Enhanced magnifying endoscopy for differential diagnosis of superficial gastric lesions identified with white-light endoscopy

Endoscopic detection and diagnosis of gastric cancer using image-enhanced endoscopy: A systematic review and meta-analysis

OBJECTIVES

We aimed to conduct a systematic review and meta-analysis to assess the value of image-enhanced endoscopy including blue laser imaging (BLI), linked color imaging, narrow-band imaging (NBI), and texture and color enhancement imaging to detect and diagnose gastric cancer (GC) compared to that of white-light imaging (WLI).

METHODS

Studies meeting the inclusion criteria were identified through PubMed, Cochrane Library, and Japan Medical Abstracts Society databases searches. The pooled risk ratio for dichotomous variables was calculated using the random-effects model to assess the GC detection between WLI and image-enhanced endoscopy. A random-effects model was used to calculate the overall diagnostic performance of WLI and magnifying image-enhanced endoscopy for GC.

RESULTS

Sixteen studies met the inclusion criteria. The detection rate of GC was significantly improved in linked color imaging compared with that in WLI (risk ratio, 2.20; 95% confidence interval [CI], 1.39-3.25; p < 0.01) with mild heterogeneity. Magnifying endoscopy with NBI (ME-NBI) obtained a pooled sensitivity, specificity, and area under the summary receiver operating curve of 0.84 (95 % CI, 0.80-0.88), 0.96 (95 % CI, 0.94-0.97), and 0.92, respectively. Similarly, ME-BLI showed a pooled sensitivity, specificity, and area under the curve of 0.81 (95 % CI, 0.77-0.85), 0.85 (95 % CI, 0.82-0.88), and 0.95, respectively. The diagnostic efficacy of ME-NBI/BLI for GC was evidently high compared to that of WLI, However, significant heterogeneity among the NBI studies still existed.

CONCLUSIONS

Our meta-analysis showed a high detection rate for linked color imaging and a high diagnostic performance of ME-NBI/BLI for GC compared to that with WLI.

Magnifying image-enhanced endoscopy-only mode boosted early cancer diagnostic efficiency: a multicenter randomized controlled trial

BACKGROUND AND AIMS

Magnifying image-enhanced endoscopy (MIEE) is an advanced endoscopy with image enhancement and magnification used in preoperative examination. However, its impact on the detection rate is unknown.

METHODS

We conducted an open-label, randomized, parallel (1:1:1), controlled trial in 6 hospitals in China. Patients were recruited between February 14, 2022 and July 30, 2022. Eligible patients were aged ≥18 years and undergoing gastroscopy in outpatient departments. Participants were randomly assigned to the MIEE-only mode (o-MIEE) group, white-light endoscopy-only mode (o-WLE) group, and MIEE when necessary mode (n-MIEE) group (initial WLE followed by switching to another endoscope with MIEE if necessary). Biopsy sampling of suspicious lesions of the lesser curvature of the gastric antrum was performed. Primary and secondary aims were to compare detection rates and positive predictive value (PPV) of early cancer and precancerous lesions in these 3 modes, respectively.

RESULTS

A total of 5100 recruited patients were randomly assigned to the o-MIEE (n = 1700), o-WLE (n = 1700), and n-MIEE (n = 1700) groups. In the o-MIEE, o-WLE, and n-MIEE groups, 29 (1.51%; 95% confidence interval [CI], 1.05-2.16), 4 (.21%; 95% CI, .08-.54), and 8 (.43%; 95% CI, .22-.85) early cancers were found, respectively (P < .001). The PPV for early cancer was higher in the o-MIEE group compared with the o-WLE and n-MIEE groups (63.04%, 33.33%, and 38.1%, respectively; P = .062). The same trend was seen for precancerous lesions (36.67%, 10.00%, and 21.74%, respectively).

CONCLUSIONS

The o-MIEE mode resulted in a significant improvement in diagnosing early upper GI cancer and precancerous lesions; thus, it could be used for opportunistic screening. (Clinical trial registration number: ChiCTR2200064174.).

Circular array transducer based-photoacoustic/ultrasonic endoscopic imaging with tunable ring-beam excitation

Photoacoustic/ultrasound endoscopic imaging is regarded as an effective method to achieve accurate detection of intestinal disease by offering both the functional and structural information, simultaneously. Compared to the conventional endoscopy with single transducer and laser spot for signal detection and optical excitation, photoacoustic/ultrasound endoscopic probe using circular array transducer and ring-shaped laser beam avoids the instability brought by the mechanical scanning point-to-point, offering the dual-modality imaging with high accuracy and efficiency. Meanwhile, considering the complex morphological environments of intestinal tracts in clinics, developing the probe having sufficient wide imaging distance range is especially important. In this work, we develop a compact circular photoacoustic/ultrasonic endoscopic probe, using the group of fiber, lens and home-made axicon, to generate relatively concentrated ring-shaped laser beam for 360° excitation with high efficiency. Furthermore, the laser ring size can be tuned conveniently by changing the fiber-lens distance to ensure the potential applicability of the probe in various and complex morphological environments of intestines. Phantom experimental results demonstrate imaging distance range wide enough to cover from 12 mm to 30 mm. In addition, the accessibility of the photoacoustic signals of molecular probes in ex vivo experiments at the tissue depth of 7 mm using excitation energy of 5 mJ has also been demonstrated, showing a high optical excitation efficiency of the probe.

Application of Endoscopic Ultrasound Combined with Multislice Spiral CT in Diagnosis and Treatment of Patients with Gastrointestinal Eminence Lesions

Objective

To evaluate the application of endoscopic ultrasound (EUS) combined with multislice spiral CT (MSCT) in the diagnosis and treatment of patients with gastric eminence lesions.

Methods

A total of 160 patients with gastric eminence lesions enrolled in our hospital from June 2018 to June 2021 were included and received EUS and MSCT. The results of the two examinations and the postoperative pathological results were compared.

Results

The common pathological types of gastric eminence lesions include polyps and stromal tumors, with the most common sites of lesions in the gastric antrum, followed by the fundus of the stomach and the gastric body. Gastric eminence lesions mostly originate from the mucosal layer and muscularis mucosa, accounting for 83.13% of the total. With pathological results as the gold standard, the detection rate of MSCT was 90.63%, and that of EUS was 78.13%. With the joint diagnosis as a reference, the receiver operating curve (ROC) revealed a higher diagnostic efficiency of MSCT and EUS.

Conclusion

The accuracy of MSCT in the diagnosis of gastric eminence lesions is significantly higher than that of EUS, both of which can offer useful guidance for the choice of endoscopic treatment methods. The combination of MSCT and EUS examination before endoscopic gastroscopy may provide a better treatment efficacy on gastric protruding lesions with high safety.

Proposal of minimum elements for screening and diagnosis of gastric cancer by an international Delphi consensus

The World Endoscopy Organization Stomach and Duodenal Diseases Committee extracted minimum elements for screening and diagnosis of gastric cancer (GC) in aim to support countries that do not have national guidelines on screening and diagnosis of GC. Current national or international guidelines were collected worldwide and recommendations were classified according to the quality of evidence and were finalized through a modified Delphi method. The minimum elements consist of seven categories: [1] Extraction of high-risk patients of GC before esophagogastroduodenoscopy (EGD), [2] Patients who need surveillance of GC, [3] Method to ensure quality of EGD for detection of GC, [4] Individual GC risk assessment by EGD, [5] Extraction of high-risk patients of GC after EGD [6] Qualitative or differential diagnosis of GC by EGD, and [7] Endoscopic assessment to choose the therapeutic strategy for GC. These minimum elements will be a guide to promote the elimination of GC among countries with a high incidence of GC who lack national guidelines or screening programs.

Comparison of the diagnostic efficacy of blue laser imaging with narrow band imaging for gastric cancer and precancerous lesions: a meta-analysis

BACKGROUND AND AIMS

novel endoscopic techniques including narrowband imaging (NBI) and blue laser imaging (BLI) have led to the improved detection of early stage gastric cancer and precancerous lesions. However, these techniques are not generally thought to be equivalent at present and BLI is generally considered as superior to NBI. Therefore, this comprehensive meta-analysis aimed to definitively compare the diagnostic efficacy of NBI and BLI for the diagnosis of gastric cancer and precancerous lesions.

METHODS

relevant articles were identified via searches of the PubMed, Web of Science, Embase and Cochrane Library databases from their inception until October 2019. In total, 28 relevant studies were identified and incorporated into the meta-analysis. RevMan5.3 was used to assess the relative diagnostic efficacy of these two imaging modalities in these studies. The threshold was assessed using Meta-DiSc 1.4 and STATA 14.0 for bivariate regression modeling of pooled studies.

RESULTS

the pooled sensitivity of BLI for gastric cancer was 0.89 (0.80, 0.95) and the specificity was 0.92 (0.76, 0.98). The pooled sensitivity of NBI for gastric cancer was 0.83 (0.75, 0.89) and the specificity was 0.95 (0.91, 0.97). The pooled sensitivity of BLI for precancerous lesions was 0.81 (0.71, 0.87) and the specificity was 0.90 (0.80, 0.96). The pooled sensitivity of NBI for precancerous lesions was 0.80 (0.75, 0.85) and the specificity was 0.88 (0.77, 0.94).

CONCLUSIONS

this study showed that both BLI and NBI have a very high diagnostic efficacy for the detection of gastric cancer and precancerous lesions, the sensitivity and specificity of these two approaches were similar.

Identifying early gastric cancer under magnifying narrow-band images with deep learning: a multicenter study

BACKGROUND AND AIMS

Narrow-band imaging with magnifying endoscopy (ME-NBI) has shown advantages in the diagnosis of early gastric cancer (EGC). However, proficiency in diagnostic algorithms requires substantial expertise and experience. In this study, we aimed to develop a computer-aided diagnostic model for EGM (EGCM) to analyze and assist in the diagnosis of EGC under ME-NBI.

METHODS

A total of 1777 ME-NBI images from 295 cases were collected from 3 centers. These cases were randomly divided into a training cohort (n = 170), an internal test cohort (ITC, n = 73), and an external test cohort (ETC, n = 52). EGCM based on VGG-19 architecture (Visual Geometry Group [VGG], Oxford University, Oxford, UK) with a single fully connected 2-classification layer was developed through fine-tuning and validated on all cohorts. Furthermore, we compared the model with 8 endoscopists with varying experience. Primary comparison measures included accuracy, area under the receiver operating characteristic curve (AUC), sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV).

RESULTS

EGCM acquired AUCs of .808 in the ITC and .813 in the ETC. Moreover, EGCM achieved similar predictive performance as the senior endoscopists (accuracy: .770 vs .755, P = .355; sensitivity: .792 vs .767, P = .183; specificity: .745 vs .742, P = .931) but better than the junior endoscopists (accuracy: .770 vs .728, P < .05). After referring to the results of EGCM, the average diagnostic ability of the endoscopists was significantly improved in terms of accuracy, sensitivity, PPV, and NPV (P < .05).

CONCLUSIONS

EGCM exhibited comparable performance with senior endoscopists in the diagnosis of EGC and showed the potential value in aiding and improving the diagnosis of EGC by endoscopists.

Magnifying endoscopy in detecting early gastric cancer: A network meta-analysis of prospective studies

BACKGROUND

Conventional white-light imaging endoscopy (C-WLI) had a significant number of misdiagnosis in early gastric cancer (EGC), and magnifying endoscopy (ME) combined with different optical imaging was more accurate in the diagnosis of EGC. This study aimed to evaluate the accuracy of ME and compare the accuracy of ME with different optical imaging in detecting EGC.

METHODS

A comprehensive literature search was conducted to identify all relevant studies. Pair-wise meta-analysis was conducted to evaluate the accuracy of ME, and Bayesian network meta-analysis was performed to combine direct and indirect evidence and estimate the relative effects.

RESULTS

Eight prospective studies were identified with a total of 5948 patients and 3 optical imaging in ME (ME with WLI (M-WLI), ME with narrow-band imaging (M-NBI), and ME with blue laser imaging (M-BLI)). Pair-wise meta-analysis showed a higher accuracy of ME than C-WLI (OR: 2.97, 95% CI: 1.68∼5.25). In network meta-analysis, both M-NBI and M-BLI were more accurate than M-WLI (OR: 2.56, 95% CI: 2.13∼3.13; OR: 3.13, 95% CI: 1.85∼5.71). There was no significant difference between M-NBI and M-BLI.

CONCLUSION

ME was effective in improving the detecting rate of EGC, especially with NBI or BLI.

Near-focus magnification and second-generation narrow-band imaging for early gastric cancer in a randomized trial

BACKGROUND

Magnifying endoscopy with narrow-band imaging (NBI) is effective for the diagnosis of early gastric cancer (EGC). However, magnifying endoscopy is not yet popular globally because of the required level of skill and lack of availability. To overcome these problems, dual-focus endoscopy (standard- and near-focus (NF) modes) has been developed. In this study, we evaluated the diagnostic performance of NF with second-generation (2G)-NBI (NF-NBI) for the diagnosis of EGC.

METHODS

This was a secondary analysis of a multicenter randomized controlled trial of 4523 high-risk patients who underwent gastroscopies at 13 institutions in Japan. Patients were randomly assigned to white-light imaging (WLI) followed by 2G-NBI or to 2G-NBI followed by WLI. Lesions suspicious for EGC, newly detected by non-magnifying WLI or 2G-NBI, were subsequently observed with NF-NBI. All detected lesions were biopsied or resected. The diagnostic performance of NF-NBI was compared with the final histology.

RESULTS

A total of 870 detected lesions (145 EGC, 725 non-EGC) were analyzed. Overall diagnostic performance for EGC using NF-NBI was accuracy 87.7%, sensitivity 60.7%, specificity 93.1%, positive predictive value 63.8%, and negative predictive value 92.2%. There were no significant differences in diagnostic performance between lesions detected by WLI or 2G-NBI. For lesions diagnosed with high (333 lesions) and low (537 lesions) confidences, accuracy was 92.2% and 84.9%, sensitivity was 64.7% and 58.5%, and specificity was 90.5% and 88.8%, respectively.

CONCLUSION

The diagnostic performance of NF-NBI is good and acceptable for diagnosis of EGC in combination with either WLI or 2G-NBI.

Image-enhanced endoscopy for gastric preneoplastic conditions and neoplastic lesions: a systematic review and meta-analysis

BACKGROUND : Image-enhanced endoscopy (IEE) improves the accuracy of endoscopic diagnosis. We aimed to assess the value of IEE for gastric preneoplastic conditions and neoplastic lesions. METHODS : Medline and Embase were searched until December 2018. Studies allowing calculation of diagnostic measures were included. Risk of bias and applicability were assessed using QUADAS-2. Subgroup analysis was performed to explore heterogeneity. RESULTS : 44 studies met the inclusion criteria. For gastric intestinal metaplasia (GIM), narrow-band imaging (NBI) obtained a pooled sensitivity and specificity of 0.79 (95 %CI 0.72-0.85) and 0.91 (95 %CI 0.88-0.94) on per-patient basis; on per-biopsy basis, it was 0.84 (95 %CI 0.81-0.86) and 0.95 (95 %CI 0.94-0.96), respectively. Tubulovillous pattern was the most accurate marker to detect GIM and it was effectively assessed without high magnification. For dysplasia, NBI showed a pooled sensitivity and specificity of 0.87 (95 %CI 0.84-0.89) and 0.97 (95 %CI 0.97-0.98) on per-biopsy basis. The use of magnification improved the performance of NBI to characterize early gastric cancer (EGC), especially when the vessel plus surface (VS) classification was applied. Regarding other technologies, trimodal imaging also obtained a high accuracy for dysplasia (sensitivity 0.93 [95 %CI 0.85-0.98], specificity 0.98 [95 %CI 0.92-1.00]). For atrophic gastritis, no specific pattern was noted and none of the technologies reached good diagnostic yield. CONCLUSION : NBI is highly accurate for GIM and dysplasia. The presence of tubulovillous pattern and the VS classification seem to be useful to detect GIM and characterize EGC, respectively. These features should be used in current practice and to standardize endoscopic criteria for other technologies.

Endoscopic acanthosis nigricans appearance: A novel specific marker for diagnosis of low-grade intraepithelial neoplasia

BACKGROUND AND AIM

At present, there is no recognized diagnostic criteria for gastric low-grade intraepithelial neoplasia (LGIN). The purpose of this study was to determine whether an "endoscopic acanthosis nigricans appearance (EANA)" could be a useful endoscopic marker for distinguishing LGIN lesions from peripheral non-neoplastic tissues.

METHODS

A retrospective study was conducted on 638 cases of suspected superficial lesions with endoscopic images from white light endoscopy and magnifying endoscopy combined with narrow band imaging. According to the pathological results of accurate biopsies, those lesions were divided into three groups: a control group, an LGIN group, and an early gastric cancer (EGC) group.

RESULTS

According to the presence of EANAs, the sensitivity, specificity, positive predictive value, and negative predictive value for differentiating between the LGIN and control groups were 24.8%, 97.3%, 78.3%, and 76.6%, respectively. The sensitivity (84.1%) and negative predictive value (92.4%) were significantly improved by combining EANA with types IV-VI pit pattern. The intervening part and mean gray value of glands, representing microsurface features and microvascular variation, were significantly larger or higher in EANA lesions than in the surrounding non-neoplastic mucosa. LGIN with EANA was more likely to be present in lesions of type 0-IIa. In addition, the prevalence of EANAs in EGC was 16.7%.

CONCLUSION

An EANA could be used as an auxiliary indicator for a diagnosis of LGIN in suspected lesions. It could also play a potential assistive role in the diagnosis of EGC lesions.

The accuracy of magnifying narrow band imaging (ME-NBI) in distinguishing between cancerous and noncancerous gastric lesions: A meta-analysis

BACKGROUND

Previous clinical trials have demonstrated the diagnostic accuracy of magnifying narrow-band (ME-NBI) for gastric cancerous lesions, but the results are inconsistent. The purpose of this meta-analysis is to investigate the accuracy of ME-NBI in distinguishing between cancerous and noncancerous gastric lesions.

METHODS

Systematic literature searches were conducted until October 2016 in PubMed, Embase by 2 independent reviewers. Meta-analysis was performed to calculate the pooled sensitivity, specificity. Two authors independently evaluated studies for inclusion, rated methodological quality, and abstracted relevant data. Meta-analytic method was used to construct summary receiver operating characteristic curves, and pooled sensitivity, specificity were calculated.

RESULTS

Nine studies enrolling 5398 lesions were included. The pooled sensitivity, specificity were 88% (95% confidence interval [CI]: 78-93%), 96% (95% CI: 91-98%), respectively. The area under the curve (AUC) was 0.97. There was a large heterogeneity between the included studies. Studies with lesions ≤ 10 mm still had a high pooled sensitivity of 81% (95% CI: 73-90%) and specificity of 97% (95% CI: 95-100%). Studies which analyzed resected specimens had a sensitivity of 91% (95 CI: 82-99%) and specificity of 88% (95% CI: 83-94%), and studies which analyzed biopsied specimens had a sensitivity of 85% (95 CI: 74-96%) and specificity of 99% (95% CI: 98-99%).

CONCLUSIONS

ME-NBI is highly accurate and consistent to distinguish between gastric cancerous and noncancerous lesions.

Comparison of the safety of the application of painless gastroscopy and ordinary gastroscopy in chronic hypertension patients combined with early gastric cancer

The aim of the present study was to compare the safety of the application of painless gastroscopy and ordinary gastroscopy for chronic hypertension patients combined with early gastric cancer. A total of 123 patients with early gastric cancer were selected at the Dongying People's Hospital from June, 2014 to August, 2016. The patients were randomly divided into the painless (n=63) and ordinary (n=60) gastroscopy groups. Proper pretreatment was performed according to whether anesthesia was performed or not. Arterial pressure, heart rate, and blood oxygen saturation were detected and compared before anesthesia, when gastroscope passed through the esophageal entrance plane, and after recovery from anesthesia. The incidence of nausea and vomiting, cough, dysphoria, throat discomfort and other adverse reactions during and after surgery were recorded and compared. Compared with the levels before anesthesia, the mean arterial pressure, heart rate and blood oxygen saturation were significantly reduced in painless gastroscopy when the gastroscope passed through the esophageal entrance plane (P<0.05). In the ordinary gastroscopy group, the mean arterial pressure, heart rate and blood oxygen saturation were significantly increased when the gastroscope passed through the esophageal entrance plane compared with the levels before anesthesia (P<0.05). Blood pressure decreased in the painless gastroscopy group whereas it increased in the ordinary gastroscopy group after anesthesia. The decrease in the painless gastroscopy group was lower than in the ordinary group. The incidence of intraoperative and postoperative adverse reactions including nausea, vomiting, cough, dysphoria, pharyngeal discomfort and other adverse reactions was significantly decreased in the painless gastroscopy group than in the ordinary gastroscopy group (P<0.05). The results suggest that the application of painless gastroscopy in chronic hypertension patients can significantly reduce the incidence of intraoperative and postoperative adverse reactions compared with that of the Gastric cancer ordinary gastroscopy. Thus, painless gastroscopy is safer than ordinary gastroscopy.

Past and current trends in endoscopic diagnosis for early stage gastric cancer in Japan

Methodology for the diagnosis and staging of early gastric cancer (EGC) has improved in Japan since the development of the gastro-camera and determination of a definition of EGC. Imaging technology has been steadily evolving in the endoscopy field. Improvements in the resolution of standard endoscopy images used in screening and surveillance provide greater opportunities to find gastric cancer earlier. Image enhancement endoscopy (IEE), such as narrow band imaging (NBI), highlights mucosal structures and vascularity. In particular, when NBI is used with magnifying endoscopy, it reveals fine details of subtle superficial abnormalities of EGC that are difficult to recognize using standard white light endoscopy. IEE-assisted magnifying endoscopy has improved the accuracy of the differentiation of superficial gastric cancer as well as delineation of the diseased mucosa. The advanced imaging technology enables precise assessment of the risk of lymph node metastasis of EGC and is widely used to determine indications for endoscopic treatment. It is not an overstatement to say that this has become the basis for the current development and dissemination of endoscopic treatments. Moreover, the resolution of endoscopic imaging has been upgraded to the microscopy level by the development of endomicroscopy, including endocytoscopy and confocal laser endomicroscopy. Endomicroscopy allows real-time histological analysis of living tissue during routine endoscopy and may reduce the number of biopsies needed to reach the correct diagnosis, minimizing the risk of sampling errors.

Diagnostic Performance of Narrow Band Imaging for Laryngeal Cancer: A Systematic Review and Meta-analysis

Objective

To evaluate the performance of narrow band imaging (NBI) for the diagnosis of laryngeal cancer and to compare the diagnostic value of NBI with that of white light endoscopy.

Data Sources

PubMed, Embase, Cochrane Library, and CNKI databases.

Review Methods

Data analyses were performed with Meta-DiSc. The updated Quality Assessment of Diagnostic Accuracy Studies–2 tool was used to assess study quality and potential bias. Publication bias was assessed with the Deeks’s asymmetry test. The protocol used in this article has been published on PROSPERO and is in accordance with the PRISMA checklist. The registry number for this study is CRD42015025866.

Results

Six studies including 716 lesions were included in this meta-analysis. The pooled sensitivity, specificity, and diagnostic odds ratio for the NBI diagnosis of laryngeal cancer were 0.94 (95% confidence interval [95% CI]: 0.91-0.96), 0.89 (95% CI: 0.85-0.92), and 142.12 (95% CI: 46.42-435.15), respectively, and the area under receiver operating characteristics curve was 0.97. Among the 6 studies, 3 evaluated the diagnostic value of white light endoscopy, with a sensitivity of 0.81 (95% CI: 0.76-0.86), a specificity of 0.92 (95% CI: 0.88-0.95), and a diagnostic odds ratio of 33.82 (95% CI: 14.76-77.49). The evaluation of heterogeneity, calculated per the diagnostic odds ratio, gave an I2 of 66%. No marked publication bias ( P = .84) was detected in this meta-analysis.

Conclusion

The sensitivity of NBI is superior to white light endoscopy, and the potential value of NBI needs to be validated in future studies.

Acetic acid chromoendoscopy for determining the extent of gastric intestinal metaplasia

BACKGROUND AND AIMS

The diagnosis of gastric intestinal metaplasia (IM) is currently performed by histologic assessment of multiple endoscopic biopsies, methylene blue chromoendoscopy, or narrow-band imaging with magnification. However, practical and readily available methods are lacking. We assessed the diagnostic accuracy and reproducibility of acetic acid chromoendoscopy (AAC) for determining the extent of gastric IM.

METHODS

One hundred twenty-six participants were enrolled. The participants underwent screening EGD with 1.5% acetic acid instillation for the detection of acetowhite reaction. Subsequently, targeted biopsies were performed at the 5 standard intra-gastric locations of the updated Sydney system. The accuracy of AAC was calculated using the histology results as a reference. Two endoscopists, each of whom was blinded to the other's result, determined the presence or absence of acetowhite reaction.

RESULTS

The overall diagnostic accuracy of AAC was 89.0%, and the sensitivity and specificity were 77.6% and 94.4%, respectively. The specificity for the gastric body was >94%. The proportion of extensive IM, a strong risk factor for gastric cancer, increased from 0.9% to 18.1% when AAC was used instead of conventional EGD alone (P < .001). Endoscopically determined atrophy had a negative effect on the diagnosis of AAC (odds ratio, 3.012; 95% confidence interval, 1.625-5.583). There was substantial inter- and intra-observer agreement.

CONCLUSIONS

AAC is a valid and reproducible tool for determining the extent of gastric IM and may serve as a practical method of identifying populations at high risk of gastric cancer. (Clinical trial registration number: NCT01499576.).

Acetic Acid Enhanced Narrow Band Imaging for the Diagnosis of Gastric Intestinal Metaplasia

Gastric intestinal metaplasia (GIM) is a precancerous lesion of the stomach. The detection of GIM using conventional white-light endoscopy (WLE) is difficult. In this study, we determined whether acetic acid-enhanced narrow band imaging (AA-NBI) improves the detection of GIM. A consecutive cohort of 132 individuals aged 40 years or older was subjected to upper gastrointestinal endoscopy using WLE, NBI and AA-NBI. The ability of the three methods to diagnose GIM in patients was compared. Histological assessment (per-patient and per-biopsy) was used for the accuracy assessment. Sixty-six (50.0%) out of the 132 individuals examined were found to have GIM, of which 44 (66.7%) were diagnosed correctly by NBI (sensitivity 66.7% and specificity 68.2%) and 58 (87.9%) were correctly identified by AA–NBI (sensitivity 87.9% and specificity 68.2%), as compared to only 22 (33.3%) by WLE (sensitivity 33.3% and specificity 28.8%). Therefore, the sensitivity of AA–NBI in the diagnosis of GIM was significantly higher than NBI (p<0.05) and WLE (p < 0.001). Our study indicates that AA-NBI can improve the accuracy of endoscopy-targeted biopsies for GIM.

Combined optical coherence tomography and hyperspectral imaging using a double-clad fiber coupler

This work demonstrates the combination of optical coherence tomography (OCT) and hyperspectral imaging (HSI) using a double-clad optical fiber coupler. The single-mode core of the fiber is used for OCT imaging, while the inner cladding of the double-clad fiber provides an efficient way to capture the reflectance spectrum of the sample. The combination of both methods enables three-dimensional acquisition of the sample morphology with OCT, enhanced with complementary molecular information contained in the hyperspectral image. The HSI data can be used to highlight the presence of specific molecules with characteristic absorption peaks or to produce true color images overlaid on the OCT volume for improved tissue identification by the clinician. Such a system could be implemented in a number of clinical endoscopic applications and could improve the current practice in tissue characterization, diagnosis, and surgical guidance.

Can magnifying endoscopy with narrow-band imaging discriminate between carcinomas and low grade adenomas in gastric superficial elevated lesions?

Background and study aims: The aim of this study was to investigate the capability of magnifying endoscopy with narrow-band imaging (ME-NBI) to discriminate between early carcinomas (EC) and low grade adenomas (LGA) in gastric superficial elevated epithelial neoplasias. Patients and methods: We investigated 100 consecutive cases of gastric superficial elevated epithelial neoplasias that were removed using endoscopic submucosal dissection. The pathological diagnostic criteria were based on the revised Vienna classification; category 4 (mucosal high grade neoplasia) and category 5 (submucosal invasion by carcinoma) lesions were diagnosed as EC, whereas category 3 (mucosal low grade neoplasia) lesions were diagnosed as LGA. The associations between the postoperative pathological diagnoses and the ME-NBI findings were analyzed, and included the shape, specification, and area of irregularity in the microvascular architecture (MV) and the microsurface structure (MS). Results: Seventy-nine EC and 21 LGA cases diagnosed postoperatively were evaluated retrospectively. The lesion size (median; range (mm)) was significantly larger in the EC group (14; 2 - 95) compared to the LGA group (5; 2 - 16) (P < 0.001). Wavy forms in the MV shapes (P = 0.031), extension in the MV specifications (P = 0.035), and area with MV irregularity (P = 0.001) were found to be statistically significant predictive findings for EC. Villous forms in the MS shapes (P = 0.026), enlargement in the MS specifications (P = 0.044), and area with MS irregularity (P = 0.021) were also found to be statistically significant predictive findings for EC. The rates of preoperative sensitivity, specificity, and diagnostic accuracy of ME-NBI for discriminating EC were 86.1 %, 38.9 %, and 75 %, respectively. Conclusions: The present study suggests that ME-NBI is useful for the differential diagnosis of EC and LGA in gastric superficial elevated epithelial neoplasias.

STUDY REGISTRATION

UMIN000012925.

How to improve endoscopic diagnosis of early gastric cancer?

Gastric cancer is the third leading cause of cancer death worldwide. The detection of early-stage gastric neoplastic lesions may improve survival. The gold standard for diagnosing gastric cancer remains endoscopy and histology of biopsy specimens. On one hand, we should administer the optimum preparation to patients, including an antiperistaltic agent. On the other hand, in order to detect the entire stomach, we need to follow a standardized protocol, and we should be aware of the diagnostic criteria for a suspicious lesion. Chromoendoscopy, narrow band imaging and magnifying endoscopy are promising image-enhanced endoscopic techniques for characterization. The criteria for diagnosing a cancerous lesion by narrow-band imaging with magnifying endoscopy are as follows: irregular microvascular pattern with a demarcation line or irregular microsurface pattern with a demarcation line. This paper gives a brief review of these methods.

Risk Stratification According to the Total Number of Factors That Meet the Indication Criteria for Radical Lymph Node Dissection in Patients with Early Gastric Cancer at Risk for Lymph Node Metastasis

BACKGROUND

Extended indications for endoscopic resection for early gastric cancer (EGC) have been widely accepted. However, according to current guidelines, additional gastrectomy with lymph node dissection (LND) is recommended for patients proven to have potential risks of lymph node metastasis (LNM) on histopathological findings. The aim of this study was to elucidate the risk stratification of outcome and LNM according to the number of factors that meet the inclusion criteria for radical LND for possible LNM (LNM risk factors) in patients with negative endoscopic resection margin.

METHODS

We enrolled 511 EGC patients whose tumors did not meet the absolute or extended indications for endoscopic resection, and investigated the risk stratification of prognosis and LNM according to the total number of LNM risk factors.

RESULTS

Recurrence-free and overall survival rates were significantly higher in patients with fewer LNM risk factors for surgical indication (p = 0.0274 and 0.0002, respectively; log-rank test), and the total number of LNM risk factors and frequency of LNM were significantly correlated (p < 0.0001; Kruskal-Wallis test). When only one LNM risk factor was satisfied, the LNM ratio was 0.58 % (1/173, 95 % confidence interval 0.01-3.18).

CONCLUSION

The present study suggested the possibility of using further minimally invasive treatment strategies based on the total number of LNM risk factors.

Useful condition of chromoendoscopy with indigo carmine and acetic acid for identifying a demarcation line prior to endoscopic submucosal dissection for early gastric cancer

Background

Identifying a precise demarcation line (DL) is indispensable for pathological complete en bloc endoscopic submucosal dissection (ESD) for early gastric cancer (EGC). We evaluated the useful condition of chromoendoscopy with indigo carmine and acetic acid for marking dots around lesions before ESD for EGC.

Methods

We examined 98 consecutive patients with 109 intramucosal EGCs (mean diameter, 17.8 ± 12.4 mm; main histologic type, 96 intestinal and 13 diffuse) resected by en bloc ESD after chromoendoscopy with indigo carmine and acetic acid between December 2012 and February 2014. The DL was identified by this technique just before ESD (mean chromoendoscopy observation time, 71.6 s); subsequently, marking dots were placed around the EGC. EGCs were classified into two groups: useful for identifying the DL or useless. Clinicopathological characteristics and clinical outcomes were evaluated in each group.

Results

Forty-two of the 109 cases (38.5 %) were determined useful for chromoendoscopy with indigo carmine and acetic acid. Multivariate analysis with logistic regression showed that macroscopic type (protruded or flat elevated-type) and atrophic border (the oral side of tumor) were independently associated with the usefulness of chromoendoscopy using indigo carmine and acetic acid for identifying the DL of EGCs (P < 0.05). The histologically positive horizontal margin after ESD was 0 % (0/42) in useful cases, and 7.5 % (5/67) in useless cases.

Conclusions

Before ESD, chromoendoscopy with indigo carmine and acetic acid can be used for creating precise markings in protruded or flat elevated-type EGC or at the atrophic border on the oral side of EGCs.

Magnifying endoscopy simple diagnostic algorithm for early gastric cancer (MESDA-G)

Gastric cancer is the third leading cause of cancer death worldwide. Early detection and accurate diagnosis of mucosal cancer is desirable in order to achieve decreased mortality; cause-specific survival of patients with early gastric cancer is reported to exceed 95%. Endoscopy is the functional modality to detect early cancer; however, the procedure is not definitive when using conventional white-light imaging. In contrast, magnifying narrow-band imaging (M-NBI), a novel endoscopic technology, is a powerful tool for characterizing gastric mucosal lesions because it can visualize the microvascular architecture and microsurface structure. To date, many reports on the diagnosis of early gastric cancer by M-NBI, including multicenter prospective randomized studies conducted in Japan, have been published in peer-reviewed international journals. Based on these published data, we devised a proposal for a diagnostic strategy for gastric mucosal cancer using M-NBI to simplify the process of diagnosis and improve accuracy. Herein, we recommend a diagnostic algorithm for early gastric cancer using magnifying endoscopy.

Comparison of the diagnostic efficacy of white light endoscopy and magnifying endoscopy with narrow band imaging for early gastric cancer: a meta-analysis

OBJECTIVE

Magnifying endoscopy with narrow band imaging (ME-NBI) is widely used in gastroscopy, especially in the diagnosis of early gastric cancer. The purpose of this meta-analysis is to compare the diagnostic efficacy of white light imaging (WLI) and that of ME-NBI for early gastric cancer.

METHODS

PubMed/MEDLINE, EMBASE, and the Cochrane Library were searched to identify studies which met the inclusion criteria. A random-effects model was used to calculate overall sensitivity, specificity, and the area under the receiver operating characteristic curve (AUC) to assess the diagnostic efficacy of WLI and ME-NBI in early gastric cancer. Sensitivity analysis was performed to assess the stability of the results.

RESULTS

Ten studies met the inclusion criteria, and included 1724 patients and 2153 lesions. The pooled sensitivity, specificity, and AUC for the diagnosis of early gastric cancer using WLI were 0.48 [95 % confidence interval (CI) 0.39-0.57; I (2) = 78.6 %], 0.67 (95 % CI 0.62-0.71; I (2) = 81.9 %), and 0.62, respectively. The pooled sensitivity, specificity, and AUC using ME-NBI were 0.83 (95 % CI 0.79-0.87; I (2) = 79.8 %), 0.96 (95 % CI 0.95-0.97; I (2) = 89.3 %), and 0.96, respectively. The studies showed a high degree of heterogeneity. Further sensitivity analysis was mainly performed for the studies of small lesions (mean size 10 mm or less) and the studies with a the score of 12 points or greater in the literature quality assessment, and the AUCs for ME-NBI for diagnosis of early gastric cancer were between 0.93 and 0.98, which suggested that the diagnostic value was still high and stable.

CONCLUSION

Compared with WLI, ME-NBI can effectively diagnose early gastric cancer.

Clinical Application of Magnifying Endoscopy with Narrow-Band Imaging in the Stomach

Magnifying endoscopy with narrow-band imaging (M-NBI) can visualize superficial microanatomies in the stomach. The normal morphology of the microanatomy visualized by M-NBI differs according to the part of the stomach. The gastric fundic glandular mucosa appears as a regular honeycomb-like subepithelial capillary network (SECN) pattern with a regular collecting venule pattern and regular oval crypt opening with circular marginal crypt epithelium (MCE) pattern. The gastric pyloric glandular mucosa displays a regular coil-shaped SECN pattern and regular polygonal or curved MCE pattern. For a diagnosis of early gastric cancer using M-NBI, the vessel plus surface classification system was developed. This system is clinically useful for the differential diagnosis of focal gastritis and small depressed cancer and for determining the horizontal extent of early gastric cancer for successful endoscopic resection. Advantages of M-NBI over conventional endoscopic imaging techniques with white light include accurate diagnosis and cost effectiveness. This technique is a breakthrough in the endoscopic diagnostic field.

Comparison between narrow-band imaging combined with magnifying endoscopy and gastric biopsy for diagnosis of early gastric cancer

AIM: To evaluate the diagnostic performance of narrow-band imaging combined with magnifying endoscopy (NBI-ME) for early gastric cancer by comparing with gastric biopsy.

METHODS: Patients with suspicious early gastric lesions (including abnormal mucosal morphology and abnormal mucosal color) as revealed by white light endoscopy (WLE) were enrolled in the study. These suspicious lesions were examined by NBI-ME to give a diagnosis. Biopsy specimens were then taken from suspicious lesions for pathological examination. All patients received endoscopic resection or surgical intervention. The diagnostic performance of the two modalities was compared.

RESULTS: A total of 123 patients were enrolled, including 76 men and 47 women. The final pathology showed 51 cases of gastritis, 24 cases of low grade intraepithelial neoplasia, and 48 cases of early gastric cancer. The sensitivity, specificity, positive predictive value, negative predictive value and accuracy of NBI-ME for diagnosing early gastric cancer were 97.9%, 80.0%, 75.8%, 98.4%, and 87.0%, respectively; the corresponding percentages for endoscopic biopsy were 66.7%, 94.7%, 88.9%, 81.6%, and 83.7%, respectively. The sensitivity of NBI-ME was significantly better than that of endoscopic biopsy (P < 0.005), but specificity was lower than that of endoscopic biopsy (P < 0.005). There was no statistical difference in diagnostic accuracy between the two modalities. The Kappa value for the two modalities was 0.642 (P < 0.05).

CONCLUSION: NBI-ME can improve the diagnosis of early gastric cancer. When early gastric cancer is diagnosed by NBI-ME, further intervention treatment is required.

Magnifying narrow-band imaging endoscopy is superior in diagnosis of early gastric cancer

AIM: To evaluate the diagnostic effectiveness of white light endoscopy, magnifying endoscopy (ME), and magnifying narrow-band imaging endoscopy (ME-NBI) in detecting early gastric cancer (EGC).

METHODS: From March 2010 to June 2012, a total of 3616 patients received screening for gastric cancer by magnifying endoscopy. There were 3675 focal gastric lesions detected using conventional high definition white light endoscopy (HD-WLE) in four different referential hospitals that were recruited for further investigation using ME and ME-NBI. The images obtained from HD-WLE, ME, and ME-NBI were reviewed by four experienced endoscopists to evaluate their diagnostic effectiveness for EGC. The diagnosis of cancerous and non-cancerous lesions was conducted by evaluating the microvascular and microsurface patterns using the VS classification system. The final endoscopic diagnosis of each lesion was determined by consultation when a disagreement occurred. We used histopathological results as the gold standard for the diagnosis of EGC.

RESULTS: Among the 3675 lesions found, 1508 were validated by pathological findings as chronic gastritis, 1279 as chronic gastritis with intestinal metaplasia, 631 as low-grade neoplasia, and 257 as EGC. The sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of HD-WLE for the diagnosis of EGC were 71.2%, 99.1%, 85.5%, 97.9% and 97.1%, respectively. The results of ME for diagnosing EGC were 81.3%, 98.8%, 83.3%, 98.6% and 97.6%, respectively. The results of ME-NBI for the diagnosis of EGC were 87.2%, 98.6%, 82.1%, 99.0% and 97.8%, respectively. The diagnostic sensitivity and accuracy of paired ME and ME-NBI were significantly better than those of HD-WLE (P < 0.05).

CONCLUSION: HD-WLE has a relatively high accuracy for diagnosing EGC and is an effective screening tool. Further investigations of ME and ME-NBI are required to achieve superior accuracy.

Diagnostic performance of magnifying narrow-band imaging for early gastric cancer: A meta-analysis

AIM: To investigate the performance of magnifying endoscopy with narrow-band imaging (ME-NBI) in the diagnosis of early gastric cancer (EGC).

METHODS: Systematic literature searches were conducted until February 2014 in PubMed, EMBASE, Web of Science, Ovid, Scopus and the Cochrane Library databases by two independent reviewers. Meta-analysis was performed to calculate the pooled sensitivity, specificity and diagnostic odds ratio and to construct a summary receiver operating characteristic (ROC) curve. Subgroup analyses were performed based on the morphology type of lesions, diagnostic standard, the size of lesions, type of assessment, country and sample size to explore possible sources of heterogeneity. A Deeks’ asymmetry test was used to evaluate the publication bias.

RESULTS: Fourteen studies enrolling 2171 patients were included. The pooled sensitivity, specificity and diagnostic odds ratio for ME-NBI diagnosis of EGC were 0.86 (95%CI: 0.83-0.89), 0.96 (95%CI: 0.95-0.97) and 102.75 (95%CI: 48.14-219.32), respectively, with the area under ROC curve being 0.9623. Among the 14 studies, six also evaluated the diagnostic value of conventional white-light imaging, with a sensitivity of 0.57 (95%CI: 0.50-0.64) and a specificity of 0.79 (95%CI: 0.76-0.81). When using “VS” (vessel plus surface) ME-NBI diagnostic systems in gastric lesions of depressed macroscopic type, the pooled sensitivity and specificity were 0.64 (95%CI: 0.52-0.75) and 0.96 (95%CI: 0.95-0.98). For the lesions with a diameter less than 10 mm, the sensitivity and specificity were 0.74 (95%CI: 0.65-0.82) and 0.98 (95%CI: 0.97-0.98).

CONCLUSION: ME-NBI is a promising endoscopic tool in the diagnosis of early gastric cancer and might be helpful in further target biopsy.

Diagnostic efficacy of magnifying endoscopy with narrow-band imaging for gastric neoplasms: a meta-analysis

Background

Magnifying endoscopy with narrow-band imaging (ME-NBI) is a novel, image-enhanced endoscopic technique for differentiating gastrointestinal neoplasms and potentially enabling pathological diagnosis.

Objectives

The aim of this analysis was to assess the diagnostic performance of ME-NBI for gastric neoplasms.

Methods

We performed a systematic search of the PubMed, EMbase, Web of Science, and Cochrane Library databases for relevant studies. Meta-DiSc (version 1.4) and STATA (version 11.0) software were used for the data analysis. Random effects models were used to assess diagnostic efficacy. Heterogeneity was tested by the Q statistic and I² statistic. Meta-regression was used to analyze the sources of heterogeneity.

Results

A total of 10 studies, with 2151 lesions, were included. The pooled characteristics of these studies were as follows: sensitivity 0.85 (95% confidence interval [CI]: 0.81–0.89), specificity 0.96 (95% confidence interval [CI]: 0.95–0.97), and area under the curve (AUC) 0.9647. In the subgroup analysis, which compared the diagnostic efficacy of ME-NBI and white light imaging (WLI), the pooled sensitivity and specificity of ME-NBI were 0.87 (95% CI: 0.80–0.92) and 0.93 (95% CI: 0.90–0.95), respectively, and the area under the curve (AUC) was 0.9556. In contrast, the pooled sensitivity and specificity of WLI were 0.61 (95% CI: 0.53–0.69) and 0.65 (95% CI: 0.60–0.69), respectively, and the area under the curve (AUC) was 0.6772.

Conclusions

ME-NBI presents a high diagnostic value for gastric neoplasms and has a high specificity.

In vivo histopathology using endocytoscopy for non-neoplastic changes in the gastric mucosa: a prospective pilot study (with video)

BACKGROUND

Endocytoscopy (EC), as a novel ultrahigh magnification technology, enables in vivo histopathological diagnoses of the GI tract. EC is particularly exceptional when comparing dysplastic and neoplastic tissue with normal tissue. There are, however, no detailed data for minute or minimal changes in the gastric mucosa.

OBJECTIVE

To describe non-neoplastic EC patterns of the gastric mucosa correlated with histopathological findings and to determine any relationship with Helicobacter pylori (HP) infection.

DESIGN

A pilot prospective study.

SETTING

Tertiary care referral center.

PATIENTS

Sixty-four participants undergoing upper endoscopy for various indications.

METHODS

Antral mucosal patterns on EC were divided into 4 categories: type 1 (normal), each papilla/pit has round smooth structure; type 2 (gastritis), extended, notched, and distorted structure with some necrotic tissue; type 3(atrophy), neighboring papilla/pit take on a lobulated appearance; type 4 (intestinal metaplasia [IM]), goblet cells are identified in a completely stained crypt. Target biopsy specimens were obtained from the region identified with these patterns, and multiple HP tests were performed.

RESULTS

HP positivity was 0%, 40.9%, 50.0%, and 58.3% in types 1, 2, 3, and 4, respectively. The sensitivity and specificity of types 2+3+4 for HP positivity were 100％ and 42.5%, respectively. The positive predictive values of type 1 for normal, type 2 for chronic gastritis, type 3 for atrophic gastritis, and type 4 for IM were 100%, 62.5%, 40.0%, and 100%, respectively. The sensitivity and specificity of types 3+4 for atrophic gastritis to IM were 87.0% and 95.1%, respectively.

LIMITATIONS

Small, single-center, pilot study.

CONCLUSIONS

EC can differentiate gastric mucosal patterns of minimal, non-neoplastic change and appears to reliably exclude HP infection.

Diagnosis of early gastric cancer using narrow band imaging and acetic acid

AIM: To determine whether the endoscopic findings of depressed-type early gastric cancers (EGCs) could precisely predict the histological type.

METHODS: Ninety depressed-type EGCs in 72 patients were macroscopically and histologically identified. We evaluated the microvascular (MV) and mucosal surface (MS) patterns of depressed-type EGCs using magnifying endoscopy (ME) with narrow-band imaging (NBI) (NBI-ME) and ME enhanced by 1.5% acetic acid, respectively. First, depressed-type EGCs were classified according to MV pattern by NBI-ME. Subsequently, EGCs unclassified by MV pattern were classified according to MS pattern by enhanced ME (EME) images obtained from the same angle.

RESULTS: We classified the depressed-type EGCs into the following 2 MV patterns using NBI-ME: a fine-network pattern that indicated differentiated adenocarcinoma (25/25, 100%) and a corkscrew pattern that likely indicated undifferentiated adenocarcinoma (18/23, 78.3%). However, 42 of the 90 (46.7%) lesions could not be classified into MV patterns by NBI-ME. These unclassified lesions were then evaluated for MS patterns using EME, which classified 33 (81.0%) lesions as MS patterns, diagnosed as differentiated adenocarcinoma. As a result, 76 of the 90 (84.4%) lesions were matched with histological diagnoses using a combination of NBI-ME and EME.

CONCLUSION: A combination of NBI-ME and EME was useful in predicting the histological type of depressed-type EGC.

Diagnostic performance and limitations of magnifying narrow-band imaging in screening endoscopy of early gastric cancer: a prospective multicenter feasibility study

BACKGROUND

Curative treatment of patients with gastric cancer requires reliable detection of early gastric cancer. Magnifying endoscopy with narrow-band imaging (M-NBI) is useful for the accurate preoperative diagnosis of early gastric cancer. However, the role of M-NBI in screening endoscopy has not been established. The aims of this study were to determine the feasibility and limitations of M-NBI in screening endoscopy.

METHODS

We conducted a multicenter prospective uncontrolled trial of patients undergoing routine screening endoscopy patients. We determined the diagnostic accuracy, sensitivity and specificity of M-NBI according to the degree of certainty and need for biopsy, as assessed using the VS (vessel plus surface) classification system. We analyzed the endoscopic and histopathological characteristics of both false negative and false positive high confidence M-NBI diagnoses. We then developed a provisional diagnostic strategy based on the diagnostic performance and limitations identified in this study.

RESULTS

A total of 1097 patients were enrolled in the study. We analyzed 371 detected lesions (20 cancers and 351 non-cancers). The accuracy, sensitivity and specificity of high confidence M-NBI diagnoses were 98.1, 85.7 and 99.4 %, respectively. The false negative case was a pale mucosal lesion with tissue diagnosis of signet-ring cell carcinoma. Exclusion of pale mucosal lesions increased the accuracy, sensitivity and specificity of high confidence M-NBI diagnoses to 99.4, 100 and 99.4 %, respectively. We therefore propose a practical strategy targeting non-pale mucosal lesions.

CONCLUSIONS

With a refined strategy considering its limitations, M-NBI can act as an "optical biopsy" in screening endoscopies.

Assessment of still and moving images in the diagnosis of gastric lesions using magnifying narrow-band imaging in a prospective multicenter trial

Objectives

Magnifying narrow-band imaging (M-NBI) is more accurate than white-light imaging for diagnosing small gastric cancers. However, it is uncertain whether moving M-NBI images have additional effects in the diagnosis of gastric cancers compared with still images.

Design

A prospective multicenter cohort study.

Methods

To identify the additional benefits of moving M-NBI images by comparing the diagnostic accuracy of still images only with that of both still and moving images. Still and moving M-NBI images of 40 gastric lesions were obtained by an expert endoscopist prior to this prospective multicenter cohort study. Thirty-four endoscopists from ten different Japanese institutions participated in the prospective multicenter cohort study. Each study participant was first tested using only still M-NBI images (still image test), then tested 1 month later using both still and moving M-NBI images (moving image test). The main outcome was a difference in the diagnostic accuracy of cancerous versus noncancerous lesions between the still image test and the moving image test.

Results

Thirty-four endoscopists were analysed. There were no significant difference of cancerous versus noncancerous lesions between still and moving image tests in the diagnostic accuracy (59.9% versus 61.5%), sensitivity (53.4% versus 55.9%), and specificity (67.0% versus 67.6%). And there were no significant difference in the diagnostic accuracy between still and moving image tests of demarcation line (65.4% versus 65.5%), microvascular pattern (56.7% versus 56.9%), and microsurface pattern (48.1% versus 50.9%). Diagnostic accuracy showed no significant difference between the still and moving image tests in the subgroups of endoscopic findings of the lesions.

Conclusions

The addition of moving M-NBI images to still M-NBI images does not improve the diagnostic accuracy for gastric lesions. It is reasonable to concentrate on taking sharp still M-NBI images during endoscopic observation and use them for diagnosis.

Trial registration

Umin.ac.jp UMIN-CTR000008048