title: Narrow-band imaging in the prediction of surveillance intervals after polypectomy in community practice.
abstract: OBJECTIVE
  It has been proposed that the use of narrow-band imaging (NBI) for real-time histological assessment to determine postpolypectomy surveillance intervals is a cost-effective approach to the management of diminutive polyps. However, significant discrepancies in NBI performance have been observed among endoscopists; hence, professional societies recommend training, monitoring, and auditing. The aim of the present study was to evaluate the performance of real-time optical diagnosis for diminutive polyps after the inclusion of this approach in an internal quality assurance program, in order to assess its applicability in clinical practice Patients and methods: Four endoscopists attended periodic training sessions on NBI assessment of polyp histology before and during the study. Performance was audited and periodic feedback was provided. The accuracy of high-confidence NBI evaluation for polyps ≤ 5 mm in predicting surveillance intervals according to the European and US guidelines, and the negative predictive value (NPV) for adenoma in the rectosigmoid were calculated and compared with recommended thresholds (90 % agreement and 90 % NPV, respectively).
  
  
  RESULTS
  Overall, 284 outpatients (mean age 61.3 ± 18.2 years; 63 % males) were enrolled. A total of 656 polyps were detected, 465 of which (70.9 %) were diminutive (70.5 % adenomas). Sensitivity, specificity, positive and negative predictive values, and accuracy of high-confidence NBI predictions for adenoma in diminutive lesions were 95.3 %, 83.5 %, 93.5 %, 87.6 %, and 91.9 %, respectively. High-confidence characterization of diminutive polyps predicted the correct surveillance interval in 95.8 % and 93.3 % of cases according to European and American guidelines, respectively. NPV for adenoma in the rectosigmoid was 91.3 %
  
  
  CONCLUSIONS
  For community settings in which endoscopists are adequately trained and performance is periodically audited, real-time optical diagnosis for diminutive polyps is sufficiently accurate to avoid postpolypectomy histological examination of resected lesions, or to leave rectosigmoid hyperplastic polyps in place. Trial registered at ClinicalTrials.gov (NCT02196402).
authors.affiliation: Gastroenterology Unit, Valduce Hospital, Como, Italy.
authors.forename: Silvia
authors.initials: S
authors.lastname: Paggi
authors.affiliation: Gastroenterology Unit, Valduce Hospital, Como, Italy.
authors.forename: Emanuele
authors.initials: E
authors.lastname: Rondonotti
authors.affiliation: Gastroenterology Unit, Valduce Hospital, Como, Italy.
authors.forename: Arnaldo
authors.initials: A
authors.lastname: Amato
authors.affiliation: Department of Medical and Surgical Sciences, University of Bologna, S. Orsola-Malpighi Hospital, Bologna, Italy.
authors.forename: Lorenzo
authors.initials: L
authors.lastname: Fuccio
authors.affiliation: Gastroenterology Unit, Valduce Hospital, Como, Italy.
authors.forename: Alida
authors.initials: A
authors.lastname: Andrealli
authors.affiliation: Gastroenterology Unit, Valduce Hospital, Como, Italy.
authors.forename: Giancarlo
authors.initials: G
authors.lastname: Spinzi
authors.affiliation: Gastroenterology Unit, Valduce Hospital, Como, Italy.
authors.forename: Franco
authors.initials: F
authors.lastname: Radaelli
mesh_terms: D000236:Adenoma / Q000175:diagnosis*; D000328:Adult; D000368:Aged; D003110:Colonic Neoplasms / Q000175:diagnosis*; D003111:Colonic Polyps / Q000175:diagnosis* / Q000601:surgery; D003113:Colonoscopy; D003937:Diagnosis, Differential; D006764:Hospitals, Community; D006801:Humans; D008875:Middle Aged; D062048:Narrow Band Imaging; D011159:Population Surveillance; D011237:Predictive Value of Tests; D011446:Prospective Studies; D013997:Time Factors