A newer 'virtual' model is challenging the traditional method
FRIDAY, Oct. 12 (HealthDay News) -- Two recent studies comparing the use of conventional (optical) colonoscopy and CT (virtual) colonoscopy for colorectal cancer screening may raise questions among people considering the test, says the American College of Gastroenterology (ACG).
The studies included a large multi-center trial called ACRIN that was sponsored by the U.S. National Institutes of Health and a University of Wisconsin study published in the New England Journal of Medicine. Both trials compared the accuracy of CT colonoscopy to conventional colonoscopy (the current gold standard for colorectal cancer screening) in detecting polyps or cancer in the colon.
In order to help inform the public, the ACG has developed an FAQ (frequently asked questions) resource describing both colonoscopy techniques.
Conventional colonoscopy involves insertion of a flexible tube into the rectum. The tube, which carries a tiny camera, allows the doctor to directly view the entire colon and to detect and remove suspicious polyps. Three studies found that this method prevents about 80 percent of colorectal cancers from developing, according to the ACG.
In CT colonoscopy, air is pumped into the colon until it's fully distended and a CT scan is used to examine the colon. Studies suggest that between 30 percent and 50 percent of patients who have a CT colonoscopy will need a conventional colonoscopy to remove suspicious polyps.
On average, research has shown that CT colonoscopy is inferior to regular colonoscopy for detection of colon polyps, the ACG said.
Both types of colonoscopy require the same bowel-cleansing regimen.
The U.S. National Cancer Institute has more about colorectal cancer screening.
-- Robert Preidt
SOURCE: American College of Gastroenterology, news release, Oct. 8, 2007
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