Mo1624 CLINICAL VALIDATION OF THE SIMPLE CLASSIFICATION FOR OPTICAL DIAGNOSIS OF DIMINUTIVE AND SMALL COLORECTAL POLYPS

Image enhanced endoscopy (IEE) allows for real-time optical diagnosis of colorectal polyps in order to replace histopathology. A novel classification system (SIMPLE classification) has recently been developed for optical diagnosis when using the novel Pentax Optivista IEE platform. The aim of this study was to evaluate the SIMPLE classification for optical polyp diagnosis in a prospective clinical study. Patients undergoing screening, diagnostic or surveillance colonoscopies were enrolled in the study. All colorectal polyps 1-10mm found underwent optical polyp diagnosis using the SIMPLE classification with either iScan or Optivista for image-enhanced endoscopy (IEE). Polyps were resected as per standard care and sent for histopathology analysis. Optical diagnosis and surveillance intervals were calculated based on SIMPLE criteria and compared to pathology-based results as reference. Primary outcome was the agreement of the surveillance intervals based on the SIMPLE classification with pathology-based surveillance intervals for 1-5mm colorectal polyps. Secondary outcomes included negative predictive value (NPV) for rectosigmoid adenoma, percentage of pathology avoided, percentage of post-colonoscopy immediate recommendations, and surveillance interval agreement, rectosigmoid NPV for 1-10mm polyps. 399 patients (mean age: 62.4, 55.6% female) with 278 diminutive and 364 small polyps were evaluated in the study cohort. For ≤5mm polyps, agreement with pathology-based surveillance intervals was 93.5% [95% CI 91.1-95.9] (shorter: 4.5% [95% CI 2.5-6.5]; longer: 1.8% [95% CI 0.5-3.0]). NPV for rectosigmoid adenomatous polyps (including SSA) was 85.5% [95% CI 77.6-93.4]. Using Optical diagnosis and the SIMPLE classification, pathology analysis could be avoided in 61.5% [95% CI 56.9-66.2] of polyps and post-colonoscopy immediate surveillance interval recommendation could be given in 70.9% [95% CI 66.5-75.4] of patients. For ≤10mm polyps, agreement with pathology-based surveillance intervals was 92.2% [95% CI 89.6-94.9] (shorter: 5.5% [95% CI 3.3-7.8]; longer: 2.3% [95% CI 0.8-3.7]). NPV for rectosigmoid adenomatous polyps (including SSA) was 83.7% [95% CI 75.9-91.5]. The first clinical validation study using the SIMPLE classification in combination with Optivista or iScan IEE showed a high (≥90%) surveillance interval agreement compared to pathology. More than 60% of pathology could be avoided, and most patients could be given immediate surveillance intervals when using IEE in combination with the SIMPLE classification.