Accuracy of the Optical Diagnosis of Small Colonic Polyps Using the Nice Classification
Condition: Colon Adenoma; Colorectal Carcinoma; Hyperplastic Polyp
MeSH terms: Adenoma; Colorectal Neoplasms; Polyps
Study type: Observational

Summary: 
      Adenomas and hyperplastic polyps are polypoid lesion and may occur at any location in the
      colon. At the present moment, all polyps should be resected endoscopically, although only
      adenomas, but not hyperplastic polyps have the potential to develop colorectal cancer. This
      approach enables the conduction of microscopic investigations of the lesions. By today, only
      the pathological diagnosis can distinguish exactly between adenomas and hyperplastic polyps.
      Some studies have investigated the value of the socalled optical biopsy method. Optical
      biopsy means the visual assessment of the polyp and the determination of a diagnosis solely
      on behalf of optical criteria. This method is conducted in real time during colonoscopy. If
      it can be shown, that endoscopist using optical biopsy are able to predict histopathological
      diagnoses of colonic polyps sufficiently this would possibly lead to simplification of
      diagnostic procedures. For instance, it would be conceivable to resect hyperplastic polyps
      and small adenomas and discard them without further assessment by a pathologist.
      Gastroenterological societies demand for a 90 percent accordance between diagnoses set by
      endoscopists and pathologists as a prerequisite for the implementation of the optical biopsy
      method.

      In this study we want to proof that the use of a new narrow-band imaging (NBI) tool (Exera
      III, Olmpus) is capable to rise accuracy of optically ascertained diagnoses of colonic
      polyps. NBI is a light filter tool which can be activated by pressing a button at the
      endoscope. NBI function leads to an endoscopic picture which appears blue and enables
      endoscopists to better assess surface structures and vascular patterns.

      In a prospective randomised multicenter setting we plan to conduct colonoscopy in 380
      patients. Half of the patients will be examined without use of NBI (control arm). In these
      cases colonoscopists will assess optical diagnosis of polyps without turning on the NBI tool.
      If polyps are detected in patients belonging to the intervention arm NBI will be used and
      optical diagnosis will be determined using the NICE (NBI International Colorectal Endoscopic)
      classification. All polyps will be resected and send to pathology for further microscopic
      assessment. After completing the trial we aim to compare accuracy of the optical diagnosis in
      both groups. Our hypothesis is, that by using the new NBI tool accuracy (accordance between
      optical and histopathological diagnosis) can be increased from 78% to 90%.
    


Intervention name(s): NBI Function
Intervention type(s): Procedure
Other intervention name(s): NBI Function integrated in the CF-HQ 190 EVIS Exera III Advanced Diagnostic Video Colonoscope
Observational model: Cohort
Time perspective: Prospective
Sampling method: Probability Sample
Study population: 
        Patients will be recruited at the three participating study centers (Munich, Frankfurt,
        Berlin). Two of the three centers are tertiary referral-centres whereas the last one is a
        major regional hospital. All patients undergo colonoscopy for medical indications.
      
Biospecimen description: 
      Colon polyps
    
Keywords: Colonoscopy; Adenoma detection rate; Narrow band imaging; Optical biopsy; Accuracy