Background: Colorectal cancer is the global health problem and its incidence is still rising. Detection by colorectal cancer screening and removal of advanced adenomas have been shown to reduce both the incidence of cancer and cancer-related mortality. Computed tomographic (CT) colonography is a non-invasive technique, with no need for sedation, and low risk of procedure related complications. CT colonography for colorectal cancer screening is not widespreadly used in Thailand, because of the low prevalence of colorectal polyps in the screening setting and the published studies of CT colonography in average-risk individuals have not been well established in Thai populations.

Objective: To assess the accuracy of CT colonography for colorectal cancer screening and detecting colorectal polyps in asymptomatic adults at Phramongutklao hospital.

Materials and Methods: The present study was a cross-sectional study. The participants were recruited among all asymptomatic adults at Gastroenterology Unit, Department of Medicine, Phramongutklao Hospital. Frome July 2013 to November 2014, 74 participants underwent CT colonography followed by conventional colonoscopy as the reference standard on the same day. Accuracy of CT colonography was evaluated for detecting colorectal polyps of at least 10 mm in size and at least 6 mm in size.

Results: The accuracy, sensitivity and specificity of CT colonography for detection of colorectal polyps of 10 mm or larger were 100% in all aspects. CT colonography for detection of colorectal polyps of 6 mm or larger had accuracy of 97.8%, a sensitivity of 82.4%, specificity of 98.4%, positive predictive value of 66.7% and negative predictive value of 99.3%.

Conclusion: A potentially effective use of CT colonography as an alternative to conventional colonoscopy for colorectal cancer screening and detecting colorectal polyps in asymptomatic adults.

Keywords: Colorectal cancer, CT colonography, Accuracy, Phramongkutklao Hospital