Computed Tomographic Colonography in Screening Healthy Participants for Colorectal Cancer (ACRIN 6664)

• Sensitivity [ Time Frame: 1 Day ]
  Evaluate the sensitivity of CT colonography for detecting participants with at least one proved clinically significant large lesion (at least 10 mm in diameter), using colonoscopy as the reference standard.
  
  

• Interobserver variation in accuracy [ Time Frame: 1 Day ]
  Evaluate interobserver variation in accuracy of interpreting CTC examinations, including any benefits of 1) a primary 3D read and/or 2) independent second interpretations.
  
  
• Additional secondary outcome measures [ Time Frame: 1 Day ]
  1. To develop a well-annotated database of CTC case materials for future study. Data appropriate for computed-aided diagnosis development will be collected for this purpose. This data, subject to ACRIN Image Archive policies, will be made available to the image processing and clinical community. Availability of CTC case materials may be via the internet.
  2. To assess the cost-effectiveness of CTC compared to other CRC screening tests.
  
  

• Descriptive outcomes [ Time Frame: 1 Day ]
  1. To describe the effects of different colon preparations, as ordered by the referring gastroenterologist, on accuracy of CTC.
  2. To describe patient acceptance of CT colonography and their willingness to have a repeat examination in comparison to optical colonoscopy.
  3. To describe the various morphologic features, distribution, and frequency of flat colonic lesions, and to estimate the accuracy of CTC in detecting flat lesions in the colon.
  4. To describe the prevalence and clinical significance of extracolonic abnormalities detected in the course of a CTC examination.
  5. To describe the various methods of CTC evaluation and assess differences in software platforms by evaluating user preferences and performance differences, including evaluation times.
  
  

OBJECTIVES:

Primary

• Compare the sensitivity of computed tomographic colonography (CTC) vs colonoscopy for detecting significantly large lesions (≥ 10 mm in diameter) in asymptomatic participants, in terms of specificity, area under the ROC curve, and predictive values for detecting clinically significant colorectal neoplasia.

Secondary

• Determine the interobserver variation in accuracy of interpreting CTC examinations of these participants, including any benefits of a primary 3-dimensional read and/or independent second interpretations.
• Determine the effects of different colon preparations on the accuracy of CTC in these participants.
• Compare participant acceptance and willingness to have a repeat examination by CTC vs colonoscopy.
• Determine the accuracy of CTC in detecting flat lesions in the colon of these participants.

OUTLINE: This is a multicenter study.

Participants receive an oral laxative, oral bisacodyl, and three doses of oral barium sulphate 24 hours before imaging. After cathartic cleansing, participants undergo computed tomographic colonography followed by colonoscopy.

Participants are followed up for approximately 4 weeks.

PROJECTED ACCRUAL: A total of 2,607 participants will be accrued for this study.