Background and study aims: 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).
