Description
Computed tomographic colonography (CTC), also referred to as virtual colonoscopy, is a minimally invasive structural examination of the colon and rectum and can be used as a screening tool to evaluate for colorectal polyps or neoplasms in the asymptomatic patient.

Policy
Computer tomographic colonography (CTC) is considered medically appropriate as an alternative to colonoscopy for screening asymptomatic individuals in the following two 
situations:

1. Asymptomatic Individuals at Average Risk for colorectal cancer (CRC)
   • Every 5 years starting at age 45
     • Average risk includes:
       • No personal history of any of the following:
         • Adenoma or serrated sessile polyp/lesion (SSP/SSL)
         • Colorectal cancer
         • Inflammatory bowel disease (IBD)
         • Known hereditary CRC syndrome
         • Cystic Fibrosis
         • Childhood cancer
       • AND
         • No family history of any of the following:
           • Advanced adenoma or serrated sessile polyp/lesion (SSP/SSL) in a first degree relative
           • Colorectal cancer
     • NOTE: Any one of the above personal or family history risk factors places the patient at increased risk for colorectal cancer and screening is with colonoscopy rather than CTC unless a contraindication to colonoscopy is provided
     • NOTE: Generally screening for colorectal cancer stops at age 75, however, it is reasonable to continue screening above age 75 if the patient’s life expectancy is ≥ 10 years
2. Patients at Increased Risk (one or more risk factors above) for colorectal cancer:
   • As an alternative to colonoscopy in individuals at increased risk for colorectal cancer AND a contraindication to colonoscopy has been provided:
     • Contraindications to colonoscopy include known obstructing colonic lesion, anatomic abnormality preventing passage of the scope, technical difficulty, patient is unable to undergo sedation or has medical conditions such as recent myocardial infarction, recent colonic surgery, a bleeding disorder, or severe lung and/or heart disease OR
     • A relative contraindication to colonoscopy such as symptomatic acute colitis, acute diarrhea, recent acute diverticulitis, recent colorectal surgery, symptomatic colon-containing abdominal wall hernia, small bowel obstruction.

NOTE: If a polyp 6-9 mm is detected at screening CTC and polypectomy is not done, then the follow-up CTC is considered diagnostic rather than screening.

Rationale/Background
Contraindications and Preferred Studies

• Contraindications and reasons why a CT/CTA cannot be performed may include: impaired renal function, significant allergy to IV contrast, and pregnancy (depending on trimester).
• Contraindications and reasons why an MRI/MRA cannot be performed may include: impaired renal function, claustrophobia, non-MRI compatible devices (such as non-compatible defibrillator or pacemaker), metallic fragments in a high-risk location, patient exceeds weight limit/dimensions of MRI machine.

SUMMARY OF EVIDENCE
ACR-SABI-SAR Practice Parameter for the Performance of Computed Tomography (CT) Colonography in Adults ⁽³⁾

• Study Design: This document outlines the practice parameters for the performance of CT colonography in adults. It includes guidelines for screening, surveillance, and diagnostic examinations.
• Target Population: The target population includes adults at average or moderate risk for developing colorectal carcinoma. This includes individuals with a preceding positive stool-based test or positive family history.

Key Factors:

• Indications: CT colonography is indicated for screening individuals at average or moderate risk, surveillance of patients with a history of colonic neoplasm, and diagnostic examination in symptomatic patients.
• Contraindications: Conditions requiring caution include symptomatic acute colitis, recent colorectal surgery, and known or suspected colonic perforation 1.
• Preparation: Colon preparation involves a combination of cleansing laxatives, tagging agents, and iodinated contrast material.
• Technique: The examination technique includes mechanical insufflation using carbon dioxide, imaging in multiple positions, and use of low-dose, non-enhanced CT techniques.
• Quality Control: Quality control measures include ensuring complete anatomic coverage of the colon and rectum, adequate colon cleansing and distention, and tracking radiation dose.

Screening for Colorectal Cancer: US Preventive Services Task Force Recommendation Statement⁽²⁾

• Study Design: This document provides the US Preventive Services Task Force (USPSTF) recommendation statement on screening for colorectal cancer. It includes a systematic review of the benefits and harms of screening strategies. 
• Target Population: The target population includes asymptomatic adults aged 45 years or older at average risk of colorectal cancer.

Key Factors:

• Screening Tests: The recommended screening tests include stool-based tests (high-sensitivity guaiac fecal occult blood test, fecal immunochemical test, stool DNA test) and direct visualization tests (colonoscopy, CT colonography, flexible sigmoidoscopy).
• Benefits: Screening for colorectal cancer in adults aged 50 to 75 years has substantial net benefit, while screening in adults aged 45 to 49 years has moderate net benefit.
• Harms: The harms of screening include bleeding and perforation from colonoscopy, and potential evaluation and treatment of incidental extracolonic findings from CT colonography.
• Screening Intervals: Recommended intervals for CT colonography are every 5 years

ANALYSIS OF EVIDENCE
Shared Conclusions ^(2,3)
Both documents emphasize the importance of CT colonography in colorectal cancer screening, particularly for individuals at average or moderate risk. They agree that CT colonography is a valuable tool for detecting colorectal neoplasia and improving patient outcomes.

Summary ^(2,3)
In summary, both documents provide comprehensive evidence for the use of CT colonography in colorectal cancer screening, highlighting its importance in detecting colorectal neoplasia and improving patient outcomes. The ACR practice parameters focus on the technical aspects of the procedure, while the USPSTF recommendation statement offers a broader evaluation of screening strategies and their benefits and harms.

References

1. American Cancer Society Guideline for Colorectal Cancer Screening. American Cancer Society. January 29, 2024. Accessed April 6, 2025. https://www.cancer.org/cancer/types/colon-rectal-cancer/detection-diagnosis-staging/acs-recommendations.html
2. Davidson KW, Barry MJ, Mangione CM, et al. Screening for Colorectal Cancer: US Preventive Services Task Force Recommendation Statement. JAMA. 2021;325(19):1965. doi:10.1001/jama.2021.6238
3. American College of Radiology, Society for Advanced Body Imaging, Society for Abdominal Radiology. ACR-SABI-SAR PRACTICE PARAMETER FOR THE PERFORMANCE OF COMPUTED TOMOGRAPHY (CT) COLONOGRAPHY IN ADULTS.; 2024.
4. Referenced with permission from the National Comprehensive Cancer Network Clinical Practice Guidelines in Oncology (NCCN Guidelines®) for Colorectal Cancer Screening Version 1.2024 © National Comprehensive Cancer Network, Inc. 2025. All rights reserved. To view the most recent and complete version of the guideline, go online to NCCN.org.
5. Rhode Island General Laws. The Maryellen Goodwin Colorectal Cancer Screening Act. RI Gen L 27-18-58; 2021. Accessed February 16, 2025. https://law.justia.com/codes/rhode-island/title-27/chapter-27-18/section-27-18-58/

Coding Section

Procedure and diagnosis codes on Medical Policy documents are included only as a general reference tool for each Policy. They may not be all-inclusive.

This medical policy was developed through consideration of peer-reviewed medical literature generally recognized by the relevant medical community, U.S. FDA approval status, nationally accepted standards of medical practice and accepted standards of medical practice in this community, and other nonaffiliated technology evaluation centers, reference to federal regulations, other plan medical policies and accredited national guidelines.

"Current Procedural Terminology © American Medical Association. All Rights Reserved" 

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