Advertisement
(Photo: http://www.newscom.com/cgi-bin/prnh/20080917/NYW148 )
CT colonography employs virtual reality technology to produce athree-dimensional visualization that permits a thorough and minimally invasiveevaluation of the entire colon and rectum. The ACRIN trial, sponsored by theNational Cancer Institute (NCI), part of the National Institutes of Health(NIH), enrolled more than 2,600 patients at 15 sites nationwide. It is thelargest multi-center study to compare the accuracy of state-of-the-art CTcolonography to the gold standard of conventional colonoscopy. The results ofthis study are published in the Sept. 18, 2008, issue of the New EnglandJournal of Medicine.
Advertisement
"CT colonography could be adopted into the mainstream of clinical practiceas a primary option for colorectal cancer screening. We hope that thisadditional, less-invasive option for cancer screening will lead more people toget screened and will ultimately result in fewer deaths from colorectalcancer," said ACRIN National CT Colonography Trial principal investigator C.Daniel Johnson, M.D., of the Mayo Clinic in Scottsdale, Ariz.
Colorectal cancer is the third most frequently diagnosed cancer and secondleading cause of cancer death in men and women in the United States. Althoughscreening recommendations vary somewhat, many recommend that adults aged 50and older in the general population receive a colonoscopy every 10 years ormore frequently, depending on known risk factors. Yet, despite the knownbenefits of screening, studies indicate that the majority of Americans age 50and older are not being screened for the disease.
"Imaging advances such as virtual colonoscopy are an important stepforward that could potentially increase the number of people who would agreeto be screened. We hope, through continued imaging research and thedevelopment of molecular diagnostic techniques, that we will continue toimprove our screening options in the years ahead and, as a result, continue tosee a decline in the incidence of colorectal cancer," said NCI Director JohnE. Niederhuber, M.D.
"Previous single-site studies had indicated that CT colonography heldpromise in screening for colorectal cancer due to its accuracy, safety,cost-effectiveness, and patient acceptability. However, validation of thetechnique across multiple centers and radiologists was needed to provide moreevidence of the exam's viability. The ACRIN trial has now validated that CTcolonography could serve as an initial screening exam for the population inwhich screening is indicated," said Mei-Hsiu Chen, Ph.D., trial statistician,ACRIN Biostatistics and Data Management Center, Brown University, Providence,R.I.
In the ACRIN trial, the CT colonography findings were evaluated usingstandard colonoscopy as the reference standard. CT colonography was found tobe highly accurate for the detection of intermediate and large polyps. Ninetypercent of the polyps 1 centimeter or larger were detected by CT colonography.Even polyps as small as one half centimeter were detected by CT colonographywith a high degree of accuracy. Since most colon cancers develop from polyps,and screening to find and remove these polyps can prevent colon cancer, anopportunity exists to save lives with early detection.
"There are clearly clinical settings in which CT colonography,colonoscopy, or both tests in combination offer distinct advantages. The mostimportant advice we can g
