Background: In this study, we aimed to compare the accuracy for optical diagnosis of diminutive colorectal polyps between a CADx system (POLAR system) and endoscopists during real-time colonoscopy, including sessile serrated lesions (SSLs).
Patients and methods: We developed the POLAR system, capable of performing real-time characterization of diminutive colorectal polyps. For pre-training, the Microsoft-COCO dataset with non-polyp object images (300k) was used. For training, 8 hospitals prospectively collected 2.637 annotated images from 1.339 polyps (i.e. new publicly available POLAR database). For clinical validation, POLAR was tested during colonoscopy in fecal immunochemical test (FIT)-positive individuals, and compared with the performance of 20 endoscopists from 8 hospitals. Endoscopists were blinded to the POLAR outcome. Primary outcome was the comparison of accuracy in the optical diagnosis of diminutive colorectal polyps between POLAR and endoscopists (neoplastic [adenomas and SSLs] vs non-neoplastic [hyperplastic polyps]). Histopathology served as the reference standard.
Results: During clinical validation, a total of 423 diminutive polyps detected in 194 FIT-positive individuals were included for analysis (300 adenomas, 41 SSLs, 82 hyperplastic polyps). POLAR distinguished neoplastic from non-neoplastic lesions with 79% accuracy, 89% sensitivity and 38% specificity. The endoscopists achieved 83% accuracy, 92% sensitivity, and 44% specificity. The optical diagnosis accuracy between POLAR and endoscopists was not significantly different (P=.10). The success rate for acquiring a histological prediction by POLAR was 98%.
Conclusions: We have developed a CADx system that differentiated neoplastic from non-neoplastic diminutive polyps during endoscopy with an accuracy comparable to the accuracy of screening endoscopists, with near-perfect technical efficacy.