Differing views on virtual colonoscopy accuracy

Apr 14 2004

Demonstrating clearly that not all virtual colonoscopies are equal, the study, published in the December 2003 issue of The New England Journal of Medicine and the American Journal of Roentgenology, found the results found using the Viatronix V3D-Colon system for primary 3D reading to be equal to or better than optical colonoscopy results.

One of the major differentiating factors between the two studies is that Dr Peter Cotton's earlier study was based upon 2D as the primary read while Perry Pickhardt's trial published in the NEJM utilized live 3D as the primary read.

The DOD multi-center trial utilized 1,233 patients as opposed to 615 patients utilized in the recently published study in JAMA (Journal of American Medical Association) conducted by Dr. Peter Cotton. While Dr. Cotton's results have been disappointing, Dr. Perry Pickhardt's results published in NEJM for a much larger patient group are dramatically different. "The study recently published in JAMA was completed in 2001 prior to the time our study began in 2002 and utilized techniques that are outdated," says Dr. Pickhardt. "The main deficiencies in the two are that Dr. Cotton's study relied on primary 2D reading with a lack of oral contrast tagging of barium resulting in poor reading results. Also, it appears that some of the study radiologists were inadequately trained."

The JAMA study reports that the two studies showed "remarkable differences." It further states "that the armed services study [conducted by Dr. Pickhardt] had excellent results." "The combination of electronic cleansing and faster 3-dimensional reconstruction appears promising," concludes the JAMA report.

These features have been available on the Viatronix V3D-Colon system for many years, were used by Dr. Pickhardt's team and led to better outcomes. The Viatronix V3D-Colon technology used in Dr. Pickhardt's NEJM study provides the highest-quality images and the most thorough screening, it offered physicians the most features and greatest ease of use in viewing, manipulating, and examining 100% of the colon to detect and identify polyps, the most common precursor of colon cancer.

In addition, in some cases, V3D-Colon outperformed optical colonoscopy, long considered the "gold standard" of colorectal cancer screening. "After performing a direct comparison of three different virtual colonoscopy systems, we determined that only one system, the Viatronix system, was capable of a primary time efficient 3D reading, which I believe is necessary for sensitive detection of polyps," said Perry J. Pickhardt, M.D., author of the NEJM study, whose credentials include Staff Radiologist for the National Naval Medical Center, Assistant Professor of Radiology for the Uniformed Services University of the Health Sciences, and currently Associate Professor of Radiology at the University of Wisconsin Medical School.

Contrary to the one of the conclusions of the JAMA-published trial, Virtual Colonoscopy has already been proven to be as good as or better than optical colonoscopy. It is readily available for clinical practice today, and there are several training courses being offered by experienced radiologists such as Dr. Perry Pickhardt.

The NEJM trial proved that radiologists adopting this new procedure with "relatively little prior experience" were successfully able to achieve superior results. This NEJM trial was conducted after the one published in JAMA recently, proving that 3D virtual colonoscopy has improved and can now provide the necessary clinical outcomes. Virtual colonoscopy offers a non-invasive alternative to the traditional optical colonoscopy, which requires that a long, flexible fiber-optic scope be inserted into the rectum and maneuvered up to five feet along the length of the colon. V3D-Colon combines the sophisticated computer imaging of a CT scan with breakthrough medical diagnostic software technology to provide a patient- friendly yet incredibly accurate tool for viewing the colon. With the Viatronix system, a thin rubber tube is inserted only one inch into the rectum in order to distend the colon with carbon dioxide. Then, two 20-second CT scans send the patient's data to a computer system, where the Viatronix preprocessor reconstructs a three-dimensional model of the patient's colon and electronically "cleanses" the data of debris (stool) remnants in the colon. The data is then transmitted to a reading station where physicians can automatically conduct an interactive, three-dimensional "fly through" examination of the patient's colon on the computer screen. "With our V3D-Colon procedure, virtually all of the risk and discomfort of a colonoscopy is eliminated, while, equally important, the physician's ability to visualize polyps is greatly enhanced," says Zaffar Hayat, COO of Viatronix, Inc.

The non-invasiveness of the V3D procedure is itself a benefit to patients, eliminating not only the physical discomfort of a conventional colonoscopy, but also the inherent risk of the colon walls being perforated by the optical scope. Adding to that, however, is the fact that a Viatronix virtual colonoscopy requires no sedation, so patients can resume normal activities immediately after the short 15-minute procedure. Plus, there is no pre-exam fasting or harsh colon-cleansing necessary. Patients simply follow a special low-residue diet of easily digestible foods, accompanied by a pleasant-tasting drink containing a small amount of barium, two days prior to the procedure. The barium enables the system's software to electronically remove any stool remnants from the bowel images, so there is no need for enemas or vigorous laxative purging. For further information regarding Viatronix V3D-Colon, call 1-866-887-4636 or log on to http://www.viatronix.com. Dr. Perry Pickhardt may be contacted at +1-608-263-8969 or by email at [email protected].