Linked color imaging improves colorectal lesion detection especially for low performance endoscopists: An international trial in Asia.

BACKGROUND AND AIM: Linked color imaging (LCI) is an image-enhanced endoscopy technique that accentuates the color difference between red and white, potentially improving the adenoma detection rate (ADR). However, it remains unclear whether LCI performance in detecting colorectal lesions differs based on endoscopists' experience levels. We aimed to evaluate the differences in LCI efficacy based on the experience levels of endoscopists by conducting an exploratory analysis. METHODS: In this post hoc analysis of an international randomized controlled trial comparing the detection of adenoma and other lesions using colonoscopy with LCI and high-definition white light imaging (WLI), we included patients from 11 institutions across four countries/regions: Japan, Thailand, Taiwan, and Singapore. We retrospectively reviewed differences in the lesion detection of LCI according to endoscopists' colonoscopy history or ADR. RESULTS: We included 1692 and 1138 patients who underwent colonoscopies performed by 54 experts (experience of ≥ 5000 colonoscopies) and by 43 non-experts (experience of < 5000 colonoscopies), respectively. Both expert and non-expert groups showed a significant improvement in ADR with LCI compared to WLI (expert, 61.7% vs 46.4%; P < 0.001; non-expert, 56.6% vs 46.4%; P < 0.001). LCI had no effect on sessile serrated lesion detection rate in non-experts (3.1% vs 2.5%; P = 0.518). LCI significantly improved detection rates in endoscopists with relatively low detection performance, defined as an ADR < 50%. CONCLUSIONS: This exploratory study analyzed data from a previous trial and revealed that LCI is useful for both experts and non-experts and is even more beneficial for endoscopists with relatively low detection performance using WLI.

Detection of Colorectal Neoplasms Using Linked Color Imaging: A Prospective, Randomized, Tandem Colonoscopy Trial.

BACKGROUND AND AIMS: A higher adenoma detection rate (ADR) has been shown to be related to a lower incidence and mortality of colorectal cancer. We analyzed the efficacy of linked color imaging (LCI) by assessing the detection, miss, and visibility of various featured adenomas as compared with white light imaging (WLI). METHODS: This was a prospective, randomized, tandem trial. The participants were randomly assigned to 2 groups: first observation by LCI, then second observation by WLI (LCI group); or both observations by WLI (WLI group). Suspected neoplastic lesions were resected after magnifying image-enhanced endoscopy. The primary outcome was to compare the ADR during the first observation. Secondary outcomes included evaluation of adenoma miss rate (AMR) and visibility score. RESULTS: A total of 780 patients were randomized, 700 of whom were included in the final analysis. The ADR was 69.6% and 63.2% in the LCI and WLI groups, respectively, with no significant difference. However, LCI improved the average ADR in low-detectors compared with high-detectors (76.0% vs 55.1%; P < .001). Total AMR was 20.6% in the LCI group, which was significantly lower than that in the WLI group (31.1%) (P < .001). AMR in the LCI group was significantly lower, especially for diminutive adenomas (23.4% vs 35.1%; P < .001) and nonpolypoid lesions (25.6% vs 37.9%; P < .001) compared with the WLI group. CONCLUSION: Although both methods provided a similar ADR, LCI had a lower AMR than WLI. LCI could benefit endoscopists with lower ADR, an observation that warrants additional study. (UMIN Clinical Trials Registry, Number: UMIN000026359).

Endoscopic Ultrasound Elastography as a Novel Diagnostic Method for the Assessment of Hardness and Depth of Invasion in Colorectal Neoplasms.

INTRODUCTION: We aimed to compare the efficacy of endoscopic ultrasound elastography (EUS-EG) with that of magnifying chromoendoscopy (MCE) and endoscopic ultrasonography (EUS) for the diagnosis of the depth of invasion in colorectal neoplasms. This is an important clinical issue as the depth of invasion is associated with the risk of metastasis. METHODS: Consecutive patients with suspected superficial colorectal neoplasms, evaluated by MCE, EUS, and EUS-EG, for whom endoscopic submucosal dissection was considered, were enrolled in 2018 (derivation study) and in 2019-2020 (validation study). The primary clinical endpoint was the diagnostic yield differentiating intramucosal and shallow submucosal neoplasms from deep submucosal (dSM) and advanced colorectal cancers. In addition, inter- and intra-observer agreements of the elastic score of colorectal neoplasm (ES-CRN) were evaluated by 2 expert and 2 non-expert endoscopists. RESULTS: Thirty-one (33 lesions) and 50 (55 lesions) patients were enrolled in the derivation and validation studies, respectively. Sensitivity, specificity, positive, and negative predictive values, and accuracy of assessment of the depth of submucosal or deeper invasion in the derivation and validation groups were as follows: EUS-EG, 100/88.2/86.7/100/93.3% and 77.8/86.1/73.7/88.6/83.3%; MCE, 66.7/94.4/90.9/77.3/81.8% and 84.2/91.4/84.2/91.4/88.9%; and EUS, 93.3/77.8/77.8/93.3/84.8% and 89.5/65.7/58.6/92.0/74.1%, respectively. For the 2 expert endoscopists, interobserver agreement for the ES-CRN (first and second assessments) in the derivation group was 0.84 and 0.78, respectively; these values were 0.73 and 0.49, respectively, for the 2 non-expert endoscopists. DISCUSSION/CONCLUSION: All 3 modalities presented similar diagnostic yield. Inter- and intra-observer agreements of the ES-CRN were substantial, even for non-expert endoscopists. Therefore, EUS-EG may be a useful modality in determining the depth of invasion in colorectal neoplasms.