Prospective study of additional effects of flexible spectral image color enhancement (FICE) installed in colon capsule endoscopy (CCE) in the diagnosis of colorectal polyps and tumors.

Aims: CCE is expected as a new modality of colorectal cancer screening. Diagnostic yield of CCE for >5 mm colorectal polyps/tumors (CRT) compared with conventional colonoscopy (CS) was reported to be 94%, but little is known about the additional effect of FICE in their diagnosis. Methods: Between January 2014-December 2016, 33 patients with CRTs were enrolled in this study including CS within four months after CCE. One endoscopist interpreted white light (WL) images only, and the other interpreted FICE images only. On the basis of CS findings as the gold standard, CRT detectability between WL and FICE imaging was compared. We excluded 8 patients and finally analyzed data from 25 patients. Results: At CS, 25 patients had 97 CRTs (the median diameter, 5 (1-30) mm; 48 with <5mm/37 with 5-9mm/12 with >9mm CRTs; 75 flat/22 elevated CRTs; 49 with tubular adenomas/46 with SSA/P or hyperplastic polyps/2 with adenocarcinomas). Overall CRT detection rates of CCE-WL and CCE-FICE were 45% and 70%, respectively (P= 0.00002). Subanalyses also showed significance in <5 mm, 5-9 mm CRTs, flat CRTs, tubular adenomas (P= 0.003, 0.008, 0.00002, 0.002, respectively). Conclusions: CCE-FICE contributed to the additional diagnostic accuracy probably because of enhancement of CRT itself and surrounding blood vessels.