Narrow Band Versus Conventional Endoscopic Imaging for Screening Colonoscopy
Condition: Adenoma
MeSH terms: Adenoma
Study type: Interventional

Summary: 
      Narrow Band Imaging (NBI) with high-definition (HDTV) visualization has been implemented into
      GI endoscopy with the purpose to better highlight endoluminal pathological structures by
      improving their contrast. Previous studies from referral centers could not show significant
      differences in terms of colonoscopic adenoma detection rate, but either very high adenoma
      rates or some numerical differences suggested that some benefit may exist which may become
      evident with average adenoma rates and/or large case numbers.

      In a prospective randomized trial performed exclusively in a multicenter private practice
      setting involving 6 examiners with substantial life-time experience (>10.000 colonoscopies)
      1200 patients will undergo HDTV screening colonoscopy with either NBI or conventional imaging
      technique on instrument withdrawal. Primary outcome measure is the adenoma detection rate
      (ADR; i.e. number of adenomas per patient).
    

Detailed description: 
      in 5 private practices with 6 examiners, consecutive asymptomatic persons willing to undergo
      screening colonoscopy will be asked to participate in this randomized study.

      After introduction of the colonoscope into the cecum, patients will be randomized into
      withdrawal with either the NBI mode or conventional imaging by using wide-angle colonoscopes
      with HDTV imaging (Olympus Corp., Hamburg, Germany) in both groups. Randomization lists will
      be used for group allocation in each individual practice. In the NBI group, switching back to
      conventional imaging, and the number of occasions for switching back and the reasons for it
      are documented in this group.

      Patients bowel preparation consists mostly of polyethylene glycol lavage with 4-5 liters
      until clear rectal fluid is evacuated. All examiners shall take special care to wash and
      clean the entire large bowel during instrument introduction and withdrawal, in order to
      provide optimal imaging conditions.

      The following parameters are documented:

        -  Age and sex of the patient

        -  Type and dosage of sedation

        -  Examination time, both for instrument introduction and withdrawal

        -  Polyp characteristics: size (measured by open forceps or snare), shape
           (pedunculated/elevated, sessile/flat, and location

        -  Polyp histology after removal using snare polypectomy or forceps removal (for polyps < 3
           mm), or biopsy if there are contraindications

        -  Other lesions found such as cancers, diverticula, inflammatory lesions etc. The main
           outcome parameter is the adenoma detection rate (number of polyps/number of patients
           examined) in the two groups.

      Secondary outcome measures include analysis of the total number of polyps, flat/sessile
      adenomas, small adenomas (< 1 cm), hyperplastic polyps with size determination and
      right-sided versus left-sided polyp location in both groups.
    

Intervention name(s): Olympus NBI colonoscope 180 HDTV narrow band imaging (diagnostic test)
Intervention type(s): Device
Intervention description(s): colonoscopy withdrawal with NBI mode
Other intervention name(s): Olympus NBI colonoscope 180 HDTV
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: None (Open Label)
Primary purpose: Diagnostic
Keywords: colonoscopy; narrow band imaging; adenoma; diagnosis; colonoscopic adenoma detection