A new study published in JAMA on CT colonography or 'virtual' colonoscopy using 2-D imaging finds that this test lacks the sensitivity and specificity of conventional colonoscopy for
colorectal cancer screening. Study co-author and American College of
Gastroenterology President Douglas K. Rex, M.D. is available for interviews.
Findings of a new multicenter study by Cotton et al. published today in the Journal of the American Medical Association comparing standard colonoscopy with CT colonography for the detection of colorectal cancer reveal that this technology, in the form used most often in the United States, while of significant interest, is not presently a viable option for routine colorectal cancer screening. The study utilized abdominal-pelvic CT scanning and the radiologists relied primarily on 2-dimensional images but 3-dimensional "fly-throughs" of the colon that simulate conventional colonoscopy were also evaluated
The study found that the sensitivity of CT colonography for detecting patients with 1 or more lesions sized at least 6 mm was 39 percent, and for lesions sized at least 10 mm it was 55 percent, this compared with 99 percent and 100 percent respectively when examined using conventional colonoscopy also referred to as complete colonoscopy. Only marginal improvements occurred when the 3-dimensional results were evaluated. These findings contrast sharply with findings by Pickhardt et al. recently published in the New England Journal of Medicine in December 2003.