When the Centers for Medicare and Medicaid Services decided to deny coverage (and therefore, payment) for computed tomography colonography (CTC) in February, it set off a firestorm of debate among imaging advocates, providers, payers, and consumers.
Traditional colonoscopy has been the gold standard to screen for colon cancer. It can be uncomfortable or inconvenient.
CTC, sometimes called virtual colonoscopy, is less invasive compared to traditional colonoscopy, does not require sedation, and is more convenient.
Assessing the evidence
Is virtual colonoscopy as effective as the traditional screening? CMS says “the evidence is inadequate” and CTC will not be covered. A final decision is scheduled for May, but had not been made at press time.
Linda Yee, MD, professor of radiology at the University of California–San Francisco, disagrees with CMS’s decision. “We have numerous screening tools that are covered, yet less than 40 percent of the American public comes in for any kind of colon cancer screening.”
And a screening test that is more convenient and less invasive is more likely to appeal to people.
National coverage needed
Yee says that every state has local coverage decisions. “Local payers will pay for virtual colonoscopy if it’s considered diagnostic,” she says. “What’s needed, however, is national screening coverage.”
Medical directors need to be aware that not enough screening is being performed on the target population, which “is a shame because this malignancy can be prevented. CTC has been proven to be as effective as colonoscopy and we should fight for reimbursement for screening,” says Yee.
Summary of findings of comparative value
The Washington State Health Care Authority conducted a health technology assessment on computed tomography colonography.
CTC vs. no screening
CTC vs. colonoscopy
The following numbers compare no screening to a strategy of screening with CTC every five years and referring for colonoscopy all lesions ≥ 6mm.
Cost of CTC
CTC cost to prevent one case of cancer vs. no screening
CTC cost to prevent one death vs. no screening
CTC cost per life-year gained vs. no screening
In direct comparison to colonoscopy, CTC every 10 years is more expensive and marginally less effective in preventing cases of cancer (47 vs. 52 in a lifetime cohort of 1,000 individuals) and cancer deaths (24 vs. 26). Only one CTC screening strategy is more effective than colonoscopy every 10 years, and that strategy is to perform CTC every five years with colonoscopy referral for polyps ≥ 6mm. For this strategy the cost-effectiveness is:
Cost of CTC
Cost of colonoscopy
The cost per life-year gained for CTC vs. colonoscopy
Source: Washington Health State Health Care Authority. Health Technology Assessment. Computed Tomography Colonography. Feb. 1, 2008.