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The virtual colonoscopy appears (finally) to have come of age! My husband and I read about it yesterday in our separate newspapers. (He reads "The Wall Street Journal" and I read "The New York Times".) He agreed that the Times did a better job on this story, so here is the Times'' version 
.
December 2, 2003
A Gentler Type of Colonoscopy Proves Effective
By GINA KOLATA
A new study finds that virtual colonoscopy, a method that uses a C.T. scanner for colon cancer screening, can be just as effective as traditional colonoscopy in finding polyps, the mushroomlike growths from which most cancers arise.
Patients having the 15-minute virtual screening test simply lie down and hold their breath for about 10 seconds, exhale, then hold their breath again while a C.T. scanner X-rays their colons, creating detailed, three-dimensional images of the walls. With traditional colonoscopy, patients are sedated while a doctor threads a long flexible tube into the colon, spending half an hour viewing its walls in much the same sort of detail. Then they wait in a recovery room for about an hour as the sedative wears off.
With virtual colonoscopy, said Dr. Perry J. Pickhardt, a radiology professor at the University of Wisconsin and director of the new study, "it is as though you are flying through this virtual reality." As the doctor watches the screen, "the polyps pop up," he said. "It''s as though you''re doing a regular colonoscopy."
The study included 1,233 people ages 50 to 79 who agreed to have a virtual colonoscopy and then, immediately afterward, a traditional one for comparison. The doctors doing the traditional colonoscopies did not know what the virtual ones had found.
Each method, the investigators report, found more than 90 percent of polyps at least 8 millimeters in diameter and about 88 percent of those at least 6 millimeters across.
The study, which will be published in Thursday''s issue of the New England Journal of Medicine, was released yesterday because it is being presented at a meeting of the Radiological Society of North America.
Medical experts praised the results.
"It puts virtual colonoscopy right up there with the gold standard, optical colonoscopy," said Dr. J. Thomas Lamont, who is chief of gastroenterology at Beth Israel Medical School. Dr. Lamont wrote an editorial accompanying the paper.
Virtual colonoscopy has been around for nearly a decade, but it has never been on the recommended list of screening tests. In previous studies it missed as many as half of even the large polyps that are most worrisome. The difference this time, said Dr. Pickhardt, is in the method.
The study researchers used a computer program that revealed the colon in three dimensions. Most other virtual colonoscopy has involved two-dimensional slices created from C.T. scan images. The patients in the new study also drank a fluid that labeled fecal material so doctors did not confuse it with polyps.
"It really matters what method you''re using and how you prepare the colon," Dr. Pickhardt said.
But, he cautioned, virtual colonoscopy patients still must undergo the onerous process of cleansing their colons of fecal material before the test and they must insert a small tube into their rectums and pump air into their colons during the scan, a procedure that can be uncomfortable. And if the scan finds polyps, they may need a traditional colonoscopy to cut them out.
Most health insurers also do not pay for the procedure. "What is being charged varies from $500 to over $2,000," Dr. Pickhardt said. "Patients are paying out of pocket. It''s what the market allows."
Doctors said that virtual colonoscopy appeals to some who shun other screening methods. Many people abhor the idea of sedation, used in traditional colonoscopy. Others worry about the risks — most notably a chance of one in several thousand that the colon will be perforated. That requires major emergency abdominal surgery.
In the new study, about 54 percent of patients said regular colonoscopy was more uncomfortable than virtual, about 38 percent said virtual was more uncomfortable and about 8 percent were undecided. But almost 70 percent of the patients said virtual colonoscopy was more convenient.
"Some of the appeal of virtual colonoscopy is its name," said Dr. Douglas K. Rex, a professor of medicine at Indiana University and president of the American College of Gastroenterology. He added that many experts call it "C.T. colonography" instead. "Some of the appeal goes away when you call it that name," he said.
For all its promise, medical experts say, there are problems to be worked out with virtual colonoscopy. One is when to refer such patients for regular colonoscopy. In general, the larger the polyp, the more worrisome it is. But do you use 10 millimeters in diameter as a cutoff point? If so, then 3 to 5 percent of patients will need a regular colonoscopy to cut out the polyps found on a virtual one. Do you choose six to nine millimeters? Then at least 30 percent will need traditional colonoscopy.
Colon cancer experts debate the importance of lesions as small as six to nine millimeters, but with conventional colonoscopy, doctors often cut off every polyp they find, so size has not been an issue. It becomes one with virtual colonoscopy.
"Do you ignore the six- to nine-millimeter polyps or do you repeat the test?" Dr. Rex asked. "If you repeat it, when? In 5 years, in 10 years? I don''t think the public will accept the idea that they can have a six- to nine-millimeter polyp sitting in their colon, ignored."
The question of who gets referred for a traditional colonoscopy "may say more about us than about the science," said Dr. Russell Harris, a professor of medicine at the University of North Carolina.
"In our zeal to be sure every single polyp is eradicated," he said, "suddenly, you have increased the costs and increased the possibility of harming someone. In our attempt to reduce the downside of colon cancer screening, we may end up increasing the risks."
Dr. Pickhardt said, "It''s an educational issue." Most very tiny polyps are inconsequential, he explained, adding that virtually none are cancerous and that many shrink on their own. Those that do not shrink grow so slowly that they can be checked again in a few years. "The tiny risk of a small polyp doesn''t outweigh the risk of undergoing an invasive procedure to remove it," he said.
But he and others are optimistic that if the new virtual colonoscopy study can be replicated, the public may soon have another option for colon cancer screening. And that, colon cancer experts hope, may encourage more people to be screened.
Many simply ignore the public health advice to have colon cancer screening starting at age 50, finding the available options unappealing.
"Boy, do we need a better test," Dr. Harris said. "The tests we have now all have problems."
Professional groups recommend regular screening with any of four methods. The most accurate, most invasive and most expensive, at about $2,000, is colonoscopy, which must be repeated every decade.
The other methods include sigmoidoscopy, which costs only a few hundred dollars and does not require sedation. But it examines only the lower half of the colon, where most cancers arise, and it must be repeated every five years. Patients can have barium enemas, which cost several hundred dollars and must be repeated every five years. They are not as effective as colonoscopies and sigmoidoscopies in finding polyps.
The fourth choice is a fecal occult blood test, which costs about $20 and looks for traces of blood in stool that can arise when polyps ooze blood. Since it misses many polyps, it should be repeated every year or two. Rigorous studies show that it reduces the colon cancer death rate, although doctors believe the other tests have the same effect.
"It''s important that we be working on new approaches to colorectal cancer screening because we have low adherence rates," Dr. Rex said. "As you have more options, you may have something that will appeal to everyone."
.December 2, 2003
A Gentler Type of Colonoscopy Proves Effective
By GINA KOLATA
A new study finds that virtual colonoscopy, a method that uses a C.T. scanner for colon cancer screening, can be just as effective as traditional colonoscopy in finding polyps, the mushroomlike growths from which most cancers arise.
Patients having the 15-minute virtual screening test simply lie down and hold their breath for about 10 seconds, exhale, then hold their breath again while a C.T. scanner X-rays their colons, creating detailed, three-dimensional images of the walls. With traditional colonoscopy, patients are sedated while a doctor threads a long flexible tube into the colon, spending half an hour viewing its walls in much the same sort of detail. Then they wait in a recovery room for about an hour as the sedative wears off.
With virtual colonoscopy, said Dr. Perry J. Pickhardt, a radiology professor at the University of Wisconsin and director of the new study, "it is as though you are flying through this virtual reality." As the doctor watches the screen, "the polyps pop up," he said. "It''s as though you''re doing a regular colonoscopy."
The study included 1,233 people ages 50 to 79 who agreed to have a virtual colonoscopy and then, immediately afterward, a traditional one for comparison. The doctors doing the traditional colonoscopies did not know what the virtual ones had found.
Each method, the investigators report, found more than 90 percent of polyps at least 8 millimeters in diameter and about 88 percent of those at least 6 millimeters across.
The study, which will be published in Thursday''s issue of the New England Journal of Medicine, was released yesterday because it is being presented at a meeting of the Radiological Society of North America.
Medical experts praised the results.
"It puts virtual colonoscopy right up there with the gold standard, optical colonoscopy," said Dr. J. Thomas Lamont, who is chief of gastroenterology at Beth Israel Medical School. Dr. Lamont wrote an editorial accompanying the paper.
Virtual colonoscopy has been around for nearly a decade, but it has never been on the recommended list of screening tests. In previous studies it missed as many as half of even the large polyps that are most worrisome. The difference this time, said Dr. Pickhardt, is in the method.
The study researchers used a computer program that revealed the colon in three dimensions. Most other virtual colonoscopy has involved two-dimensional slices created from C.T. scan images. The patients in the new study also drank a fluid that labeled fecal material so doctors did not confuse it with polyps.
"It really matters what method you''re using and how you prepare the colon," Dr. Pickhardt said.
But, he cautioned, virtual colonoscopy patients still must undergo the onerous process of cleansing their colons of fecal material before the test and they must insert a small tube into their rectums and pump air into their colons during the scan, a procedure that can be uncomfortable. And if the scan finds polyps, they may need a traditional colonoscopy to cut them out.
Most health insurers also do not pay for the procedure. "What is being charged varies from $500 to over $2,000," Dr. Pickhardt said. "Patients are paying out of pocket. It''s what the market allows."
Doctors said that virtual colonoscopy appeals to some who shun other screening methods. Many people abhor the idea of sedation, used in traditional colonoscopy. Others worry about the risks — most notably a chance of one in several thousand that the colon will be perforated. That requires major emergency abdominal surgery.
In the new study, about 54 percent of patients said regular colonoscopy was more uncomfortable than virtual, about 38 percent said virtual was more uncomfortable and about 8 percent were undecided. But almost 70 percent of the patients said virtual colonoscopy was more convenient.
"Some of the appeal of virtual colonoscopy is its name," said Dr. Douglas K. Rex, a professor of medicine at Indiana University and president of the American College of Gastroenterology. He added that many experts call it "C.T. colonography" instead. "Some of the appeal goes away when you call it that name," he said.
For all its promise, medical experts say, there are problems to be worked out with virtual colonoscopy. One is when to refer such patients for regular colonoscopy. In general, the larger the polyp, the more worrisome it is. But do you use 10 millimeters in diameter as a cutoff point? If so, then 3 to 5 percent of patients will need a regular colonoscopy to cut out the polyps found on a virtual one. Do you choose six to nine millimeters? Then at least 30 percent will need traditional colonoscopy.
Colon cancer experts debate the importance of lesions as small as six to nine millimeters, but with conventional colonoscopy, doctors often cut off every polyp they find, so size has not been an issue. It becomes one with virtual colonoscopy.
"Do you ignore the six- to nine-millimeter polyps or do you repeat the test?" Dr. Rex asked. "If you repeat it, when? In 5 years, in 10 years? I don''t think the public will accept the idea that they can have a six- to nine-millimeter polyp sitting in their colon, ignored."
The question of who gets referred for a traditional colonoscopy "may say more about us than about the science," said Dr. Russell Harris, a professor of medicine at the University of North Carolina.
"In our zeal to be sure every single polyp is eradicated," he said, "suddenly, you have increased the costs and increased the possibility of harming someone. In our attempt to reduce the downside of colon cancer screening, we may end up increasing the risks."
Dr. Pickhardt said, "It''s an educational issue." Most very tiny polyps are inconsequential, he explained, adding that virtually none are cancerous and that many shrink on their own. Those that do not shrink grow so slowly that they can be checked again in a few years. "The tiny risk of a small polyp doesn''t outweigh the risk of undergoing an invasive procedure to remove it," he said.
But he and others are optimistic that if the new virtual colonoscopy study can be replicated, the public may soon have another option for colon cancer screening. And that, colon cancer experts hope, may encourage more people to be screened.
Many simply ignore the public health advice to have colon cancer screening starting at age 50, finding the available options unappealing.
"Boy, do we need a better test," Dr. Harris said. "The tests we have now all have problems."
Professional groups recommend regular screening with any of four methods. The most accurate, most invasive and most expensive, at about $2,000, is colonoscopy, which must be repeated every decade.
The other methods include sigmoidoscopy, which costs only a few hundred dollars and does not require sedation. But it examines only the lower half of the colon, where most cancers arise, and it must be repeated every five years. Patients can have barium enemas, which cost several hundred dollars and must be repeated every five years. They are not as effective as colonoscopies and sigmoidoscopies in finding polyps.
The fourth choice is a fecal occult blood test, which costs about $20 and looks for traces of blood in stool that can arise when polyps ooze blood. Since it misses many polyps, it should be repeated every year or two. Rigorous studies show that it reduces the colon cancer death rate, although doctors believe the other tests have the same effect.
"It''s important that we be working on new approaches to colorectal cancer screening because we have low adherence rates," Dr. Rex said. "As you have more options, you may have something that will appeal to everyone."
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