Is LCI the best for virtual chromoendoscopy?

based on optic filters that select wavelengths of light that correspond to the peak light absorption of hemoglobin, and the further systems that digitally process endoscopic images to provide a series of wavelengths of light, such as Fuji Intelligent Chromo Endoscopy (FICE) and i-Scan, there has been a great improvement in colorectal lesions characterization, delineation and classification, specially when combined to high-optical magnification. However, when it comes to colorectal polyps or adenoma detection, virtual chromoendoscopy techniques have not demonstrated significant improvement over white-light endoscopy (WLE) in colonoscopy screening targeting an average-risk population. A meta-analysis of 42 studies concluded that only conventional dye-based chromoendoscopy was associated with an increase in adenoma detection rate (ADR) in comparison to NBI, FICE, i-Scan, autofluorescence imaging and cap-assisted colonoscopy [1]. Another single-center randomized controlled trial (RCT) enrolling 1650 patients also showed no difference in ADR and adenoma miss rate between virtual chromoendoscopy with NBI or FICE and WLE [2]. More recently, a second generation of equipment-based image-enhanced endoscopy (IEE) technologies has been launched, which includes NBI in the latest Olympus scopes (2GNBI); i-Scan Optical Enhancement from Pentax; Blue Laser Imaging (BLI) and Linked Color Imaging (LCI) from Fujifilm [3]. The new generation of IEE technologies has improved the brightness of the light source, offering a better quality of image and overcoming the darkness associated with far-field examination in earlier versions [3]. Conceivably, the new generation of IEE could perform much better in detection of superficial neoplastic lesions and could be a powerful tool for colorectal cancer screening. LCI particularly has been accepted with enthusiasm due to the lighter colors and brighter image that resembles WLE, and the more reddish appearance of mucosal abnormalities in comparison with NBI and BLI. A multicenter prospective RCT in China demonstrated that LCI increased ADR and sessile serrated polyp detection compared to WLE [4]. Another RCT, designed in Japan, reported an improvement in polyp detection rate in the right colon by six non-expert endoscopists with use of LCI (92.3 ± 2.3% with LCI vs. 72.7 ± 11.5% with WLE; P<0.01) [5]. Moreover, a recently published European RCT revealed a reduction in the adenoma miss rate with use of LCI in comparison to WLE (11.8% vs 30.6%; P<0.001) [6]. In this issue of Endoscopy International Open, Sakamoto et al. [7] from National Cancer Center Hospital (NCCH) in Japan report an interesting study aiming to evaluate the additional benefit of LCI in detection of colorectal polyps compared to WLE in the insertion phase of colonoscopy. The authors enrolled 138 patients equally distributed into two groups: colonoscope insertion with WLE or with LCI. All patients underwent colonoscope withdrawal from cecum to rectum under LCI imaging. A single, experienced endoscopist carried out all procedures. Interestingly no difference was noted in detection of right colon polyps, because the majority of lesions were detected during scope withdrawal. In addition, the efficacy of LCI for detection of advanced adenomas (> 10mm, villous component or presence of high-grade dysplasia) was not superior to WLE. However, in the left colon, particularly in the sigmoid, more polyps were detected during insertion with LCI imaging than with WLE, 16% out of 48 lesions for LCI against 0% in the WLE group (P= 0.045). Of note, most of the lesions detected were small tubular adenomas smaller than 5mm. The authors concluded that colonoscopy with LCI improves colorectal polyp detection during the insertion phase of the examination. Many investigators have studied whether use of virtual chromoendoscopy is superior to WLE in detection of colorectal Is LCI the best for virtual chromoendoscopy?