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Blue laser imaging-bright improves real-time detection rate of early gastric cancer: a randomized controlled study.

Dohi O1, Yagi N2, Naito Y1, Fukui A4, Gen Y4, Iwai N1, Ueda T1, Yoshida N1, Kamada K1, Uchiyama K1, Takagi T1, Konishi H1, Yanagisawa A4, Itoh Y1.

Gastrointest Endosc. 2018 Sep 3. pii: S0016-5107(18)33008-6. doi: 10.1016/j.gie.2018.08.049. [Epub ahead of print]

Background and aims: Blue laser imaging (BLI)-bright (BLI-bright) has shown promise as a more useful tool for detection of early gastric cancer (EGC) than white-light imaging (WLI). However, the diagnostic performance of BLI-bright in the detection of EGC has not been investigated. We aimed to compare real-time detection rates of WLI with that of BLI-bright for EGC.

Methods: This was a prospective, randomized, controlled study in 2 Japanese academic centers. We investigated 629 patients undergoing follow-up endoscopy for atrophic gastritis with intestinal metaplasia or surveillance after endoscopic resection of EGC. Patients were randomly assigned to receive primary WLI followed by BLI-bright or primary BLI-bright followed by WLI. The real-time detection rates of EGC were compared between primary WLI and primary BLI-bright.

Results: Of 298 patients in each group, the real-time detection rate of EGC with primary BLI-bright was significantly greater than that with primary WLI (93.1% vs 50.0%; p = 0.001). Primary BLI-bright had a significantly greater ability to detect EGCs in patients with a history of endoscopic resection for EGC, an HP-negative stomach after eradication therapy, lesions with an open-type atrophic border, lesions in the lower third of the stomach, depressed-type lesions, small lesions measuring <10 mm and 10 to 20 mm in diameter, reddish lesions, well-differentiated adenocarcinomas, and lesions with a depth of invasion of T1a.

Conclusions: BLI-bright has a higher real-time EGC detection rate than WLI. BLI-bright should be performed during surveillance endoscopy in patients at high risk for EGC.

1 Department of Molecular Gastroenterology and Hepatology, Graduate School of Medical Science, Kyoto Prefectural University of Medicine, Kyoto, Japan
2 Department of Gastroenterology and Hepatology, North Medical Center, Kyoto Prefectural University of Medicine, Kyoto, Japan
3 Department of Gastroenterology, Murakami Memorial Hospital, Asahi University, Gifu, Japan
4 Department of Surgical Pathology, Graduate School of Medical Science, Kyoto Prefectural University of Medicine, Kyoto, Japan

Blue Laser Imaging with a Small-Caliber Endoscope Facilitates Detection of Early Gastric Cancer.

Takahashi H1, Miura Y1, Osawa H1, Takezawa T1, Ino Y1, Okada M1, Lefor AK2, Yamamoto H1.

Clin Endosc. 2018 Aug 14. doi: 10.5946/ce.2018.100. [Epub ahead of print]

Abstract: Conventional endoscopy often misses early gastric cancers with minimal red discoloration because they cannot be distinguished from inflamed mucosa. We treated a patient with a small early gastric cancer that was difficult to diagnose using conventional endoscopy. Conventional endoscopy using a small-caliber endoscope showed only subtle red discoloration of the gastric mucosa. However, blue laser imaging showed a clearly discolored area measuring 10 mm in diameter around the red lesion, which was distinct from the surrounding inflamed mucosa. Irregular vessels on the tumor surface (suspicious for early gastric cancer) were observed even with small-caliber endoscopy. Biopsy revealed a well-moderately differentiated tubular adenocarcinoma, and endoscopic submucosal dissection was performed. Histopathological examination of the specimen confirmed well-moderately differentiated adenocarcinoma localized to the mucosa with slight depression compared to the surrounding mucosa, consistent with the endoscopic findings. This small early gastric cancer became clearly visible with blue laser imaging using small-caliber endoscopy.

1 Division of Gastroenterology, Department of Medicine
2 Department of Surgery, Jichi Medical University, Shimotsuke, Tochigi, Japan

Additional Thirty Seconds Observation with Linked Color Imaging Improves Detection of Missed Polyps in the Right-Sided Colon.

Yoshida N1, Inada Y2, Yasuda R1, Murakami T1, Hirose R1, Inoue K1, Dohi O1, Naito Y1, Ogiso K3, Morinaga Y4, Kishimoto M4, Konishi E4, Itoh Y1.

Gastroenterol Res Pract. 2018 Jul 8;2018:5059834. doi: 10.1155/2018/5059834. eCollection 2018.

Background and aims: Missed polyps are a pitfall of colonoscopy. In this study, we analyzed the efficacy of an additional 30 seconds observation using linked color imaging (LCI) for detecting adenoma and sessile serrated adenoma/polyp (SSA/P).

Materials and methods: We enrolled patients undergoing colonoscopy from February to October 2017 in two institutions. In all patients, the cecum and ascending colon were observed with white light imaging (WLI) first. The colonoscope was inserted again, and the cecum and ascending colon were observed for an additional 30 seconds using either LCI or WLI. The method for the 30 sec observation was to insufflate the cecum and ascending colon sufficiently and observe them in a distant view, because the length of the second observation was determined to be precisely 30 sec. For the second observation, LCI was performed for the first 65 patients and WLI for the next 65. Adenoma and SSA/P detection rate (ASDR) in the second observation were examined in both groups. According to a pilot study, the sample size was estimated 65.

Results: In the first observation, ASDR were 30.7% in the LCI group and 32.2% in the WLI group (p = 0.85). For the second observation, 13 polyps were detected in the LCI group and 5 polyps in the WLI group (p = 0.04). Additionally, ASDR for the second observation were 18.5% and 6.1%, respectively (p = 0.03). There were no significant differences between the LCI and WLI groups with respect to morphology (ratio of polypoid) (38.5% versus 60.0%, p = 0.52) and histology (ratio of adenoma) (92.3% versus 100.0%, p = 0.91). Total adenoma and SSA/P number were 48 in the LCI group and 36 in the WLI group (p = 0.02).

Conclusion: The 30 seconds additional observation with LCI improved the detection of adenoma and SSA/P in the right-sided colon.

1 Department of Molecular Gastroenterology and Hepatology, Kyoto Prefectural University of Medicine, Graduate School of Medical Science, Kyoto, Japan
2 Department of Gastroenterology, Fukuchiyama City Hospital, Kyoto, Japan
3 Department of Gastroenterology, Osaka General Hospital of West Japan Railway Company, Osaka, Japan
4 Department of Surgical Pathology, Kyoto Prefectural University of Medicine, Graduate School of Medical Science, Kyoto, Japan

Usefulness of close observation with non-magnified blue laser imaging for determining cold polypectomy indications.

Suzuki T1, Kitagawa Y1, Nankinzan R1, Takashiro H2, Hara T3, Yamaguchi T2.

Scand J Gastroenterol. 2018 Jul 24:1-5. doi: 10.1080/00365521.2018.1488181

Purpose: To examine the usefulness of non-magnified close observation with blue laser imaging (BLI) using a colonoscope with close observation capability in determining indications for cold polypectomy.

Methods: We conducted an image evaluation study on 100 consecutive colorectal lesions of 10 mm or less which were observed endoscopically without magnification using BLI mode prior to treatment. Two experts and two non-experts reviewed the images using the Japan NBI expert team (JNET) classification and the diagnostic accuracy was analyzed.

Results: The final pathological diagnoses of the 100 lesions were hyperplastic/sessile serrated polyp (HP/SSP), low grade dysplasia (LGD), high grade dysplasia (HGD) and deep submucosal invasive cancer (dSM), respectively, in 12, 79, 9 and 0 lesions. When JNET classification type 1 corresponds to HP/SSP; 2A to LGD; 2B to HGD; and 3 to dSM; the overall diagnostic accuracy was 84.3%. Accuracy was 90.5% for experts and 78.0% for non-experts. High confidence rate was 67.5% for experts and 48.0% for non-experts. In diagnostic accuracy for HGD, the sensitivity, specificity, PPV and NPV were, respectively, 77.8%, 98.9%, 87.5% and 97.8% for experts; and 66.6%, 92.3%, 46.2% and 96.6% for non-experts.

Conclusions: The diagnostic accuracy of unmagnified close observation with BLI using a colonoscope with close observation capability is similar to that reported for magnifying endoscopy and is useful in predicting the histological diagnosis of colorectal polyps of 10 mm or less although the effectiveness may be limited for non-experts. This modality is a potentially useful tool in deciding indications for cold polypectomy.

1 Department of Endoscopy, Chiba Cancer Center, Chiba, Japan
2 Department of Gastroenterology, Chiba Cancer Center, Chiba, Japan
3 Hara Clinic

Lavender Color in Linked Color Imaging Enables Noninvasive Detection of Gastric Intestinal Metaplasia.

Ono S1, Kato M1, Tsuda M1, Miyamoto S1, Abiko S1, Shimizu Y1, Sakamoto N1

Digestion. 2018 Jul 25;98(4):222-230. doi: 10.1159/000489454

Background and aims: Recently, there have been some reports that image-enhanced endoscopy may improve detection of gastric intestinal metaplasia (GIM). Our aim was to determine the usefulness of linked color imaging (LCI) for detection of GIM.

Methods: In prospectively recruited patients, the whole antrum was observed by white light imaging (WLI) followed by LCI. When a whitish flat elevation (WFE) in WLI and a lavender color sign (LCS) in LCI were detected, target biopsies were performed after LCI. Random biopsies were performed in patients who had neither WFE nor LCS. The primary endpoint was the diagnostic accuracy of GIM per patient in WLI and LCI and the secondary endpoints were that of GIM per biopsy and interobserver agreement.

Results: Data from 128 patients were analyzed and 58 patients (45.3%) had histological GIM in the antrum. The per-patient yields of WLI and LCI to detect GIM were 19.0% (11/58) and 91.4% (53/58) respectively. Diagnostic accuracies of target biopsies for GIM were 23.7% in WLI and 84.2% in LCI. Kappa values among 3 doctors were 0.60 for WFE and 0.78 for LCS respectively.

Conclusion: LCI could be a new diagnostic tool for detecting GIM during routine endoscopy.

1 Division of Endoscopy, Hokkaido University Hospital, Sapporo, Japan

Artificial intelligence diagnosis of Helicobacter pylori infection using blue laser imaging-bright and linked color imaging: a single-center prospective study.

Nakashima H1, Kawahira H2, Kawachi H3, Sakaki N1.

Ann Gastroenterol. 2018 Jul-Aug;31(4):462-468. doi: 10.20524/aog.2018.0269. Epub 2018 May 3.

Background: Deep learning is a type of artificial intelligence (AI) that imitates the neural network in the brain. We generated an AI to diagnose Helicobacter pylori (H. pylori) infection using blue laser imaging (BLI)-bright and linked color imaging (LCI). The aim of this pilot study was to establish an AI diagnosing system that predicts H. pylori infection status using endoscopic images to improve the accuracy and productivity of endoscopic examination.

Methods: A total of 222 enrolled subjects (105 H. pylori-positive) underwent esophagogastroduodenoscopy and a serum test for H. pylori IgG antibodies. During esophagogastroduodenoscopy, an endoscopist sequentially took 3 still images of the lesser curvature of the stomach using white light imaging (WLI), BLI-bright, and LCI. EG-L580NW endoscopic equipment (FUJIFILM Co., Japan) was used for the study. The specifications of the AI were as follows: operating system, Linux; neural network, GoogLeNet; framework, Caffe; graphic processor unit, Geforce GTX TITAN X (NVIDIA Co., USA).

Results: The area under the curve (AUC) on receiver operating characteristics analysis was 0.66 for WLI. In contrast, the AUCs of BLI-bright and LCI were 0.96 and 0.95, respectively. The AUCs obtained for BLI-bright and LCI were significantly larger than those for WLI (P<0.01).

Conclusion: The results demonstrate that the developed AI has an excellent ability to diagnose H. pylori infection using BLI-bright and LCI. AI technology with image-enhanced endoscopy is likely to become a useful image diagnostic tool.

1 Foundation for Detection of Early Gastric Carcinoma, Tokyo (Hirotaka Nakashima, Nobuhiro Sakaki)
2 Center for Frontier Medical Engineering, Chiba University, Chiba (Hiroshi Kawahira)
3 Department of Pathology, The Cancer Institute Hospital, Japanese Foundation for Cancer Research, Tokyo (Hiroshi Kawachi), Japan