Medicare Coverage of CTC Enhances Colorectal Cancer Screening Options

In conjunction with the RadioGraphics monograph, updates are provided on the evolving role of medical imaging in disease screening.

Screening CT colonography (CTC) has seen limited utilization despite generating significant interest since the early 2000s. This limitation is attributed largely to a non-coverage decision by the Centers for Medicare & Medicaid Services (CMS) in 2009 and an initial lack of an 'A grade' recommendation from the U.S. Preventive Services Task Force (USPSTF). However, this landscape shifted in January 2025 when Medicare began covering screening CTC, while the USPSTF had already included the exam for average-risk adults aged 50-75 since 2016, with a recent update lowering the screening initiation age to 45.

Dr. Michio Taya, an assistant professor of radiology at the University of Wisconsin School of Medicine and Public Health, emphasized that the 2009 CMS decision posed both material and symbolic barriers to CTC adoption. He noted that extensive research over two decades has demonstrated that CTC is comparable to traditional colonoscopy in terms of sensitivity and safety.

Colorectal cancer now stands as the leading cause of cancer deaths among adults younger than 50, yet screening rates in adults aged 45 and older remain at only 59%. Since 2010, CTC's utilization rates among adults aged 50-75 have fluctuated between 1.3% and 2.1%. Dr. Taya remarked that there is a prevailing belief among many primary care physicians that CTC remains investigational and not fully validated.

The strategy of selective polypectomy and surveillance with CTC is supported by long-term data suggesting stability or regression of most diminutive polyps, accompanied by a minimal cancer risk.

A study published in the 2007 New England Journal of Medicine by Kim et al. highlighted that the yield of advanced neoplasia from CTC's selective polypectomy strategy was comparable to colonoscopy. It found that while colonoscopy led to four-fold more polypectomies, it also incurred complications, such as seven perforations, which did not occur with CTC.

Dr. Taya pointed out that CTC avoids unnecessary removal of benign polyps, thus minimizing risks associated with colonoscopic procedures. He stressed that the main objective with CTC is to detect precancerous lesions early to prevent cancer development completely.

With Medicare's coverage, historic barriers to CTC screening are diminishing. Although reimbursement varies by payer and region, CTC is considered a more cost-effective option than colonoscopy, being less invasive. National training initiatives are making CTC interpretation more accessible to radiologists, who achieve competence after interpreting about 164 exams.

Dr. Taya noted the need for outreach to primary care physicians, who often determine patients' screening choices. He referenced that patients opting for stool-based tests must be open to potential follow-ups with colonoscopy, reinforcing the importance of considering CTC as a viable first-line screening option.

To further boost CTC referrals, Dr. Taya urged that information about its safety and effectiveness needs to reach primary care providers. In a USPSTF systematic review encompassing 89,073 patients, no significant complications were found for screening CTC, while screening colonoscopy had a reported 14.6 serious bleeds and 3.1 perforations per 10,000 procedures.

Dr. Taya concludes by encouraging radiologists to correct the misconception that CTC is investigational, advocating for its validated role in colorectal cancer screening and its potential impact on patient outcomes.