CT colonography papers flood the gates at McCormick Place

Rather than retreating after the hard blow handed them by the Centers for Medicare and Medicaid Services, which refused to grant reimbursement for the application in May, CT colonography researchers will arrive at the 2009 RSNA meeting with more of what CMS wants: hard data.

CMS' decision intensified the debate on CTC's worth for colorectal cancer screening and whether it should be accepted in routine practice. When it came to CTC's alleged weaknesses, the government cited a lack of conclusive data on benefits and harms to back its policy.

Since then, however, the evidence that CTC is a screening procedure just as good as or better than colonoscopy has continued to pile up, said Dr. Benjamin M. Yeh, chair of the RSNA's scientific gastrointestinal radiology subcommittee.

"CT colonography could be complementary—and even superior in many ways—to regular colonoscopy," Yeh said in an interview with Diagnostic Imaging.

Several papers address CTC performance in direct comparison with colonoscopy on large patient populations, including new data from participants in the American College of Radiology Network National CT Colonography Trial. Parameters explored include patient acceptance and tolerance; the use of new agents for fecal tagging; the effectiveness of radiation dose reduction protocols, and sensitivity for detection of nonpolypoid colorectal adenomas.

A number of papers include the assessment of multiple 2D and 3D postprocessing techniques. And an entire session Nov. 30 will be devoted to the use of computer-aided detection for the early diagnosis of colorectal lesions.

Researchers have spent serious time addressing CTC's strengths. But this time around they have also focused on CTC's potential weaknesses, including radiation exposure and the economic and emotional impact of extracolonic findings, said Yeh, an associate professor of radiology at the University of California, San Francisco.

Some of the questions explored by these papers address whether too many extracolonic findings lead to a detriment to patients and healthcare because of the additional workup, Yeh said. Physicians have to carefully weigh not only CTC findings, but the potential detection, for example, of abdominal aortic aneurysms or cancers.

"There is more data coming out in that respect," he said.