Virtual Colonography: On the Brink

Twitter icon
Facebook icon
LinkedIn icon
e-mail icon
Google icon

CT colonography or virtual colonoscopy is far from a new procedure. In fact, CT colonography has been around since the late 1990s. Although the procedure seems to offer some advantages over conventional optical colonoscopy, adoption has been sluggish. Colorectal cancer is the second leading cause of cancer death in the U.S., and third most common cancer among men and women in the U.S. Yet, fewer than half of patients over age 50 comply with colorectal cancer screening guidelines. Some 90 percent of colon cancers occur over age 50.

Optical colonoscopy allows both the detection and removal of polyps, but it is invasive and requires bowel preparation, sedation and minor recovery time. On the other hand, virtual colonoscopy offers a minimally invasive alternative to polyp detection. Studies indicate many patients would prefer and comply with CT colonography over optical colonoscopy. CT colonography has a markedly lower risk of perforating the colon than conventional colonoscopy. What’s more, at $600 to $1,500 per study, the cost of the high-tech procedure can be comparable or lower than conventional colonoscopy. Still, utilization for virtual colonography sits at a mere 15 percent. But times are changing, and CT colonography appears poised for a breakthrough. Specifically, CT colonography should be reimbursable in the next two years. In the meantime, the cost runs between $400 and $800 per study.

Another game-changer could be the results expected soon of the largest multicenter research study to compare the effectiveness of the two technologies, being conducted by the American College of Radiology Imaging Network (ACRIN).

Ready for prime time

When CT colonography first became a clinical option, many facilities hesitated to rush into virtual colonoscopy because the technology did not seem ready for prime time, says David Kim, MD, assistant professor of abdominal imaging at University of Wisconsin Madison Health System.

The last several years have delivered improved techniques and software enhancements to make virtual colonoscopy more practical, easier to read, effective and comparable to optical colonoscopy. On the procedure side, fluid and fecal tagging makes it easier for readers to distinguish residual stool from polyps and the switch from room air to carbon dioxide allows uniform distension of the colon for better visualization. On the technology end, the advent of primary 3D display also simplifies polyp detection and aids workflow.

Reimbursement: The next barrier

Technology adoption is a multi-faceted process. Widespread adoption requires proof of clinical utility and adequate reimbursement. Currently, the primary barrier to widespread adoption of virtual colonography is on the payment side; the Centers for Medicare and Medicaid Services (CMS) do not mandate reimbursement for virtual colonoscopy. “Third-party payors and Medicare are being careful not to prematurely approve several of the rapidly developing new screening technologies, such as CT colonography,” explains Beth McFarland, MD, chair of the American College of Radiology (ACR) Colon Cancer Committee. The organizations look for clinical validation and standardization of a procedure prior to widespread reimbursement.

Currently, physicians must use category III CPT codes for virtual colonography. These “emerging technology” codes are not assigned value, which make CT colonography nonreimbursable in most cases. (CT colonography is covered locally in some instances, mainly in the case of a failed or incomplete optical colonoscopy.) In addition, a handful of patients do pay out of pocket. 

Reimbursement, however, is not the only hitch, says Judy Yee, MD, chief of radiology at San Francisco Veterans Administration Medical Center in California. The U.S. lacks a critical mass of radiologists trained in CT colonography, says Yee.

The next 12 to 18 months will deliver significant changes. CT colonography will shift from an emerging technology to an established procedure. One of the primary factors behind the shift is the expected release of the ACRIN II Trial results early this year. “ACRIN II should have a tremendous impact towards more generalizable validation,” says McFarland. Researchers announced results at several meetings this fall and shared that the 15-center trial demonstrates the diagnostic efficacy and interobserver consistency for clinically significant polyps. Other studies supporting screening CT colonography include the Italian