A New, Massive Study Demonstrates that Virtual Colonoscopy Can Be Accurate

About 150,000 Americans will be diagnosed with some form of colorectal cancer in 2008, and an additional 49,000 people will die from colon or rectal cancer this year, making this horrible form of the disease the second most deadly cancer in the world. To detect colorectal cancer, patients must be screened. Traditionally, screening demanded an invasive and painful procedure, but now an extensive study of nearly 2,600 people has demonstrated that a painless, computer-aided exam can accurately detect colorectal cancer as much as 90 percent of the time.

Computerized tomographic (CT) colonography, which is often called virtual colonoscopy, uses virtual reality- similar to video game or movie-making technology-to produce a three-dimensional rendering of a given patient's entire colon and rectum , detecting cancerous lesions and adenomas. But until recently it was not known how statistically accurate a CT colonography was in screening asymptomatic adults for disease.

Dr. C. Daniel Johnson and more than a dozen his colleagues released the results of their recent, 15-site and 2,600 person, American College of Radiology Imaging Network (ACRIN) National CT Colonography Trial in the September 18, 2008 issue of the New England Journal of Medicine. The study aimed to determining just how accurate CT colonography is as a screening tool.

"CT colonography could be adopted into the mainstream of clinical practice as a primary option for colorectal cancer screening. We hope that this additional, less-invasive option for cancer screening will lead more people to get screened and will ultimately result in fewer deaths from colorectal cancer," said Johnson.

The study, which focused on healthy participants 50 years old or older at 15 locations around the United States, found the CT Colonography detected large (10mm or larger in diameter) adenomas and adenocarcinomas 90 percent of the time. Smaller adenomas (6mm or larger in diameter) were correctly identified about 78 percent of the time, making CT Colonography comparable to traditional and invasive colonoscopy.