ACR Bulletin

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CTC, Finally

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CMS takes a big step forward to give Medicare patients access to safe, non-invasive colon screening.

We submitted our comments last month and are optimistic that the proposed coverage will be finalized in November — and take effect in January 2025.

—Katie Keysor, ACR senior director of economic policy
October 01, 2024

This past summer, after years of advocacy by the ACR and others, CMS proposed coverage of CT colonography (CTC) for colorectal cancer screening of Medicare patients in its 2025 Hospital Outpatient Prospective Payment System (HOPPS) proposed rule and its 2025 Medicare Physician Fee Schedule (MPFS) proposed rule. The ACR applauded the move as a big step forward in providing Medicare patients access to a minimally invasive colon screening exam that does not require anesthesia and can detect pre-cancerous polyps.

“These are interesting times for colorectal screening, and the proposal from CMS is very encouraging,” says Kevin J. Chang, MD, FACR, FSAR, section chief of abdominal imaging and director of MRI at Boston Medical Center. “Even after the Affordable Care Act mandated that private payers cover CTC alongside other available screening tests, it was a bit of a paradox to enforce this for private payers and not cover Medicare patients. Now CMS is leveling the playing field for patients over 65.” 

“All the noncolonoscopy screening tests are triage tests for colonoscopy,” Chang says. “I’m not arguing that colonoscopy needs to be replaced. CTC is just another triage test where, if it is positive, you go on to colonoscopy.” To emphasize that point, Chang says, radiologists have moved away from calling it a “virtual colonoscopy,” which may suggest the age-old screening procedure of colonoscopy is no longer necessary. “The idea here is that CTC is the best of the other non-invasive screening tests,” he adds. The sensitivity and specificity of CTC is higher than other tests (of stool and blood, for example).

The Time for CTC is Now

CTC was developed in the mid-1990s and approved by the U.S. Food and Drug Administration for colorectal cancer screening in 2006. Patient preparation for the study typically includes using a bowel cathartic. Following ingestion of oral contrast, insufflation of gas via the rectum and CT of the abdomen, specialized computer software reconstructs the images to create a two- or three-dimensional image of the colon

“CTC is more of a diagnostic test versus a therapeutic colonoscopy where you are chasing after a known finding,” Chang says. “Other screening tests are only optimized to pick up evidence of cancer. Stool and blood tests are picking up either DNA or immunochemical signs that something that has moved along the spectrum of cancer.” Those tests are insensitive in detecting precancerous polyps because a polyp is not yet a cancer — so many tests are false negatives and not every positive test is going to yield a polypectomy or a cancer diagnosis, Chang says.

“I believe many patients who get CTC will get a negative test result and avoid a colonoscopy,” Chang says. “We have been doing CTC for a long time, and we know the percentage of CTCs that require a follow-up colonoscopy is relatively low. So, I tell people, sure, a positive CTC is going to end up being a colonoscopy anyway — but you can roll the dice and 90% of the time you may avoid needing a colonoscopy.” 

Awareness and CTC Education are Critical

Colon screening needs to be higher up on the list of tests people are aware of and follow through on, Chang says. “It’s not as sexy as breast screening, which gets more than its fair share of media attention. The ACR does an excellent job at getting the word out, but we don’t have the same marketing budget as the companies selling home testing kits,” he notes.

These are interesting times for colorectal screening, and the proposal from CMS is very encouraging.

—Kevin J. Chang, MD, FACR, FSAR

Radiologists should be aware of tools already available to help navigate and utilize CTC. For more than a decade, the ACR’s CTC Registry has provided evidence-based health outcomes and data for decision-making — allowing facilities to compare their results regionally and nationally. Data collected in the registry is used in part to evaluate CTC as an alternative to colonoscopy. Participating facilities and physicians can review reports based on aggregated data to bolster patient safety and boost quality improvement efforts.

“It seems like getting radiologists to do lung screening has been much easier than getting them interested in CTC, because lung screening is just a low-dose noncontrast chest CT and is not hard or time-consuming to read,” Chang says. But colon screening is still important to reduce the numbers of cancer deaths, he adds. “It impacts both sexes, not just women or men like most breast and prostate cancers. In fact, of all cancer killers, if you exclude skin cancers and include men and women combined, colon cancer is the number two killer. In fact, for men under 50, it has just become number one.

There is also a disturbing increase in the number of early onset colon cancers. Colon cancers are increasingly developing in patients under the recommended screening age. This increase is the reason behind the decrease in the recommended screening age to 45 from 50 — and even 45 may not end up being early enough, he says. “There are many factors associated with the higher trend, but the fact remains that younger and younger patients are getting colon cancer,” Chang says.

“Spreading the word about potentially lifesaving colon cancer screening is something I am passionate about,” says Judy Yee, MD, FACR, chair of the ACR Colon Cancer Committee, and professor and chair of the department of radiology at Montefiore Medical Center, Albert Einstein College of Medicine. “We still see cases of colorectal cancer today that could have been prevented if the patient had undergone screening.” 

“Colorectal cancer is different from other types of malignancies in that we know the precursor polyp. It is simply a matter of getting people in to get screened,” Yee says. “It is a devastating and costly malignancy. Providing an accurate, safe and effective way to screen that is non-invasive is more appealing to certain patient cohorts — including younger patients and those in underserved areas of the country.”

Time to Train Up on CTC

Patients are only being given a binary choice between colonoscopy and FIT for non-invasive testing in many places, Chang says, and when primary care doctors recommend a colonoscopy, there are often long wait times to schedule and go in for the procedure. “There is now insufficient capacity for colonoscopy in many locations. I see colonoscopies being scheduled up to one year out. If your only alternative is a FIT (stool) test, which is nowhere near as good as a structural test like a colonoscopy or CTC, precancerous polyps can remain undetected.” The best way to prevent colon cancer is to identify pre-cancerous polyps early, he says.

“Any test is better than no test at all,” Chang says. “But when CMS finally approves CTC for Medicare patients, I think it will clear up a lot of confusion among primary care providers about whether they should be offering it as an option.” Because the payer landscape can be confusing, providers often don’t know if a payer is going to cover CTC. “Some providers don’t mention it as an option, some don’t know it’s an option, and others may not want to go through the whole preauthorization process to figure it out,” he says. “There has been so much confusion around CTC coverage that primary providers may not bring it up because it just adds to the quagmire.”

In the current workforce climate, time is a big commodity for healthcare professionals. With staffing and high-volume challenges facing radiology, it can be difficult to get radiologists on board, Chang says. “CT colonography is not typically a money maker,” Chang says. “If anything, many practices consider it a money sink, as many consider the time and effort put into performing the study may not be worth the reimbursement.” Reimbursement for Medicare patients is the next hurdle. After that, the heavy lift in radiology is getting radiologists to read the exams, Chang says. “I see many radiologists uninterested in reading CT colonography, even those with experience reading it. And I have seen many former readers stop doing it because they say it is too time-consuming.” 

Presuming that CT colonography will be covered for Medicare patients, ACR’s members should know that there may be a big uptick in interest for getting radiologists trained up on CTC, Chang says. “The ACR and SAR offer courses to read CTC — and they probably remain the best options for training up to read CTC,” he says. 

3D vendors too need to ramp up their development of offerings that are integral to the exam. “They haven’t been doing much lately in terms of CTC research and development” he says. “There is a lot more vendors could be doing to make it quicker and easier to read CTC.” There are better 3D reconstruction and new AI algorithms out there now that could be applied, for instance, he says.

The ACR’s Take on Proposed Coverage

After so many years of advocating for CTC coverage for Medicare patients, the College is rightfully encouraged with its progress. “This has been 15 years in the making, and we’re thrilled with the CMS proposal,” says Katie Keysor, ACR senior director of economic policy. “We submitted our comments last month and are optimistic that the proposed coverage will be finalized in November — and take effect in January 2025.”

But the proposed coverage comes with a slight catch. “The reimbursement rates are not very good, but the MPFS RVUs are actually quite good,” she says. The Deficit Reduction Act of 2005 requires the in-office payment rate to be paid at the lesser of the MPFS or the HOPPS rate. The HOPPS rate is significantly lower than the fee schedule rate, so that means reimbursement is going to be capped at the hospital outpatient rate, Keysor says.

“One thing we’ve asked for in our comment letter is that if a follow-up colonoscopy is required after a CT colonography, it be covered 100% without patient cost sharing,” Keysor says. “If other tests (blood and stool) available to patients come back positive and they need a colonoscopy, CMS is proposing 100% coverage.”

The ACR appreciates the opportunity to provide comments on the CY 2025 PFS proposed rule, Keysor says. The College is urging CMS to continue to work with physicians and their professional societies through the rulemaking process to create a stable and equitable payment system and to promote an equitable delivery system.

“We are hopeful that CMS will help us move the needle on this serious problem by approving CTC for Medicare patients, as it has for privately insured individuals,” Yee says. “The science is there for CTC, and it really doesn’t make sense not to cover it.”


For more information on the CMS coverage proposal or ACR’s comments to CMS, contact Katie Keysor, ACR senior director of economic policy. If you have questions or comments about this article, contact Chad Hudnall. Don’t forget to follow the Bulletin on X (@ACRBulletin) for recent updates on patient screening and the latest news and analysis of the most pressing issues driving the specialty.


Colon Screening Tools for Radiologists and Patients

ACR has compiled a host of resources for radiologists who perform CT colonography, including patient-friendly information on the CTC exam and private payer coverage. You will also find links to more information on the ACR Appropriateness Criteria®, Practice Parameters and Technical Standards, the CTC Registry and C-RADS®, which provides a standard reporting approach for colorectal findings in patients.

In Focus: Colon Cancer Awareness

In Focus content packages are designed to highlight defining topics in radiology today. The curated packages offer a spectrum of case studies, podcasts and related content with actionable steps providers can follow to begin or enhance efforts in their own practices. This Colon Cancer Awareness In Focus, shares resources that can help foster discussions with patients about their options.

ACR My CTC Locator

In addition to encouraging patients and referring providers to discuss all available screening options, ensure your facility is registered in the ACR My CT Colonography locator tool. Patients and referring providers can use this tool to locate the nearest CTC screening facility.


Related Readings from the Bulletin

Author Chad Hudnall  senior writer, ACR Press