Diagnostic value of CT-colonography as compared to colonoscopy in an asymptomatic screening population: a meta-analysis

Previous meta-analyses on CT-colonography included both average and high risk individuals, which may overestimate the diagnostic value in screening. A meta-analysis was performed to obtain the value of CT-colonography for screening. A search was performed using PubMed, Embase and Cochrane. Article selection and critical appraisal was done by two reviewers. Inclusion criteria: prospective, randomized trials or cohort studies comparing CT-colonography with colonoscopy (a parts per thousand yen50 participants), a parts per thousand yen95% average risk participants a parts per thousand yen50 years. Study characteristics and 2 x 2 contingency Tables were recorded. Sensitivity and specificity estimates were calculated per patient and per polyp (a parts per thousand yen6 mm, a parts per thousand yen10 mm), using univariate and bivariate analyses. Five of 1,021 studies identified were included, including 4,086 participants (< 1% high risk). I-2-values showed substantial heterogeneity, especially for 6-9 mm polyps and adenomas: 68.1% vs. 78.6% (sensitivity per patient). Estimated sensitivities for patients with polyps or adenomas a parts per thousand yenaEuro parts per thousand 6 mm were 75.9% and 82.9%, corresponding specificities 94.6% and 91.4%. Estimated sensitivities for patients with polyps or adenomas a parts per thousand yenaEuro parts per thousand 10 mm were 83.3% and 87.9%, corresponding specificities 98.7% and 97.6%. Estimated sensitivities per polyp for advanced adenomas a parts per thousand yenaEuro parts per thousand 6 mm and a parts per thousand yenaEuro parts per thousand 10 mm were 83.9% and 83.8%. Compared to colonoscopy, CT-colonography has a high sensitivity for adenomas a parts per thousand yenaEuro parts per thousand 10 mm. For (advanced) adenomas a parts per thousand yenaEuro parts per thousand 6 mm sensitivity is somewhat lower.