Brief Article
Copyright ©2012 Baishideng Publishing Group Co., Limited. All rights reserved.
World J Gastroenterol. Nov 7, 2012; 18(41): 5905-5911
Published online Nov 7, 2012. doi: 10.3748/wjg.v18.i41.5905
Comparative effectiveness of i-SCAN™ and high-definition white light characterizing small colonic polyps
Johanna L Chan, Li Lin, Michael Feiler, Andrew I Wolf, Diana M Cardona, Ziad F Gellad
Johanna L Chan, Michael Feiler, Andrew I Wolf, Ziad F Gellad, Department of Medicine, Duke University Medical Center, Durham, NC 27705, United States
Li Lin, Ziad F Gellad, Duke Clinical Research Institute, Durham, NC 27705, United States
Diana M Cardona, Department of Pathology, Duke University Medical Center, Durham, NC 27705, United States
Ziad F Gellad, Durham VA Medical Center, Durham, NC 27705, United States
Author contributions: Chan JL, Feiler M, Wolf AI, Cardona DM, and Gellad ZF contributed to study conception and design, analysis, and data interpretation; Gellad ZF, Chan JL and Lin L analyzed and interpreted data; Chan JL, Lin L, and Gellad ZF drafted the article; and all authors contributed to critical revision and final approval of the article.
Supported by An Unrestricted Educational Grant from PENTAX Medical Company; A Career Development Research Award from the American Society for Gastrointestinal Endoscopy, to Dr. Gellad
Correspondence to: Ziad F Gellad, MD, MPH, Department of Medicine, Duke University Medical Center, Box 3913, Durham, NC 27710, United States. ziad.gellad@duke.edu
Telephone: +1-919-6687067 Fax: +1-919-6687124
Received: April 16, 2012
Revised: June 13, 2012
Accepted: June 28, 2012
Published online: November 7, 2012
Abstract

AIM: To evaluate accuracy of in vivo diagnosis of adenomatous vs non-adenomatous polyps using i-SCAN digital chromoendoscopy compared with high-definition white light.

METHODS: This is a single-center comparative effectiveness pilot study. Polyps (n = 103) from 75 average-risk adult outpatients undergoing screening or surveillance colonoscopy between December 1, 2010 and April 1, 2011 were evaluated by two participating endoscopists in an academic outpatient endoscopy center. Polyps were evaluated both with high-definition white light and with i-SCAN to make an in vivo prediction of adenomatous vs non-adenomatous pathology. We determined diagnostic characteristics of i-SCAN and high-definition white light, including sensitivity, specificity, and accuracy, with regards to identifying adenomatous vs non-adenomatous polyps. Histopathologic diagnosis was the gold standard comparison.

RESULTS: One hundred and three small polyps, detected from forty-three patients, were included in the analysis. The average size of the polyps evaluated in the analysis was 3.7 mm (SD 1.3 mm, range 2 mm to 8 mm). Formal histopathology revealed that 54/103 (52.4%) were adenomas, 26/103 (25.2%) were hyperplastic, and 23/103 (22.3%) were other diagnoses include “lymphoid aggregates”, “non-specific colitis,” and “no pathologic diagnosis.” Overall, the combined accuracy of endoscopists for predicting adenomas was identical between i-SCAN (71.8%, 95%CI: 62.1%-80.3%) and high-definition white light (71.8%, 95%CI: 62.1%-80.3%). However, the accuracy of each endoscopist differed substantially, where endoscopist A demonstrated 63.0% overall accuracy (95%CI: 50.9%-74.0%) as compared with endoscopist B demonstrating 93.3% overall accuracy (95%CI: 77.9%-99.2%), irrespective of imaging modality. Neither endoscopist demonstrated a significant learning effect with i-SCAN during the study. Though endoscopist A increased accuracy using i-SCAN from 59% (95%CI: 42.1%-74.4%) in the first half to 67.6% (95%CI: 49.5%-82.6%) in the second half, and endoscopist B decreased accuracy using i-SCAN from 100% (95%CI: 80.5%-100.0%) in the first half to 84.6% (95%CI: 54.6%-98.1%) in the second half, neither of these differences were statistically significant.

CONCLUSION: i-SCAN and high-definition white light had similar efficacy predicting polyp histology. Endoscopist training likely plays a critical role in diagnostic test characteristics and deserves further study.

Keywords: Colonoscopy; Adenoma; Virtual chromoendoscopy; Colonic polyps; Comparative effectiveness