The CMS decision to retain nonapproval status for CT colonography (CTC) as a screening method for Medicare patients was a bitter pill for radiology to swallow—all the more bitter because, prior to the February 11 decision, the mood had been optimistic. After years of battling on behalf of CTC, researchers and CTC advocates seemed finally to have turned a corner that would result in CMS approval.
Bibb Allen, Jr, MD
In a 2007 study, Kim et al¹ used a mathematical model to evaluate the cost effectiveness of CTC compared with optical colonoscopy (OC) and flexible sigmoidoscopy. In this study, with no threshold for polyp size, CTC was found least expensive of the screening methods, with a cost of $7,138 per life-year gained, compared with $7,407 for sigmoidoscopy and $9,180 for OC. With a polyp threshold of 6 mm, CTC was even more cost effective, at $4,361 per life-year gained.
Then, in September 2008, the ACR released results of its long anticipated ACR Imaging Network (ACRIN) trial² comparing CTC with OC. The results showed CTC to have sensitivity rates of 90% and specificity rates of 86% for precancerous polyps 10 mm or larger. These rates were comparable with OC, the report says. Even before the ACRIN results were officially released, however, the American Cancer Society (ACS) gave CTC a huge boost by approving it as a screening option for colorectal cancer. To some, the ACS validation, in March 2008, seemed to signal that CMS would approve CTC for screening Medicare patients.
Bibb Allen, Jr, MD, chair of the ACR's Commission on Economics, told ImagingBiz.com last summer, "We don't know exactly how [CMS] will respond. We are optimistic for a favorable decision."
A favorable CMS ruling, however, was not to be. In the announcement last month, CMS officials wrote, "The evidence is inadequate to conclude that CT colonography is an appropriate colorectal cancer screening test. CT colonography for colorectal cancer screening remains uncovered." The agency then called for additional comment over the next 30 days, leaving the door open for a reversal of its decision—but a reversal seemed unlikely, because the agency added that if a reversal occurred, CMS would then have to determine the cost effectiveness of CTC. In the week before the comment period ended on March 13, colorectal screening experts traveled to Capitol Hill to recommend the agency change its decision, stressing that seniors should have access to the minimally invasive screening test.
To buttress its decision, CMS cited a series of votes by its Medical Evidence Development & Coverage Advisory Committee taken at a meeting on November 19, 2008. The committee members voted on seven key questions on CTC, including effectiveness, cost, and the likelihood of wider screening following CTC approval. Overall, the panel gave lukewarm scores to CTC. Some responses, the CMS report noted, "amounted to a vote of no confidence" in the procedure.
In a series of review findings, CMS argued that CTC may be less effective than OC for polyps smaller than 10 mm. It also noted the issue of radiation exposure and questioned the expertise of radiologists in community settings who might be overseeing and interpreting the scans. The impact of extracolonic findings spotted by radiologists while performing CTC was also raised as an issue. Such findings occur often during CTC screening. One study, performed at Wake Forest University in 2006³, found that extracolonic findings such as lung nodules and kidney lesions (which are subject to independent workups) added an average of $231 to the cost of a CTC scan. If CMS approved CTC for screening, it would presumably pay for testing the extracolonic abnormalities for disease as well.
Judy Yee, MD, is chief of radiology at the San Francisco VA Medical Center and is also professor and vice chair of the department of radiology and biomedical imaging at the University of California–San Francisco (UCSF). She has been a pioneer of CTC through studies at the VA and elsewhere. She has also developed national guidelines for performing CTC screening, and she teaches CTC at the UCSF medical school.
"Currently, less than 40% of those who should be screened are actually getting screened," Yee says. "This is with the options of colonoscopy, barium enema, or flexible sigmoidoscopy." Most people continue to rely on a routine physician’s-office test, the fecal occult blood test (FOBT), but the FOBT will only detect bleeding cancers; it won't detect