic system is also increasingly being used to treat other cancers, including gynecologic and head and neck cancers. According to da Vinci's manufacturer, Intuitive Surgical, Inc., more than 1,000 of the robotic systems are in hospitals across the country.

Several recent studies suggest that the ascendance of robotic prostatectomy has had numerous consequences, including a mass migration of prostate cancer patients to hospitals with robotic systems and an overall increase in the number of prostatectomies performed each year. The latter trend has raised some concern because it coincides with a period during which prostate cancer incidence has declined slightly.

How robotic prostatectomy proliferated so quickly, and what it means for patients and the health care system, is still a matter of study and debate. But the shift appears to have altered the surgical treatment of prostate cancer permanently, observed urologic surgeon Dr. Hugh Lavery of the Mount Sinai Medical Center in New York.

'I think that traditional open and laparoscopic prostatectomies have faded,' Dr. Lavery said. The available data indicate that patients and surgeons 'are pushing for the robots,' he added, 'and they're getting them.'

A Compelling Technology, an Intrigued Audience

Type 'robotic surgery prostate cancer' into an Internet search engine, and the results will typically include glowing testimonials from patients who were treated with robotic surgery and videos of da Vinci's surgical instruments roaming about the peritoneal cavity suturing, cutting through tissue, removing fat. In these videos, the surgeon is on the other side of the room, head buried in a console, and hands at the robot's controls, maneuvering the instruments with the aid of a camera that offers a crisp, 3-dimensional image of the surgical field. (Read more about how the robotic system works.)
Dr. Peter Pinto sits at the da Vinci robot console to perform minimally invasive prostate surgery. (Photo by Bill Branson, NIH) Dr. Peter Pinto sits at the da Vinci robot console to perform minimally invasive prostate surgery. (Photo by Bill Branson, NIH) [Enlarge]

The Internet videos are just one component of the extensive marketing campaign behind da Vinci by individual hospitals and the system's manufacturer. A study of 400 hospital websites, published online in May, found that 37 percent of the sites featured robotic surgery on the homepage, 61 percent used stock text provided by the robot's manufacturer, and nearly one in three sites had claims that robotic procedures led to improved cancer control.

'The tendency is to associate better technology with better care,' explained the study's lead investigator, Dr. Marty Makary of the Johns Hopkins University School of Medicine.

Dr. Makary said he performs most operations, including complex pancreas surgery, laparoscopically because he believes the robot does not offer sufficient tactile feedback and takes more operative time. Traditional laparoscopy, however, is now rarely used for prostatectomies because the procedure is considered technically demanding, according to several researchers. One estimate put the number of laparoscopic prostatectomies each year in the United States at less than 1 percent of the total.

Patients often arrive for an office visit knowing that they want a prostatectomy performed with the robot, said Dr. William Lowrance, a urologic oncologist at the Huntsman Cancer Institute at the University of Utah. 'It may be based on something they saw on the Internet or because of a friend or relative who had a good experience' with robotic surgery, he explained. Approximately 70 percent of the prostatectomies he performs are done with da Vinci.

Patient-to-patient referrals and the fact that the robotic procedure is minimally invasive have been two key drivers of the robot's popularity, said Dr. Ash Tewari, director of the Prostate Cancer Institute at New York-Presbyterian Hospital/Weill Cornell Medical Center, who performs nearly 600 robotic prostatectomies a year.

Several studies have documented that there can be a fairly steep learning curve before surgeons achieve proficiency with the robot. But according to Dr. Warner K. Huh, a gynecologic oncologist and surgeon at the University of Alabama Birmingham Comprehensive Cancer Center, the robot makes it easier to perform many minimally invasive procedures.

'For many surgeons, they feel they can do a minimally invasive procedure more effectively and safely robotically, and I think that's a big reason that it's taken off,' Dr. Huh said.

The growth of robotic surgery is more than just a marketing phenomenon, agreed Dr. Tewari. 'It has been supported with a lot of good science,' he continued. 'We want to make this field better and beyond the hype of robotics.'

What the Science Says So Far

Based on studies to date, there seems to be agreement that robotic surgery is comparable to traditional laparoscopic surgery in terms of blood loss and is superior to open surgery in terms of blood loss and length of hospital stay. Recovery time may also be shorter following robotic surgery than open surgery.

But for the big three outcomes—cancer control, urinary control, and sexual function—there is still no clear answer as to whether one approach is superior to another, Dr. Lowrance noted.

A large, randomized clinical trial comparing any of the approaches seems out of the realm of possibility at this point. At Weill Cornell, Dr. Tewari has approval to conduct a trial comparing robotic prostatectomy with open surgery. But the trial never got off the ground because there are not enough patients willing to be randomly assigned to surgery without the robot, he said.

A randomized trial may not even be that informative. 'Many open surgeons have excellent outcomes, which may be hard to improve upon,' said Dr. Lavery. 'I think that if you have an expert surgeon doing either procedure, you're likely to have an excellent outcome.'

The Peak of the 'Robotic Era'?

The remarkably swift proliferation of the da Vinci system in surgery suites across the United States appears to have had population-wide effects. In a study Dr. Lavery presented at the American Urological Association annual meeting in March, he showed that, from 1997 to 2004, the number of prostatectomies performed in the United States was fairly stable, around 60,000 per year.

From 2005 to 2008, however—what Dr. Lavery and his colleagues called the first true years of the 'robotic era'—the number of prostatectomies and robotic procedures spiked. The number of prostatectomies rose to roughly 88,000 in 2008, and the number of robotic procedures jumped from approximately 9,000 in 2004 to 58,000 in 2008.

The number of prostatectomies rose to roughly 88,000 in 2008, and the number of robotic procedures jumped from approximately 9,000 in 2004 to 58,000 in 2008
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Two other recent analyses that looked at smaller geographic regions—New York, New Jersey, and Pennsylvania in one study and Wisconsin in the other—yielded similar results. But they also showed something else: Hospitals that acquired robots saw a significant increase in the number of radical prostatectomies they performed. At the same time, the number of procedures at hospitals that did not acquire a robot fell.

'The overall result has been a sudden, population-wide, technology-driven centralization of procedures that is without precedent,' wrote Dr. Karyn Stitzenberg of the University of North Carolina Division of Surgical Oncology and her colleagues, who conducted the study in New York, New Jersey, and Pennsylvania.

Whether the rise in the number of procedures has meant that patients who might have been strong candidates for a different treatment, including active surveillance, instead opted for surgery is 'speculative,' Dr. Lowrance said.

'My own feeling is that radical prostatectomy rates in general have probably peaked and are on their way down,' he said, in part because of the increased emphasis on active surveillance in men with localized, low-risk prostate cancer.

Cost Implications Unclear

Another uncertain aspect centers on whether there has been any economic fallout from the increased use of this fairly expensive technology. Hospitals are not paid more for procedures using the robot, despite the fact that its use carries significant extra costs.

The robot itself runs anywhere from $1.2 million to $1.7 million (and many hospitals have several), a required annual maintenance contract is approximately $150,000, and about $2,000 in disposable equipment is required each time the robot is used. Studies have suggested that using the robot may add as much as $4,800 to the cost of each surgery.

Shorter hospital stays and less need for blood transfusions may offset some of these costs, however. In fact, data from a study that Dr. Lowrance and his colleagues have in press indicate that, after adjusting for various factors and excluding the fixed cost of the robot, the cost of robotic prostatectomy and the medical care needed for the ensuing year is comparable to the cost of open surgery and the ensuing year of care in a group of Medicare patients.

Although no other surgical robots have been approved by the FDA, at least two companies are developing similar robotic systems that could, eventually, compete with da Vinci, Dr. Lavery noted, which could reduce costs further.

The dramatic centralization of robotic prostatectomy procedures could be a double-edged sword, Dr. Stitzenberg and her colleagues concluded. A multitude of studies have demonstrated that higher volume is linked to better outcomes, suggesting that having fewer centers performing prostatectomies could improve the overall quality of care. But centralization also raises the specter that access to care could be impaired, particularly in rural areas where market forces could limit the availability of surgeons who can perform the procedure.

The rapid growth of robotic prostatectomy is a proxy for the larger debate about the role of technology in medicine, Dr. Lowrance believes. For example, intensity-modulated radiation therapy and proton-beam therapy—which cost tens of thousands of dollars more than robotic surgery—are also gaining popularity as treatments for localized prostate cancer, even though neither has been shown to produce better outcomes than standard radiation therapy.

'The big question is: How do we balance the uptake of new technology and its cost with the additional [clinical] value it may provide?' he continued. 'It's hard to do those types of studies, but we have to continue to ask whether [a new technology] is always worthwhile.'
—Carmen Phillips


Not Just for the Prostate: Robotic Surgery Makes Inroads in Gynecologic Cancers


The meteoric growth of robotic surgery to treat prostate cancer over the past decade has been mirrored by a similar growth in the treatment of gynecologic cancers, such as cervical and endometrial cancer. (Robotic surgery for gynecologic cancers typically involve a hysterectomy, which may be accompanied by lymph node dissection.)

Minimally invasive surgery with traditional laparoscopy has been a common treatment for gynecologic cancers for two decades, said Dr. Warner Huh of the University of Alabama Birmingham Comprehensive Cancer Center. But many surgeons have switched to the robotic procedure. In particular, the robotic procedure has given surgeons an important new option for treating obese women, Dr. Huh said. Traditional laparoscopy often cannot be performed on obese women, so before robotic surgery these patients typically had to have open surgery.

'An open surgery in these patients is extremely difficult to do,' he said. 'Some of these women had horrific complications related to their incision.'

Obesity rates in Alabama are among the highest in the nation, so robotic surgery has provided an important new clinical option for many women in the state. The average hospital stay following open surgery in obese patients was 4 to 5 days, he said. Now, with the robotic procedure, the average stay is often 24 hours or less. Complication rates have dropped from anywhere between 5 to 10 percent with open surgery to 1 to 2 percent with robotic surgery.

'It's completely changed how we manage these diseases in morbidly obese women,' Dr. Huh said.

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