Endoscopy corner
Clinical Evaluation of Endoscopic Trimodal Imaging for the Detection and Differentiation of Colonic Polyps

https://doi.org/10.1016/j.cgh.2008.10.025Get rights and content

Background & Aims

Endoscopic trimodal imaging (ETMI) incorporates high-resolution endoscopy (HRE) and autofluorescence imaging (AFI) for adenoma detection, and narrow-band imaging (NBI) for differentiation of adenomas from nonneoplastic polyps. The aim of this study was to compare AFI with HRE for adenoma detection and to assess the diagnostic accuracy of NBI for differentiation of polyps. This was a randomized trial of tandem colonoscopies. The study was performed at the Academic Medical Center in Amsterdam.

Methods

One hundred patients underwent colonoscopy with ETMI. Each colonic segment was examined twice for polyps, once with HRE and once with AFI, in random order per patient. All detected polyps were assessed with NBI for pit pattern and with AFI for color, and subsequently removed. Histopathology served as the gold standard for diagnosis. The main outcome measures of this study were adenoma miss-rates of AFI and HRE, and diagnostic accuracy of NBI and AFI for differentiating adenomas from nonneoplastic polyps.

Results

Among 50 patients examined with AFI first, 32 adenomas were detected initially. Subsequent inspection with HRE identified 8 additional adenomas. Among 50 patients examined with HRE first, 35 adenomas were detected initially. Successive AFI yielded 14 additional adenomas. The adenoma miss-rates of AFI and HRE therefore were 20% and 29%, respectively (P = .351). The sensitivity, specificity, and overall accuracy of NBI for differentiation were 90%, 70%, and 79%, respectively; corresponding figures for AFI were 99%, 35%, and 63%, respectively.

Conclusions

The overall adenoma miss-rate was 25%; AFI did not significantly reduce the adenoma miss-rate compared with HRE. Both NBI and AFI had a disappointing diagnostic accuracy for polyp differentiation, although AFI had a high sensitivity.

Section snippets

Patients

Patients scheduled for colonoscopy in the Academic Medical Center in Amsterdam were screened for participation. Inclusion criteria were a personal history of adenomas or CRC, or a positive family history for CRC (one first-degree family member fulfilling one of the revised Bethesda criteria).38 Exclusion criteria were age younger than 18 years, polyposis syndromes, inflammatory bowel disease, severe coagulopathy, and insufficient bowel preparation. Eligible patients were invited for this study

Patient Characteristics

Between June 2005 and March 2007 a total of 109 patients gave informed consent; 6 patients were excluded because of poor bowel preparation and 3 patients were excluded because of a technically difficult and painful colonoscopy (Figure 3). The mean age of the remaining 100 patients (43 male) was 52 years (±14 y) and the cecal intubation rate was 100%. Fifty patients underwent tandem colonoscopy with a first inspection in the AFI mode; the remaining 50 patients were examined with HRE first. No

Discussion

Because adenoma miss-rates may cause interval cancers in patients undergoing periodic colonoscopy, great efforts are being made to reduce miss-rates by good quality colonoscopy and advanced imaging techniques.8 Chromoendoscopy has been shown to improve both the detection and differentiation of colonic polyps.15, 16, 17, 18, 19, 20 However, advanced imaging techniques such as AFI and NBI are easier to use and may be more cost effective because they involve only a push on a button instead of the

Acknowledgements

Trial registration is as follows: Trialregister.nl, identifier: ISRCTN76121851.

References (60)

  • M.A. Kara et al.

    Endoscopic video autofluorescence imaging may improve the detection of early neoplasia in patients with Barrett's esophagus

    Gastrointest Endosc

    (2005)
  • M.A. Kara et al.

    Endoscopic video-autofluorescence imaging followed by narrow band imaging for detecting early neoplasia in Barrett's esophagus

    Gastrointest Endosc

    (2006)
  • T. Lecomte et al.

    Chromoendoscopic colonoscopy for detecting preneoplastic lesions in hereditary nonpolyposis colorectal cancer syndrome

    Clin Gastroenterol Hepatol

    (2005)
  • D.K. Rex et al.

    Quality in the technical performance of colonoscopy and the continuous quality improvement process for colonoscopy: recommendations of the U.S. Multi-Society Task Force on Colorectal Cancer

    Am J Gastroenterol

    (2002)
  • M. Hirata et al.

    Evaluation of microvessels in colorectal tumors by narrow band imaging magnification

    Gastrointest Endosc

    (2007)
  • R.M. Cothren et al.

    Detection of dysplasia at colonoscopy using laser-induced fluorescence: a blinded study

    Gastrointest Endosc

    (1996)
  • M.A. Mycek et al.

    Colonic polyp differentiation using time-resolved autofluorescence spectroscopy

    Gastrointest Endosc

    (1998)
  • B. Mayinger et al.

    Endoscopic light-induced autofluorescence spectroscopy for the diagnosis of colorectal cancer and adenoma

    J Photochem Photobiol B

    (2003)
  • T.D. Wang et al.

    In vivo identification of colonic dysplasia using fluorescence endoscopic imaging

    Gastrointest Endosc

    (1999)
  • J. Haringsma et al.

    Autofluorescence endoscopy: feasibility of detection of GI neoplasms unapparent to white light endoscopy with an evolving technology

    Gastrointest Endosc

    (2001)
  • A.L. McCallum et al.

    Evaluation of autofluorescence colonoscopy for the detection and diagnosis of colonic polyps

    Gastrointest Endosc

    (2008)
  • A.B. Wilmink

    Overview of the epidemiology of colorectal cancer

    Dis Colon Rectum

    (1997)
  • J.D. Potter

    Colorectal cancer: molecules and populations

    J Natl Cancer Inst

    (1999)
  • B. Vogelstein et al.

    Genetic alterations during colorectal-tumor development

    N Engl J Med

    (1988)
  • S.J. Winawer et al.

    Prevention of colorectal cancer by colonoscopic polypectomyThe National Polyp Study Workgroup

    N Engl J Med

    (1993)
  • D.K. Rex

    Maximizing detection of adenomas and cancers during colonoscopy

    Am J Gastroenterol

    (2006)
  • J.C. van Rijn et al.

    Polyp miss rate determined by tandem colonoscopy: a systematic review

    Am J Gastroenterol

    (2006)
  • T. Fujii et al.

    Flat adenomas in the United Kingdom: are treatable cancers being missed?

    Endoscopy

    (1998)
  • S. Tsuda et al.

    Flat and depressed colorectal tumours in a southern Swedish population: a prospective chromoendoscopic and histopathological study

    Gut

    (2002)
  • R.M. Soetikno et al.

    Prevalence of nonpolypoid (flat and depressed) colorectal neoplasms in asymptomatic and symptomatic adults

    JAMA

    (2008)
  • Cited by (0)

    Conflicts of interest The authors disclose the following: Dr van den Broek is supported by an unrestricted educational grant from Olympus Inc (Hamburg, Germany); Dr Fockens has received a research grant from Olympus Inc (Tokyo, Japan); and the Department of Gastroenterology at the Academic Medical Center was provided with loan endoscopic equipment by Olympus Inc. No disclosures were made to study participants.

    View full text