[A prospective comparison of video colonoscopy and CT colonography in asymptomatic patients screened for colorectal cancer].

BACKGROUND AND OBJECTIVE It was the aim of this study to compare the sensitivity and specificity of low-dose CT colonography (CTC) with that of optical colonoscopy (OC) in asymptomatic patients undergoing these tests in a screening program for colonic cancer. PATIENTS AND METHODS 58 patients (mean age 62.6 years) were included. They underwent low dose CTC and, immediately afterwards, colonoscopy. The colonoscopists were unaware of the CTC findings. A "second look" was performed if a lesion seen in CTC had been missed in the first colonoscopy. RESULTS A total of 150 lesions were detected and histologically confirmed. 136 were found to be polypoid lesions, classified as either hyperplastic polyps (n = 66) or polyps with intraepithelial neoplasia (n = 70). In the per-patient analysis only 22.4 % of patients had no polypoid lesion, 27.6 % had at least one hyperplastic and 50.0 % had at least one adenomatous lesion. Sensitivity for adenomas of all size categories was calculated 55.7 % for CTC and 92.9 % for OC. This marked difference (both for the detection of individual lesions and the per-patient analyses) does not reach significance in the two-sided McNemar test. CONCLUSIONS There was a high prevalence of lesions with intraepithelial neoplasia in this screening group. OC had a higher sensitivity than CTC in the detection of lesions smaller than 10 mm.