Updated on September 23, 2022
HealthDay operates under the strictest editorial standards. Our syndicated news content is completely independent of any financial interests, is based solely on industry-respected sources and the latest scientific research, and is carefully fact-checked by a team of industry experts to ensure accuracy.
- All articles are edited and checked for factual accuracy by our Editorial Team prior to being published.
- Unless otherwise noted, all articles focusing on new research are based on studies published in peer-reviewed journals or issued from independent and respected medical associations, academic groups and governmental organizations.
- Each article includes a link or reference to the original source.
- Any known potential conflicts of interest associated with a study or source are made clear to the reader.
Please see our Editorial and Fact-Checking Policy for more detail.Editorial and Fact-Checking Policy
HealthDay Editorial Commitment
HeathDay is committed to maintaining the highest possible levels of impartial editorial standards in the content that we present on our website. All of our articles are chosen independent of any financial interests. Editors and writers make all efforts to clarify any financial ties behind the studies on which we report.
WEDNESDAY, Sept. 8, 2004 (HealthDayNews) -- Virtual colonoscopy, a less invasive method of examining the colon for signs of cancer, can catch polyps missed by a conventional colonoscopy.
A new study involving 1,233 patients who had conventional and virtual colonoscopy on the same day found that, after comparing one set of test results against the other, the standard scoping method tended to miss polyps on the backside of colonic folds and in the low rectum where the scope is inserted.
Overall, the miss rate for standard colonoscopy was 12 percent for 10 millimeter-and-greater polyps -- double previous estimates.
"Really what this provides is, for the first time we have a method to check the accuracy of conventional colonoscopy," said principal investigator Dr. Perry J. Pickhardt, an associate professor of radiology at the University of Wisconsin Medical School in Madison.
Then again, neither method proved foolproof. Each test missed 10 percent to 14 percent of polyps measuring 6 millimeters or greater, the authors report in the Sept. 7 issue of the Annals of Internal Medicine.
But used in tandem, they could boost the detection rate, the findings suggest.
"These are complementary tests. Anything the virtual test missed the conventional test picked up," Pickhardt said.
Colorectal cancer, the second deadliest cancer in the United States after lung cancer, will claim an estimated 56,730 lives this year, according to the American Cancer Society. The good news is it's highly preventable: 90 percent of cases and deaths could be avoided through the use of screening tests, the society says. When detected early, colorectal cancer has a five-year survival rate of nearly 90 percent.
Standard colonoscopy involves the insertion of a thin, flexible, lighted tube called a colonoscope into the rectum. The scope, which is guided through the entire length of the colon, transmits computer images that let a doctor spot abnormalities, such as polyps or inflamed tissue inside the colon. The procedure is widely regarded as the gold standard for detecting polyps.
Virtual colonoscopy, also known as CT colonography, uses powerful computer-assisted X-ray imaging to detect colorectal lesions. Because it is minimally invasive, squeamish patients may find it less offensive. It also avoids the risk of perforating the bowel, a serious complication of conventional colonoscopy.
As the technology evolves, virtual colonoscopy is likely to emerge as a standard screening test, a task force of the American Gastroenterological Association (AGA) concluded in a report last week. But the panel's report in the journal Gastroenterology also cited a number of issues that need to be worked out before the test becomes widely accepted.
"What we've concluded is that virtual colonoscopy has tremendous promise, the technology is evolving and it's getting close to the point that it may be a valid option for screening for colorectal cancer," said Dr. Emmet B. Keeffe, AGA president and a professor of medicine at Stanford University.
To date, studies of virtual colonoscopy have yielded widely varying results, the task force noted. These discrepancies reflect differences in patients' risk for colorectal cancer, variations in equipment, patient preparation and study methods and inconsistencies in the way test results are interpreted.
As recently as April, for example, a study in the Journal of the American Medical Association said the accuracy of virtual colonoscopy in detecting cancers was substantially lower than that of conventional colonoscopy. Researchers used two-dimensional imaging, which may explain the disappointing results, while Pickhardt and his colleagues used state-of-the-art 3-D imaging to detect polyps.
"What we need is to see that this is generalizable," Keeffe said of the latest study. "Will there be other centers that will duplicate the results of Pickhardt?"
Although it's been around for a decade now, with many refinements along the way, virtual colonoscopy is still considered experimental. The American Cancer Society currently does not recommend it for early detection of colorectal cancer, citing a lack of scientific evidence that it's effective, or more effective, than currently recommended screening tests.
It's also not yet widely available, nor do many health insurers pay for it, according to the AGA.
Based in part on Pickhardt's results, Physicians Plus Insurance Corp. in Madison, Wis., announced in June that it would begin covering virtual colonoscopy. Others insurers in that market quickly followed, fueling demand for the procedure.
Pickhardt, a member of the American College of Radiology, is busier than ever and believes it's only a matter of time before virtual colonoscopy catches on nationally.
"Pretty soon," he said, "people are going to realize this makes sense."
Visit the American Cancer Society to learn more about colorectal cancer screening.
This story may be outdated. We suggest some alternatives.
The content contained in this article is over two years old. As such our recommendation is that you reference the articles below for the latest updates on this topic. This article has been left on our site as a matter of historic record. Please contact us at email@example.com with any questions.