A randomized controlled trial comparing high-definition white light colonoscopy to i-scan enhanced colonoscopy for adenoma detection in the right colon

Objectives: Although colonoscopy with high definition white light (HDWL) is considered the standard for colorectal cancer (CRC) screening, rates of missed lesions in the right colon appear to be high. This randomized controlled trial evaluated whether the use of i-scan increases adenoma detection rates (ADR) in the right colon among a population at increased risk for CRC. Methods: Eligible patients referred for a screening colonoscopy were randomly assigned to undergo colonoscopy using either HDWL only or i-scan enhancement (i-scan 1 or 2). The primary objective is to compare ADR in the right colon using HDWL versus i-scan. Results: A total of 439 patients were included (mean age 52, 44% male). There was no difference of ADR in the right colon between HDWL (22%) and i-scan enhancement (i-scan 1 (26%) and 2 (21%), p = 0.52). The difference in the entire colon was not also significant between the two techniques (HDWL (37%), i-scan 1 (39%) and 2 (38%), p = 0.95). A second look in the right colon significantly increased the detected number of adenomas irrespective of imaging modality (36/139 polyps (26%) missed on the first look, p = 0.04). Conclusions: i-scan did not increase ADR in the right colon compared to HDWL. A second look in the right colon is important to increase ADR regardless of imaging modality.