Zooming in on Barrett oesophagus using narrow-band imaging: an international observer agreement study

Deep Learning in Barrett's Esophagus Diagnosis: Current Status and Future Directions

Barrett's esophagus (BE) represents a pre-malignant condition characterized by abnormal cellular proliferation in the distal esophagus. A timely and accurate diagnosis of BE is imperative to prevent its progression to esophageal adenocarcinoma, a malignancy associated with a significantly reduced survival rate. In this digital age, deep learning (DL) has emerged as a powerful tool for medical image analysis and diagnostic applications, showcasing vast potential across various medical disciplines. In this comprehensive review, we meticulously assess 33 primary studies employing varied DL techniques, predominantly featuring convolutional neural networks (CNNs), for the diagnosis and understanding of BE. Our primary focus revolves around evaluating the current applications of DL in BE diagnosis, encompassing tasks such as image segmentation and classification, as well as their potential impact and implications in real-world clinical settings. While the applications of DL in BE diagnosis exhibit promising results, they are not without challenges, such as dataset issues and the "black box" nature of models. We discuss these challenges in the concluding section. Essentially, while DL holds tremendous potential to revolutionize BE diagnosis, addressing these challenges is paramount to harnessing its full capacity and ensuring its widespread application in clinical practice.

Computer-aided characterization of early cancer in Barrett's esophagus on i-scan magnification imaging: a multicenter international study

BACKGROUND AND AIMS

We aimed to develop a computer-aided characterization system that could support the diagnosis of dysplasia in Barrett's esophagus (BE) on magnification endoscopy.

METHODS

Videos were collected in high-definition magnification white-light and virtual chromoendoscopy with i-scan (Pentax Hoya, Japan) imaging in patients with dysplastic and nondysplastic BE (NDBE) from 4 centers. We trained a neural network with a Resnet101 architecture to classify frames as dysplastic or nondysplastic. The network was tested on 3 different scenarios: high-quality still images, all available video frames, and a selected sequence within each video.

RESULTS

Fifty-seven patients, each with videos of magnification areas of BE (34 dysplasia, 23 NDBE), were included. Performance was evaluated by a leave-1-patient-out cross-validation method. In all, 60,174 (39,347 dysplasia, 20,827 NDBE) magnification video frames were used to train the network. The testing set included 49,726 i-scan-3/optical enhancement magnification frames. On 350 high-quality still images, the network achieved a sensitivity of 94%, specificity of 86%, and area under the receiver operator curve (AUROC) of 96%. On all 49,726 available video frames, the network achieved a sensitivity of 92%, specificity of 82%, and AUROC of 95%. On a selected sequence of frames per case (total of 11,471 frames), we used an exponentially weighted moving average of classifications on consecutive frames to characterize dysplasia. The network achieved a sensitivity of 92%, specificity of 84%, and AUROC of 96%. The mean assessment speed per frame was 0.0135 seconds (SD ± 0.006).

CONCLUSION

Our network can characterize BE dysplasia with high accuracy and speed on high-quality magnification images and sequence of video frames, moving it toward real-time automated diagnosis.

Usefulness of the Japan Esophageal Society Classification of Barrett's Esophagus for Diagnosing the Lateral Extent of Superficial Short-Segment Barrett's Esophageal Cancer

Introduction

The Japanese guidelines for endoscopic submucosal dissection (ESD) of Barrett's esophageal adenocarcinoma (BEA) recommend image-enhanced magnifying endoscopic examination for diagnosing the lateral extent of superficial esophageal adenocarcinoma. The Japan Esophageal Society Barrett's Esophagus (JES-BE) classification is proposed recently and is useful in terms of diagnostic accuracy. In this study, we retrospectively examined the usefulness of the JES-BE classification for differential diagnosis and determination of the extent of BEA originating in short-segment Barrett's esophagus.

Methods

The study reviewed 51 lesions which underwent ESD for BEA. The circumference of the esophagogastric junction was divided into four parts, and the lesions were divided into those in the right anterior portion (RA group; n = 33) and those in other portions (non-RA group; n = 18). Clinicopathological characteristics and clinical outcomes were compared between the two groups.

Results

JES-BE classification findings as "dysplasia" were seen in 48 out of 51 (94.1%) BEA lesions retrospectively. There was no significant difference in histological type, tumor depth, lymphovascular invasion, or the proportion of tumors with a positive or unknown horizontal or vertical margin status between the groups. The proportion of tumors with type 0-I morphology was significantly higher in the RA group (p = 0.023). The tumor size was significantly greater in the RA group (p = 0.034). According to the JES-BE classification, 31 lesions (93.9%) in the RA group and 17 lesions (94.4%) in the non-RA group were diagnosed as dysplasia. There was also no significant difference in the rate of consistency between the endoscopic and histopathological findings on the lateral extent of the lesion (90.9% vs. 83.3%; p = 0.612).

Discussion/Conclusions

The JES-BE classification may be useful for determining the extent of BEA.

Diagnostic accuracy of narrow-band imaging endoscopy with targeted biopsies compared with standard endoscopy with random biopsies in patients with Barrett's esophagus: A systematic review and meta-analysis

BACKGROUND AND AIM

Endoscopic surveillance for dysplasia in Barrett's esophagus (BE) with random biopsies is the primary diagnostic tool for monitoring clinical progression into esophageal adenocarcinoma. As an alternative, narrow-band imaging (NBI) endoscopy offers targeted biopsies that can improve dysplasia detection. This study aimed to evaluate NBI-guided targeted biopsies' diagnostic accuracy for detecting dysplasia in patients undergoing endoscopic BE surveillance compared with the widely used Seattle protocol.

METHODS

Cochrane DTA Register, MEDLINE/PubMed, EMBASE, OpenGrey, and bibliographies of identified papers were searched until 2018. Two independent investigators resolved discrepancies by consensus, study selection, data extraction, and quality assessment. Data on sensitivity, specificity, and predictive values were pooled and analyzed using a random-effects model.

RESULTS

Of 9528 identified articles, six studies comprising 493 participants were eligible for quantitative synthesis. NBI-targeted biopsy showed high diagnostic accuracy in detection of dysplasia in BE with a sensitivity of 76% (95% confidence interval [CI]: 0.61-0.91), specificity of 99% (95% CI: 0.99-1.00), positive predictive value of 97% (95% CI: 0.96-0.99), and negative predictive value of 84% (95% CI: 0.69-0.99) for detection of all grades of dysplasia. The receiver-operating characteristic curve for NBI model performance was 0.8550 for detecting all dysplasia.

CONCLUSION

Narrow-band imaging-guided biopsy demonstrated high diagnostic accuracy and might constitute a valid substitute for random biopsies during endoscopic surveillance for dysplasia in BE.

Barrett's Esophagus and Intestinal Metaplasia

Intestinal metaplasia refers to the replacement of the differentiated and mature normal mucosal epithelium outside the intestinal tract by the intestinal epithelium. This paper briefly describes the etiology and clinical significance of intestinal metaplasia in Barrett’s esophagus. This article summarizes the impact of intestinal metaplasia on the diagnosis, monitoring, and treatment of Barrett’s esophagus according to different guidelines. We also briefly explore the basis for the endoscopic diagnosis of intestinal metaplasia in Barrett’s esophagus. The identification techniques of goblet cells in Barrett’s esophagus are also elucidated by some scholars. Additionally, we further elaborate on the current treatment methods related to Barrett’s esophagus.

Diagnostic utility of a novel magnifying endoscopic classification system for superficial Barrett's esophagus-related neoplasms: a nationwide multicenter study

BACKGROUND

Currently, no classification system using magnification endoscopy for the diagnosis of superficial Barrett's esophagus (BE)-related neoplasia has been widely accepted. This nationwide multicenter study aimed to validate the diagnostic accuracy and reproducibility of the magnification endoscopy classification system, including the diagnostic flowchart developed by the Japan Esophageal Society-Barrett's esophagus working group (JES-BE) for superficial Barrett's esophagus-related neoplasms.

METHODS

The JES-BE acquired high-definition magnification narrow-band imaging (HM-NBI) images of non-dysplastic and dysplastic BE from 10 domestic institutions. A total of 186 high-quality HM-NBI images were selected. Thirty images were used for the training phase and 156 for the validation (test) phase. We invited five non-experts and five expert reviewers. In the training phase, the reviewers discussed how to correctly predict the histology based on the JES-BE criteria. In the validation phase, they evaluated whether the criteria accurately predicted the histology results according to the diagnostic flowchart. The validation phase was performed immediately after the training phase and at 6 weeks thereafter.

RESULTS

The sensitivity and specificity for all reviewers were 87% and 97%, respectively. Overall accuracy, positive predictive value, and negative predictive value were 91%, 98%, and 83%, respectively. The overall strength of inter-observer and intra-observer agreements for dysplastic histology prediction was κ = 0.77 and κ = 0.83, respectively. No significant difference in diagnostic accuracy and reproducibility between experts and non-experts was found.

CONCLUSION

The JES-BE classification system, including the diagnostic flowchart for predicting dysplastic BE, is acceptable and reliable, regardless of the clinician's experience level.

A computer-assisted algorithm for narrow-band imaging-based tissue characterization in Barrett's esophagus

BACKGROUND AND AIMS

The endoscopic evaluation of narrow-band imaging (NBI) zoom imagery in Barrett's esophagus (BE) is associated with suboptimal diagnostic accuracy and poor interobserver agreement. Computer-aided diagnosis (CAD) systems may assist endoscopists in the characterization of Barrett's mucosa. Our aim was to demonstrate the feasibility of a deep-learning CAD system for tissue characterization of NBI zoom imagery in BE.

METHODS

The CAD system was first trained using 494,364 endoscopic images of general endoscopic imagery. Next, 690 neoplastic BE and 557 nondysplastic BE (NDBE) white-light endoscopy overview images were used for refinement training. Subsequently, a third dataset of 112 neoplastic and 71 NDBE NBI zoom images with histologic correlation was used for training and internal validation. Finally, the CAD system was further trained and validated with a fourth, histologically confirmed dataset of 59 neoplastic and 98 NDBE NBI zoom videos. Performance was evaluated using fourfold cross-validation. The primary outcome was the diagnostic performance of the CAD system for classification of neoplasia in NBI zoom videos.

RESULTS

The CAD system demonstrated accuracy, sensitivity, and specificity for detection of BE neoplasia using NBI zoom images of 84%, 88%, and 78%, respectively. In total, 30,021 individual video frames were analyzed by the CAD system. Accuracy, sensitivity, and specificity of the video-based CAD system were 83% (95% confidence interval [CI], 78%-89%), 85% (95% CI, 76%-94%), and 83% (95% CI, 76%-90%), respectively. The mean assessment speed was 38 frames per second.

CONCLUSION

We have demonstrated promising diagnostic accuracy of predicting the presence/absence of Barrett's neoplasia on histologically confirmed unaltered NBI zoom videos with fast corresponding assessment time.

Advanced endoscopic imaging for detecting and guiding therapy of early neoplasias of the esophagus

Esophageal cancers, largely adenocarcinoma in Western countries and squamous cell cancer in Asia, present a significant burden of disease and remain one of the most lethal of cancers. Key to improving survival is the development and adoption of new imaging modalities to identify early neoplastic lesions, which may be small, multifocal, subsurface, and difficult to detect by standard endoscopy. Such advanced imaging is particularly relevant with the emergence of ablative techniques that often require multiple endoscopic sessions and may be complicated by bleeding, pain, strictures, and recurrences. Assessing the specific location, depth of involvement, and features correlated with neoplastic progression or incomplete treatment may optimize treatments. While not comprehensive of all endoscopic imaging modalities, we review here some of the recent advances in endoscopic luminal imaging, particularly with surface contrast enhancement using virtual chromoendoscopy, highly magnified subsurface imaging with confocal endomicroscopy, optical coherence tomography, elastic scattering spectroscopy, angle-resolved low-coherence interferometry, and light scattering spectroscopy. While there is no single ideal imaging modality, various multimodal instruments are also being investigated. The future of combining computer-aided assessments, molecular markers, and improved imaging technologies to help localize and ablate early neoplastic lesions shed hope for improved disease outcome.

Feasibility of a simplified narrow-band imaging classification system for Barrett's esophagus for novice endoscopists

BACKGROUND

Narrow-band imaging (NBI) classifications for Barrett's esophagus have been proposed for the detection of early esophageal adenocarcinoma. We developed a simplified classification system with demonstrated high diagnostic accuracy and reproducibility among experienced endoscopists, but the feasibility of this system among novice endoscopists was unclear.

METHODS

In the present study, eight novice endoscopists with no experience of magnification endoscopy were asked to review 248 images of Barrett's esophagus (72 dysplastic, 176 non-dysplastic) obtained using high-definition magnification endoscopy with NBI 6 weeks before (1st test), immediately after (2nd test), and 6 weeks after (3rd test) being taught the simplified classification system. The primary outcomes were differences in diagnostic accuracy for dysplasia among the three tests.

RESULTS

The specificity and overall accuracy improved significantly in the 2nd vs. 1st test [97% vs. 80% (p < 0.001) and 94% vs. 82% (p < 0.001), respectively], but sensitivity was comparable (87% in both tests; p = 0.42). In the 3rd test, the sensitivity and overall accuracy decreased significantly compared with the 2nd test [82% vs. 87% (p < 0.001) and 93% vs. 94% (p < 0.05), respectively], but there was no significant difference in specificity (97% in both tests; p = 0.16). The kappa values for interobserver agreement for the mucosal pattern, vascular pattern, and predicted histology were substantial, and improved significantly in the 2nd vs. 1st test (0.78 vs. 0.59, 0.70 vs. 0.53, and 0.79 vs. 0.66, respectively; p < 0.001 for all).

CONCLUSIONS

The simplified NBI classification system may be appropriate for novice endoscopists to use in providing high accuracy and reproducibility.

A roadmap for the clinical implementation of optical-imaging biomarkers

Clinical workflows for the non-invasive detection and characterization of disease states could benefit from optical-imaging biomarkers. In this Perspective, we discuss opportunities and challenges towards the clinical implementation of optical-imaging biomarkers for the early detection of cancer by analysing two case studies: the assessment of skin lesions in primary care, and the surveillance of patients with Barrett's oesophagus in specialist care. We stress the importance of technical and biological validations and clinical-utility assessments, and the need to address implementation bottlenecks. In addition, we define a translational roadmap for the widespread clinical implementation of optical-imaging technologies.

Endoscopic diagnosis and treatment of esophageal adenocarcinoma: introduction of Japan Esophageal Society classification of Barrett's esophagus

Endoscopic surveillance of Barrett's esophagus has become a foundation of the management of esophageal adenocarcinoma (EAC). Surveillance for Barrett's esophagus commonly involves periodic upper endoscopy with biopsies of suspicious areas and random four-quadrant biopsies. However, targeted biopsies using narrow-band imaging can detect more dysplastic areas and thus reduce the number of biopsies required. Several specific mucosal and vascular patterns characteristic of Barrett's esophagus have been described, but the proposed criteria are complex and diverse. Simpler classifications have recently been developed focusing on the differentiation between dysplasia and non-dysplasia. These include the Japan Esophageal Society classification, which defines regular and irregular patterns in terms of mucosal and vascular shapes. Cancer invasion depth is diagnosed by endoscopic ultrasonography (EUS); however, a meta-analysis of EUS staging of superficial EAC showed favorable pooled values for mucosal cancer staging, but unsatisfactory diagnostic results for EAC at the esophagogastric junction. Endoscopic resection has recently been suggested as a more accurate staging modality for superficial gastrointestinal cancers than EUS. Following endoscopic resection for gastrointestinal cancers, the risk of metastasis can be evaluated based on the histology of the resected specimen. European guidelines describe endoscopic resection as curative for well- or moderately differentiated mucosal cancers without lymphovascular invasion, and these criteria might be extended to lesions invading the submucosa (≤ 500 μm), i.e., to low-risk, well- or moderately differentiated tumors without lymphovascular involvement, and < 3 cm. These criteria were confirmed by a recent study in Japan.

Machine Learning Creates a Simple Endoscopic Classification System that Improves Dysplasia Detection in Barrett's Oesophagus amongst Non-expert Endoscopists

INTRODUCTION

Barrett's oesophagus (BE) is a precursor to oesophageal adenocarcinoma (OAC). Endoscopic surveillance is performed to detect dysplasia arising in BE as it is likely to be amenable to curative treatment. At present, there are no guidelines on who should perform surveillance endoscopy in BE. Machine learning (ML) is a branch of artificial intelligence (AI) that generates simple rules, known as decision trees (DTs). We hypothesised that a DT generated from recognised expert endoscopists could be used to improve dysplasia detection in non-expert endoscopists. To our knowledge, ML has never been applied in this manner.

METHODS

Video recordings were collected from patients with non-dysplastic (ND-BE) and dysplastic Barrett's oesophagus (D-BE) undergoing high-definition endoscopy with i-Scan enhancement (PENTAX®). A strict protocol was used to record areas of interest after which a corresponding biopsy was taken to confirm the histological diagnosis. In a blinded manner, videos were shown to 3 experts who were asked to interpret them based on their mucosal and microvasculature patterns and presence of nodularity and ulceration as well as overall suspected diagnosis. Data generated were entered into the WEKA package to construct a DT for dysplasia prediction. Non-expert endoscopists (gastroenterology specialist registrars in training with variable experience and undergraduate medical students with no experience) were asked to score these same videos both before and after web-based training using the DT constructed from the expert opinion. Accuracy, sensitivity, and specificity values were calculated before and after training where p < 0.05 was statistically significant.

RESULTS

Videos from 40 patients were collected including 12 both before and after acetic acid (ACA) application. Experts' average accuracy for dysplasia prediction was 88%. When experts' answers were entered into a DT, the resultant decision model had a 92% accuracy with a mean sensitivity and specificity of 97% and 88%, respectively. Addition of ACA did not improve dysplasia detection. Untrained medical students tended to have a high sensitivity but poor specificity as they "overcalled" normal areas. Gastroenterology trainees did the opposite with overall low sensitivity but high specificity. Detection improved significantly and accuracy rose in both groups after formal web-based training although it did it reach the accuracy generated by experts. For trainees, sensitivity rose significantly from 71% to 83% with minimal loss of specificity. Specificity rose sharply in students from 31% to 49% with no loss of sensitivity.

CONCLUSION

ML is able to define rules learnt from expert opinion. These generate a simple algorithm to accurately predict dysplasia. Once taught to non-experts, the algorithm significantly improves their rate of dysplasia detection. This opens the door to standardised training and assessment of competence for those who perform endoscopy in BE. It may shorten the learning curve and might also be used to compare competence of trainees with recognised experts as part of their accreditation process.

Intra and interobserver agreement of narrow band imaging for the detection of head and neck tumors

BACKGROUND

Narrow band imaging (NBI) in combination with white light endoscopy (WLE) has improved the accuracy for the diagnosis and follow-up of head and neck carcinomas by identifying changes in the vascular patterns of the mucosa. However, NBI evaluation is explorer-dependent and may be influenced by the learning curve. The aim of this study is to assess the intra and interobserver agreement of NBI and WLE at the office, under local anaesthesia, by either experienced or non-experienced observers.

METHODS

Eighty-seven images of head and neck lesions were routinely collected under WLE and NBI. A group of three experienced otolaryngologists and three medical students assessed the images after a brief training. No additional patient information was provided. The same protocol was repeated after three weeks. Intra and interobserver agreement were calculated with the kappa index.

RESULTS

NBI intraobserver agreement was substantial (κ = 0.62) and better than with WLE alone, which was moderate (κ = 0.57) in both groups. Interobserver agreement was moderate with WLE (κ = 0.58) and substantial with NBI (κ = 0.63). Both groups improved intraobserver and interobserver agreement with the implementation of NBI.

CONCLUSIONS

Intra and interobserver agreement with NBI for the evaluation of head and neck lesions are substantial, and improve the results of WLE alone in both, professionals and trainees.

Impact of advanced endoscopic imaging on Barrett's esophagus in daily clinical practice

BACKGROUND AND AIMS

Several advanced imaging techniques have been proposed to improve the visualization of dysplastic regions within Barrett's epithelium, with some evidence for the use of narrow-band imaging (NBI) and acetic acid chromoendoscopy (AAC).

METHODS

We retrospectively analyzed consecutive cases of Barrett's esophagus, diagnosed using white-light endoscopy and confirmed histologically by the presence of intestinal metaplasia, between April 2007 and April 2010 in a large community hospital. A change in practice was then instituted, whereby a Barrett's team consisting of specialist endoscopists was formed in an attempt to standardize and improve the quality of surveillance. Barrett's epithelium was inspected with both white-light imaging and NBI in all patients. Where the length of Barrett's epithelium was 3 cm or more, AAC was also used. One and a half percent acetic acid was sprayed onto the Barrett's segment and loss of aceto-whitening observed after a 2-minute period. Any abnormal areas noted during advanced imaging underwent target biopsy sampling. We subsequently compared the dysplasia detection rate in Barrett's epithelium identified between April 2011 and April 2014 after these changes. Observed differences between the cohorts were analyzed with the Fisher exact test and the Student t test.

RESULTS

From 2007 to 2010 Barrett's esophagus was identified during 560 gastroscopies in 392 individual patients. The mean maximal Barrett's esophagus recorded length was 4.4 cm (range, 1-10), with an average of 4.7 esophageal biopsy specimens taken per endoscopy. In comparison, from 2011 to 2014 Barrett's esophagus was identified during 856 endoscopies in 630 patients. From 2011 to 2014 the Barrett's team performed 85% of all procedures using the aforementioned techniques. The mean maximal Barrett's esophagus length was 3.8 cm (range, 1-16), with an increased average of 5.8 biopsy specimens per endoscopy taken (P < .01). Both cohorts were comparable in age and gender distribution. Our data demonstrated no significant difference in the relative frequencies of occurrence of dysplasia detected between both cohorts of patients. From 2007 to 2010 dysplasia was detected in 11.0% (n = 43) of patients. This consisted of low-grade dysplasia in 7.7% of patients and high-grade dysplasia or cancer 3.3%. From 2011 to 2014 this compared with dysplasia in 11.3% (n = 71) of patients, with low-grade dysplasia in 9.4% and high-grade dysplasia or cancer in 1.9%.

CONCLUSIONS

Our data show that the use of NBI and AAC in the imaging of Barrett's esophagus did not result in an increased detection rate of dysplasia in routine clinical practice. These findings concur with the recommendations of existing Barrett's esophagus surveillance guidelines, which advocate the continued use of quadratic biopsy sampling within general surveillance programs.

Image assessment of Barrett's esophagus using the simplified narrow band imaging classification

BACKGROUND

A simplified narrow band imaging (NBI) classification has been proposed with the objective of integrating multiple classifications of NBI surface patterns in Barrett's esophagus (BE). Little is known about the impact of the simplified NBI classification on the diagnosis of BE when using high-definition magnification endoscopy with NBI (HM-NBI). This study aimed to evaluate (a) the reproducibility of NBI surface patterns and predicted histology and (b) the diagnostic accuracy of interpreting HM-NBI images by using the simplified NBI classification.

METHODS

Two hundred and forty-eight HM-NBI images from macroscopically normal areas in patients with BE were retrieved from endoscopy databases and randomized for review by four endoscopists (two experts, two non-experts). We evaluated inter- and intra-observer agreement of the interpretation of NBI surface patterns and the predicted histology (dysplasia vs. non-dysplasia), as calculated by using κ statistics, and diagnostic values of the prediction.

RESULTS

The overall inter-observer agreements were substantial for mucosal pattern (κ = 0.73) and vascular pattern (κ = 0.71), and almost perfect for predicting dysplastic histology (κ = 0.80). The overall intra-observer agreements were almost perfect for mucosal (κ = 0.84) and vascular patterns (κ = 0.86), and predicting dysplastic histology (κ = 0.89). The mean accuracy in predicting dysplastic histology for all reviewers was 95 % (experts: 96.8 %, non-experts: 93.1 %).

CONCLUSIONS

The simplified NBI classification has the potential to provide high diagnostic reproducibility and accuracy when using HM-NBI.

Narrow band imaging improves observer reliability in evaluation of upper aerodigestive tract lesions

OBJECTIVES/HYPOTHESIS

Visualization by endoscopy is essential in the diagnosis of upper aerodigestive tract lesions. Recent studies showed that narrow band imaging (NBI) increases the diagnostic potential of conventional white light imaging (WLI) by highlighting the superficial vessels. The objective of this study was to evaluate whether the use of NBI would influence inter- and intraobserver agreement while making diagnostic decisions using rigid endoscopy of the upper aerodigestive tract.

STUDY DESIGN

Retrospective study.

METHODS

One hundred routinely collected pictures of laryngeal, hypopharyngeal, and oropharyngeal lesions were used. Rigid endoscopies and patient data collection were performed according to standard protocol. Twelve observers, grouped in different levels of experience, assessed all lesions twice with a 2 to 4 week interval. Fleiss and Cohen's kappa (κ) values were calculated to assess inter- and intraobserver agreement.

RESULTS

Overall interobserver agreement increased from κ = 0.34 to κ = 0.40 by adding NBI to WLI (WLI and WLI + NBI, respectively). In experienced observers, an improvement from κ = 0.39 to κ = 0.43 was observed; in less-experienced observers an improvement from κ = 0.30 to κ = 0.37 was observed. Overall intraobserver agreement increased from moderate (κ = 0.54) to substantial (κ = 0.63) with addition of NBI. Intraobserver agreement for less-experienced observers improved remarkably when WLI was combined with NBI (κ = 0.51 vs. κ = 0.67).

CONCLUSIONS

Addition of NBI during rigid endoscopies of the upper aerodigestive tract led to improvement of both inter- and intraobserver agreement.

LEVEL OF EVIDENCE

4 Laryngoscope, 126:2276-2281, 2016.

Endoscopic imaging of Barrett’s esophagus

The incidence of esophageal adenocarcinoma (EAC) has dramatically increased in the United States as well as Western European countries. The majority of esophageal adenocarcinomas arise from a backdrop of Barrett’s esophagus (BE), a premalignant lesion that can lead to dysplasia and cancer. Because of the increased risk of EAC, GI society guidelines recommend endoscopic surveillance of patients with BE. The emphasis on early detection of dysplasia in BE through surveillance endoscopy has led to the development of advanced endoscopic imaging technologies. These techniques have the potential to both improve mucosal visualization and characterization and to detect small mucosal abnormalities which are difficult to identify with standard endoscopy. This review summarizes the advanced imaging technologies used in evaluation of BE.

Development and Validation of a Classification System to Identify High-Grade Dysplasia and Esophageal Adenocarcinoma in Barrett's Esophagus Using Narrow-Band Imaging

BACKGROUND & AIMS

Although several classification systems have been proposed for characterization of Barrett's esophagus (BE) surface patterns based on narrow-band imaging (NBI), none have been widely accepted. The Barrett's International NBI Group (BING) aimed to develop and validate an NBI classification system for identification of dysplasia and cancer in patients with BE.

METHODS

The BING working group, composed of NBI experts from the United States, Europe, and Japan, met to develop a validated, consensus-driven NBI classification system for identifying dysplasia and cancer in BE. The group reviewed 60 NBI images of nondysplastic BE, high-grade dysplasia, and esophageal adenocarcinoma to characterize mucosal and vascular patterns visible by NBI; these features were used to develop the BING criteria. We then recruited adult patients undergoing surveillance or endoscopic treatment for BE at 4 institutions in the United States and Europe, obtaining high-quality NBI images and performing histologic analysis of biopsies. Experts individually reviewed 50 NBI images to validate the BING criteria, and then evaluated 120 additional NBI images (not previously viewed) to determine whether the criteria accurately predicted the histology results.

RESULTS

The BING criteria identified patients with dysplasia with 85% overall accuracy, 80% sensitivity, 88% specificity, 81% positive predictive value, and 88% negative predictive value. When dysplasia was identified with a high level of confidence, these values were 92%, 91%, 93%, 89%, and 95%, respectively. The overall strength of inter-observer agreement was substantial (κ = 0.681).

CONCLUSIONS

The BING working group developed a simple, internally validated system to identify dysplasia and EAC in patients with BE based on NBI results. When images are assessed with a high degree of confidence, the system can classify BE with >90% accuracy and a high level of inter-observer agreement.

Red flag imaging in Barrett's esophagus: does it help to find the needle in the haystack?

Esophageal Adenocarcinoma (EAC) has suffered a sharp increase on its incidence for the last decades, and it is associated with a poor prognosis. Barrett's Esophagus (BE) is the most important identifiable risk factor for the progression to esophageal adenocarcinoma. The key to prevent and provide a curative treatment of esophageal adenocarcinoma is the detection and eradication of early neoplasia in patients with esophagus. Endoscopic surveillance is evolving from a blind or random four quadrant biopsies protocol (Seattle protocol) to a more targeted approach. A detailed white light examination with high-resolution endoscopy is the cornerstone for recognition of early neoplastic lesions in BE. Additional imaging modalities may enhance targeting of lesions or provide more information at a focused level. There are emerging data that some of these new modalities can increase the yield of detecting dysplasia, although its routine use has yet to be validated.

Recent development of optical coherence tomography for preoperative diagnosis of esophageal malignancies

Endoscopic diagnosis with histological evidence is necessary to decide the best strategy for treating esophageal squamous cell carcinoma and Barrett's-associated neoplasia, and the recent development of endoscopic technologies have made possible real-time information of malignant hallmarks. We focused on the development of optical coherence tomography (OCT), the only technology that can depict real-time cross-sectional images with high resolution. With the improvements in image resolution, acquisition rate and demonstrable area of three-dimensional devices with Doppler capability, OCT imaging was shown to enable visualization of structural/functional alterations in the mucosal/submucosal tissue of the esophagus, resulting in more accurate preoperative diagnosis of such malignancies. Moreover, it approved to be useful for targeting malignant areas for biopsy and treatment as well as for predicting the treatment effects. Therefore, further development of this technology is expected to overcome the current clinical issues in management strategies of esophageal malignancies.

The changing role of the pathologist in the management of Barrett's oesophagus

Pathological specimens from columnar-lined oesophagus (CLO) comprise a considerable proportion of the workload of gastrointestinal pathologists in Western countries. There remain controversies concerning the diagnostic role of pathology. More recently, in the UK at least, the diagnosis has been regarded as primarily an endoscopic endeavour, with pathology being corroborative and only diagnostic when endoscopic features are equivocal or when there are additional features that make the endoscopic diagnosis unclear. There is also recognition that demonstration of intestinalisation or 'goblet cells' is not paramount, and should not be required for the diagnosis. There have been notable changes in the management of CLO neoplasia: pathologists are centrally involved in its management. Pathological assessment of endoscopic mucosal resection (EMR) specimens provides the most useful means of determining the management of early neoplasia and of determining indications for surgery. This represents an extraordinarily rapid change in management, in that, <10 years ago, laborious Seattle-type biopsy protocols were recommended, and high grade dysplasia was an indication for resectional surgery. Now, individual patient management is paramount: multi-professional meetings determine management after biopsy and EMR assessment. One significant change is that major resections are undertaken less often, in Western countries, for CLO neoplasia.

Electronic chromoendoscopy

Electronic chromoendoscopy technologies provide image enhancement and may improve the diagnosis of mucosal lesions. Although strides have been made in standardization of image characterization, especially with NBI, further image-to-pathology correlation and validation are required. There is promise for the development of a resect and discard policy for diminutive adenomas by using electronic chromoendoscopy; however, before this can be adopted, further community-based studies are needed. Further validated training tools for NBI, FICE, and i-SCAN will also be required for the use of these techniques to become widespread.

Simplified classification of capillary pattern in Barrett esophagus using magnifying endoscopy with narrow band imaging: implications for malignant potential and interobserver agreement

The classification of Barrett esophagus (BE) using magnifying endoscopy with narrow band imaging (ME-NBI) is not widely used in clinical settings because of its complexity. To establish a new simplified available classification using ME-NBI.We conducted a cross-sectional study in a single-referral center. One hundred eight consecutive patients with BE using ME-NBI and crystal violet (CV) chromoendoscopy, and histological findings were enrolled. BE areas observed by ME-NBI were classified as type I or II on the basis of capillary pattern (CP), and as closed or open type on the basis of a mucosal pit pattern using CV chromoendoscopy; then, biopsy samples were obtained. We evaluated the relation between CP and pit pattern, expression of the factors with malignant potential, percentage of microvascular density, and interobserver agreement.One hundred thirty lesions from 91 patients were analyzed. Type II CP had more open type pit pattern areas and significantly greater microvascular density than type I. The presence of dysplasia, specialized intestinal metaplasia, expressions of COX-2, CDX2, and CD34, and PCNA index were significantly higher in type II, whereas the multivariate analysis showed that type II was the best predictor for the presence of dysplasia (OR 11.14), CD34 expression (OR 3.60), and PCNA (OR 3.29). Interobserver agreement for this classification was substantial (κ = 0.66).A simplified CP classification based on observation with ME-NBI is presented. Our results indicate that the classification may be useful for surveillance of BE with high malignant potential.

Endoscopic assessment and management of early esophageal adenocarcinoma

Esophageal carcinoma affects more than 450000 people worldwide and the incidence is rapidly increasing. In the United States and Europe, esophageal adenocarcinoma has superseded esophageal squamous cell carcinoma in its incidence. Esophageal cancer has a high mortality rates secondary to the late presentation of most patients at advanced stages. Endoscopic screening is recommended for patients with multiple risk factors for cancer in Barrett’s esophagus. These risk factors include chronic gastroesophageal reflux disease, hiatal hernia, advanced age, male sex, white race, cigarette smoking, and obesity. The annual risk of esophageal cancer is approximately 0.25% for patients without dysplasia and 6% for patients with high-grade dysplasia. Twenty percent of all esophageal adenocarcinoma in the United States is early stage with disease confined to the mucosa or submucosa. The significant morbidity and mortality of esophagectomy make endoscopic treatment an attractive option. The American Gastroenterological Association recommends endoscopic eradication therapy for patients with high-grade dysplasia. Endoscopic modalities for treatment of early esophageal adenocarcinoma include endoscopic resection techniques and endoscopic ablative techniques such as radiofrequency ablation, photodynamic therapy and cryoablation. Endoscopic therapy should be precluded to patients with no evidence of lymphovascular invasion. Local tumor recurrence is low after endoscopic therapy and is predicted by poor differentiation of tumor, positive lymph node and submucosal invasion. Surgical resection should be offered to patients with deep submucosal invasion.

Endoscopic diagnosis of early Barrett's neoplasia: perspectives for advanced endoscopic technology

Barrett's esophagus (BE) is a metaplastic condition that occurs secondary to gastroesophageal reflux disease. BE is also a precursor to esophageal adenocarcinoma, which, although still rare in Japan, is one of the most rapidly increasing cancers in Western countries. However, the prevalence of gastroesophageal reflux disease has increased significantly over the past few decades in Japan, possibly leading to an incremental rise in BE and the associated inherent risk of adenocarcinoma. Given the poor prognosis of advanced-stage Barrett's adenocarcinoma, endoscopic surveillance is recommended for subjects with BE to detect early neoplasias including dysplasia. However, endoscopic identification of dysplastic lesions is still not sufficiently reliable or subjective, making targeted therapy extremely difficult. Over the past few years, improvements in image resolution, image processing software, and optical filter technology have enabled identification of dysplasia and early cancer in BE patients. We retrieved as many studies on advanced endoscopic technologies in BE as possible from MEDLINE and PubMed. The present review focuses on the emergent clinically available technologies to provide an overview of the technologies, their practical applicability, current status, and future challenges.

Red flag imaging techniques in Barrett's esophagus

The key to detection and treatment of early neoplasia in Barrett's esophagus (BE) is thorough and careful inspection of the Barrett's segment. The greatest role for red flag techniques is to help identify neoplastic lesions for targeted biopsy and therapy. High-definition white light endoscopy (HD-WLE) can potentially improve endoscopic imaging of BE compared with standard endoscopy, but little scientific evidence supports this. The addition of autofluorescence imaging to HD-WLE and narrow band imaging increases sensitivity and the false-positive rate without significantly improving overall detection of BE-related neoplasia.

Confocal laser endomicroscopy for in vivo diagnosis of Barrett's oesophagus and associated neoplasia: a pilot study conducted in a single Italian centre

BACKGROUND

Diagnosis and management of Barrett's oesophagus are controversial. Technical improvements in real-time recognition of intestinal metaplasia and neoplastic foci provide the chance for more effective target biopsies. Confocal laser endomicroscopy allows to analyze living cells during endoscopy.

AIMS

To assess the diagnostic accuracy, inter- and intra-observer variability of endomicroscopy for detecting in vivo neoplasia (dysplasia and/or early neoplasia) in Barrett's oesophagus.

METHODS

Prospective pilot study. Patients referred for known Barrett's oesophagus were screened. Endomicroscopy was carried out in a circular fashion, every 1-2 cm, on the whole columnar-lined distal oesophagus. Visible lesions, when present, were analyzed first. Targeted biopsies were taken. Confocal images were classified according to confocal Barrett classification. Endomicroscopic and histological findings were compared.

RESULTS

Forty-eight out of 50 screened patients underwent endomicroscopy. Visible lesions were observed in 3 patients. In a per-biopsy analysis, Barrett's-oesophagus-associated neoplasia could be predicted with an accuracy of 98.1%. The agreement between endomicroscopic and histological results was substantial (κ=0.76).

CONCLUSIONS

This study suggests that endomicroscopy can provide in vivo diagnosis of Barrett's oesophagus-associated neoplasia. Because it allows for the study of larger surface areas of the mucosa, endomicroscopy may lead to significant improvements in the in vivo screening and surveillance of Barrett's oesophagus.

Clinical utility and interobserver agreement of autofluorescence imaging and magnification narrow-band imaging for the evaluation of Barrett's esophagus: a prospective tandem study

BACKGROUND

New endoscopic imaging techniques, such as autofluorescence imaging (AFI) and narrow-band imaging (NBI), have been developed to improve the detection of neoplastic lesions in Barrett's esophagus (BE).

OBJECTIVE

To evaluate the clinical utility of AFI and magnification NBI to detect high-grade dysplasia (HGD) and early esophageal adenocarcinoma (EAC) and the interobserver agreement.

DESIGN

Prospective tandem study of eligible patients.

SETTING

Single, academic tertiary care center.

PATIENTS

Forty-two patients with a history of confirmed BE were prospectively enrolled.

INTERVENTIONS

The BE segment was examined under high-definition white-light endoscopy, and the presence of visible lesions was recorded. Subsequently, AFI and magnification NBI were performed in tandem on areas of the BE segment away from visible lesions; images obtained by these 2 systems were graded according to the color of reflected light and surface patterns, respectively. Biopsy specimens were obtained at the end of the procedure.

MAIN OUTCOME MEASUREMENTS

The sensitivity, specificity, positive predictive value, and negative predictive value (NPV) of the AFI and NBI patterns for the detection of HGD/EAC and interobserver agreement.

RESULTS

Of the 42 patients enrolled, 14 (33%) had HGD/EAC. On patient-based analysis, AFI alone had a sensitivity, specificity, and NPV of 50%, 61%, and 71%, respectively, and the overall accuracy for the detection of HGD/EAC patients was 57%. By using magnification NBI in tandem fashion, the sensitivity and NPV improved to 71% and 76%, respectively, with a decrease in specificity to 46% and in overall accuracy to 55%. The 2 techniques had moderate interobserver agreement for both the patterns and prediction of histology.

LIMITATIONS

Uncontrolled study performed at an academic center by expert endoscopists in a high-risk population.

CONCLUSIONS

By using a multimodality endoscope, both AFI and magnification NBI had limited clinical accuracy and moderate overall interobserver agreement. AFI does not appear to be useful as a broad-based technique for the detection of neoplasia in patients with BE.

Endoscopic resection (endoscopic submucosal dissection/endoscopic mucosal resection) for superficial Barrett's esophageal cancer

Recently developed endoscopic resection (endoscopic submucosal dissection [ESD]/ endoscopic mucosal resection) has dramatically changed the therapeutic approach for Barrett's esophageal cancer. The rationale for endoscopic resection is that lesions confined to the mucosal layer have negligible risk for developing lymph node metastasis and can be successfully eradicated by endoscopic treatment as a curative treatment with minimal invasiveness. According to some reports that analyzed the rate of lymph-node involvement relative to the depth of mucosal or submucosal tumor infiltration, endoscopic resection is clearly indicated for intramucosal carcinoma and might be extended to lesions with invasion into the submucosa (<200 μm, sm1) because of the low risk for lymph node metastasis. Most Japanese experts recommend ESD for Barrett's esophageal cancer after accurate diagnosis of the margin of cancer using narrow band imaging with magnifying endoscopy because of its high curative rate. However, few studies have evaluated the long-term outcomes of endoscopic resection for Barrett's esophageal cancer in Japan. Further investigations should be conducted to establish endoscopic resection for Barrett's esophageal cancer.

Endoscopic assessment and grading of Barrett's esophagus using magnification endoscopy and narrow band imaging: impact of structured learning and experience on the accuracy of the Amsterdam classification system

OBJECTIVE

Several classification systems have been launched to characterize Barrett's esophagus (BE) mucosa using magnification endoscopy with narrow band imaging (ME-NBI). The good accuracy and interobserver agreement described in the early reports were not reproduced subsequently. Recently, we reported somewhat higher accuracy of the classification developed by the Amsterdam group. The critical question then formulated was whether a structured learning program and the level of experience would affect the clinical usefulness of this classification.

MATERIAL & METHODS

Two hundred and nine videos were prospectively captured from patients with BE using ME-NBI. From these, 70 were randomly selected and evaluated by six endoscopists with different levels of expertise, using a dedicated software application. First, an educational set was studied. Thereafter, the 70 test videos were evaluated. After classification of each video, the respective histological feedback was automatically given.

RESULTS

Within the learning process, there was a decrease in the time needed for evaluation and an increase in the certainty of prediction. The accuracy did not increase with the learning process. The sensitivity for detection of intestinal metaplasia ranged between 39% and 57%, and for neoplasia between 62% and 90%, irrespective of assessor's expertise. The kappa coefficient for the interobserver agreement ranged from 0.25 to 0.30 for intestinal metaplasia, and from 0.39 to 0.48 for neoplasia.

CONCLUSION

Using a dedicated learning program, the ME-NBI Amsterdam classification system is suboptimal in terms of accuracy and inter- and intraobserver agreements. These results reiterate the questionable utility of corresponding classification system in clinical routine practice.

Diagnosis and management of Barrett’s metaplasia: What’s new

Barrett’s esophagus (BE) is a complication of gastroesophageal reflux disease, and a premalignant lesion for esophageal adenocarcinoma (EAC). Observational studies suggest that endoscopic surveillance is associated with the detection of dysplasia and EAC at an early stage along with improved survival, but controversies still remain. The management of patients with BE involves endoscopic surveillance, preventive and clinical measures for cancer, and endoscopic and surgical approaches to treatment. Deciding upon the most appropriate treatment is a challenge. This study presents the results and the effectiveness of these practices.

Advanced endoscopic imaging for Barrett's Esophagus: current options and future directions

Barrett's esophagus is the precursor to esophageal adenocarcinoma, one of the most rapidly increasing cancers in the United States. Given the poor prognosis of late-stage adenocarcinoma, endoscopic surveillance is recommended for subjects with Barrett's esophagus to detect early neoplasia. Current guidelines recommend "random" four-quadrant biopsies taken every 1-2 cm throughout the Barrett's segment. However, this only samples a minority of epithelium and has been shown to miss areas of endoscopically- inapparent neoplasia (high grade dysplasia or cancer). Recent efforts have focused on developing novel diagnostic imaging technologies to detect the subtle epithelial changes associated with dysplasia and neoplasia in Barrett's esophagus. Some of these modalities serve as "red flag" technologies designed to detect areas of abnormality within large surface areas. Other technologies serve to characterize areas of visible abnormality, offering a higher spatial resolution to confirm/exclude the presence of neoplasia. This review summarizes several available and evolving imaging technologies used in the endoscopic diagnosis and surveillance of Barrett's associated neoplasia.

Endoscopic therapies for Barrett's-associated dysplasia: a new paradigm for a new decade

The emergence of endoscopic therapies for Barrett's esophagus (BE)-associated dysplasia has significantly altered the management of this complex disease. Over the past decade, there has been a paradigm shift from that of pure surveillance to a more therapeutic approach in eradicating dysplastic BE. This strategy includes less invasive options than esophagectomy for high-grade dysplasia and early eradication of confirmed low-grade dysplasia. Although multiple modalities exist for endoscopic therapy, endoscopic mucosal resection coupled with radiofrequency ablation appears to be the most effective therapy, with minimal complications. Recent advances in endoscopic eradication therapies for dysplastic BE have fueled excitement for a significant weapon against the rising incidence of esophageal cancer.

Endotherapy for Barrett's esophagus

Endotherapy is now the mainstay of therapy for Barrett's associated neoplasia. The approach should begin with confirmation of neoplasia by a gastrointestinal pathologist, patient counseling, and appropriate endoscopic work up. Detailed examination with high-resolution white light endoscopy is the most important tool for detection of neoplasia. Further validation studies are needed for many enhanced imaging modalities before being recommended as part of the standard work up and assessment of patients with Barrett's esophagus (BE). Endoscopic mucosal resection is required for any visible lesion in the setting of dysplasia for accurate histological diagnosis. The remainder of the epithelium may be treated with resection or ablative therapy, followed by adequate surveillance. Patients with nondysplastic Barrett's require further risk stratification before incorporation of ablative therapy for this population. The future will fortify the endoscopic role in Barrett's with validation trials for endoscopic assessment, further long-term results for each of the treatment modalities, potential risk stratification for patients with BE, and improved guidelines for surveillance after therapy.

[Endoscopic technique in endobrachyoesophagus diagnosis: Chromoendoscopy and acetic acid]

Screening for complications of neoplastic Barrett's oesophagus requires a tedious blind standardized protocol biopsies quadrant every 1 to 2cm depending on the morphology of the Barrett's epithelium (Protocol of Seattle). To achieve that biopsies targeted to areas suspicious of dysplasia, a method of high sensitivity is required. Chromoendoscopy has been developed in this direction. Acetic acid combined with high resolution endoscopy and zooming represents an aid in the preparation of the oesophageal mucosa for visualization of suspicious anomalies. It is safe, cheap and easy to use. Acetic acid has proven its value in improving the visibility of the pit pattern. Several vital dyes have been tested, including methylene blue, indigo carmine and crystal violet, with mixed results. The FICE(®) and NBI(®), immediate, reversible and attractive virtual chromoendoscopy techniques represent interesting tools for improving sensitivity in screening for Barrett's oesophagus and its complications. Confocal endomicroscopy, which is similar as a "per-endoscopic real time histological examination", seems to be equally a promising technique in detection of Barrett's oesophagus associated neoplasia. But these tools which are capable of improvement so far, have not proved their use on a large population. For this, the systematic biopsy protocol Seattle remains the "gold standard" in monitoring the Barrett's oesophagus.

Narrow band imaging to detect residual or recurrent neoplastic tissue during surveillance endoscopy

BACKGROUND

There is little data on the prevalence of residual neoplastic tissue or the rate of endoscopically detected recurrence in patients with prior surgical or endoscopic resection of advanced neoplasia.

AIMS

To compare standard white light with NBI for both the detection, as well as the differentiation, of residual or recurrent neoplastic tissue during real-time endoscopy.

METHODS

A prospective study of 46 consecutive patients undergoing surveillance colonoscopy or upper endoscopy was conducted. Prior resection sites were examined first with white light and then with NBI. Main outcome measurements included the number of distinct lesions identified with white light, the number of additional lesions identified with NBI, and the overall accuracy of endoscopic diagnosis using white light alone or with NBI.

RESULTS

Sixty discrete lesions were identified, 43 with white light alone, and an additional 17 with NBI. NBI identified more lesions per patient than white light alone (mean 1.33 vs. 0.96, p < 0.05) and there was a trend towards increased detection of neoplastic lesions. Recurrent/residual neoplasia was present in 14 patients (30%) and there was a trend towards increased detection with the addition of NBI. About 63% of lesions identified with white light appeared more extensive when examined with NBI. The diagnostic accuracy in predicting histology was equivalent for NBI and white light (87 vs. 88%), though there was a trend towards higher sensitivity for neoplastic lesions with NBI (88 vs. 69%, p = 0.16).

CONCLUSIONS

A substantial number of patients undergoing surveillance endoscopy had residual or recurrent neoplastic tissue identified at the prior resection site. As NBI detected additional neoplastic lesions as well as demonstrated that lesions detected with white light were more extensive, adjunctive use of NBI for examining post-endoscopy resection sites should be studied in future, larger studies.

Endoscopic trimodal imaging versus standard video endoscopy for detection of early Barrett's neoplasia: a multicenter, randomized, crossover study in general practice

BACKGROUND

Endoscopic trimodal imaging (ETMI) may improve detection of early neoplasia in Barrett's esophagus (BE). Studies with ETMI so far have been performed in tertiary referral settings only.

OBJECTIVE

To compare ETMI with standard video endoscopy (SVE) for the detection of neoplasia in BE patients with an intermediate-risk profile.

DESIGN

Multicenter, randomized, crossover study.

SETTING

Community practice.

PATIENTS AND METHODS

BE patients with confirmed low-grade intraepithelial neoplasia (LGIN) underwent both ETMI and SVE in random order (interval 6-16 weeks). During ETMI, BE was inspected with high-resolution endoscopy followed by autofluorescence imaging (AFI). All visible lesions were then inspected with narrow-band imaging. During ETMI and SVE, visible lesions were sampled followed by 4-quadrant random biopsies every 2 cm.

MAIN OUTCOME MEASUREMENTS

Overall histological yield of ETMI and SVE and targeted histological yield of ETMI and SVE.

RESULTS

A total of 99 patients (79 men, 63±10 years) underwent both procedures. ETMI had a significantly higher targeted histological yield because of additional detection of 22 lesions with LGIN/high-grade intraepithelial neoplasia (HGIN)/carcinoma (Ca) by AFI. There was no significant difference in the overall histological yield (targeted+random) between ETMI and SVE. HGIN/Ca was diagnosed only by random biopsies in 6 of 24 patients and 7 of 24 patients, with ETMI and SVE, respectively.

LIMITATIONS

Inspection, with high-resolution endoscopy and AFI, was performed sequentially.

CONCLUSION

ETMI performed in a community-based setting did not improve the overall detection of dysplasia compared with SVE. The diagnosis of dysplasia is still being made in a significant number of patients by random biopsies. Patients with a confirmed diagnosis of LGIN have a significant risk of HGIN/Ca. (

CLINICAL TRIAL REGISTRATION NUMBER

ISRCTN91816824; NTR867.).

Autofluorescence imaging and magnification endoscopy

It is well known that angiogenesis is critical in the transition from premalignant to malignant lesions. Consequently, early detection and diagnosis based on morphological changes to the microvessels are crucial. In the last few years, new imaging techniques which utilize the properties of light-tissue interaction have been developed to increase early diagnosis of gastrointestinal (GI) tract neoplasia. We analyzed several “red-flag” endoscopic techniques used to enhance visualization of the vascular pattern of preneoplastic and neoplastic lesions (e.g. trimodal imaging including autofluorescence imaging, magnifying endoscopy and narrow band imaging). These new endoscopic techniques provide better visualization of mucosal microsurface structure and microvascular architecture and may enhance the diagnosis and characterization of mucosal lesions in the GI tract. In the near future, it is expected that trimodal imaging endoscopy will be practiced as a standard endoscopy technique as it is quick, safe and accurate for making a precise diagnosis of gastrointestinal pathology, with an emphasis on the diagnosis of early GI tract cancers. Further large-scale randomized controlled trials comparing these modalities in different patient subpopulations are warranted before their endorsement in the routine practice of GI endoscopy.

Endoscopic assessment and grading of Barrett's esophagus using magnification endoscopy and narrow-band imaging: accuracy and interobserver agreement of different classification systems (with videos)

BACKGROUND

Three different classification systems for the evaluation of Barrett's esophagus (BE) using magnification endoscopy (ME) and narrow-band imaging (NBI) have been proposed. Until now, no comparative and external evaluation of these systems in a clinical-like situation has been performed.

OBJECTIVE

To compare and validate these 3 classification systems.

DESIGN

Prospective validation study.

SETTING

Tertiary-care referral center. Nine endoscopists with different levels of expertise from Europe and Japan participated as assessors.

PATIENTS

Thirty-two patients with long-segment BE.

INTERVENTIONS

From a group of 209 standardized prospective recordings collected on BE by using ME combined with NBI, 84 high-quality videos were randomly selected for evaluation. Histologically, 28 were classified as gastric type mucosa, 29 as specialized intestinal metaplasia (SIM), and 27 as SIM with dysplasia/cancer. Assessors were blinded to underlying histology and scored each video according to the respective classification system. Before evaluation, an educational set concerning each classification system was carefully studied. At each assessment, the same 84 videos were displayed, but in different and random order.

MAIN OUTCOME MEASUREMENTS

Accuracy for detection of nondysplastic and dysplastic SIM. Interobserver agreement related to each classification.

RESULTS

The median time for video evaluation was 25 seconds (interquartile range 20-39 seconds) and was longer with the Amsterdam classification (P < .001). In 65% to 69% of the videos, assessors described certainty about the histology prediction. The global accuracy was 46% and 47% using the Nottingham and Kansas classifications, respectively, and 51% with the Amsterdam classification. The accuracy for nondysplastic SIM identification ranged between 57% (Kansas and Nottingham) and 63% (Amsterdam). Accuracy for dysplastic tissue was 75%, irrespective of the classification system and assessor expertise level. Interobserver agreement ranged from fair (Nottingham, κ = 0.34) to moderate (Amsterdam and Kansas, κ = 0.47 and 0.44, respectively).

LIMITATION

No per-patient analysis.

CONCLUSIONS

All of the available classification systems could be used in a clinical-like environment, but with inadequate interobserver agreement. All classification systems based on combined ME and NBI, revealed substantial limitations in predicting nondysplastic and dysplastic BE when assessed externally. This technique cannot, as yet, replace random biopsies for histopathological analysis.

Endoscopy in gastro-oesophageal reflux disease

Although gastro-oesophageal reflux disease is basically a clinical diagnosis, oesophago-gastroduodenoscopy is essential to assess the type and severity of tissue damage. The main role for endoscopy is to detect metaplastic or premalignant changes complicating gastro-oesophageal reflux, and allow for surveillance. Routine biopsies are potentially useful to increase the diagnostic precision in case of minimal mucosal abnormalities. Management algorithms should include endoscopy to be performed early in the course of disease in most patients, even in the absence of alarm symptoms. Routine use of the Los Angeles classification of oesophagitis and the Prague classification for metaplasia is necessary for a precise description and biopsy sampling. Magnification chromoendoscopy is particularly useful in the hands of experienced endoscopists, whereas novel technologies including confocal laser endomicroscopy may become an important method in specialised centres to optimise the surveillance of premalignant mucosa.

Autofluorescence and narrow band imaging in Barrett's esophagus

This review discusses the application of 2 novel imaging techniques in Barrett's esophagus: autofluorescence imaging and narrow band imaging (NBI). Autofluorescence as well as NBI may help to direct endoscopic therapy for early neoplasia in Barrett's esophagus; their value in daily practice, however, seems to be limited and needs further evaluation.

Endoscopic tri-modal imaging is more effective than standard endoscopy in identifying early-stage neoplasia in Barrett's esophagus

BACKGROUND & AIMS

Endoscopic tri-modal imaging (ETMI) incorporates high-resolution endoscopy (HRE), autofluorescence imaging (AFI), and narrow band imaging (NBI). A recent uncontrolled study found that ETMI improved the detection of high-grade dysplasia (HGD) and early carcinoma (Ca) in Barrett's esophagus (BE). The aim was to compare ETMI with standard video endoscopy (SVE) for the detection of HGD/Ca with the use of a randomized cross-over design.

METHODS

Patients referred for work-up of inconspicuous HGD/Ca were eligible and underwent both SVE and ETMI in randomized order within an interval of 6-12 weeks. During ETMI, inspection with HRE was followed by AFI. Detected lesions were inspected in detail with NBI and biopsied, followed by random biopsies. During SVE, any visible lesion was biopsied followed by random biopsies.

RESULTS

Eighty-seven patients with BE underwent ETMI and SVE. No significant difference was observed in overall histologic yield between ETMI and SVE. ETMI had a significantly higher targeted yield compared with SVE because of AFI. However, the yield of targeted biopsies of ETMI was significantly inferior to the overall yield of SVE. Detailed inspection with NBI reduced the false-positive rate of HRE + AFI from 71% to 48% but misclassified 17% of HGD/Ca lesions as not suspicious.

CONCLUSIONS

ETMI statistically significant improves the targeted detection of HGD/Ca compared with SVE. Subsequent characterization of lesions with NBI appears to be of limited value. At this stage, ETMI cannot replace random biopsies for detection of lesions or targeted biopsies for characterization of lesions in a high-risk population.

Enhanced mucosal imaging

PURPOSE OF REVIEW

The continued application of innovative imaging systems to endoscopic procedures has vastly improved the detection of indiscriminant tissue anomalies. This article describes the fundamental principles of these technologies and reviews the advances of each over the past 18 months, considering their utility in the diagnosis and surveillance of various gastrointestinal diseases.

RECENT FINDINGS

Through a combination of novel optics, processors and filters, real-time high-resolution contrast endoscopy provides increased visual data without greater procedure duration or difficulty. Optical contrast techniques incorporated into endoscopes, such as narrow band imaging (Olympus), i-Scan (Pentax), and Fujinon Intelligent Chromo Endoscopy, have become standard of care for many endoscopists. These technologies, as well as autofluorescence imaging, potentially improve detection of mucosal abnormalities, serving as 'red flag' tools for the evaluation of wide areas of mucosa. In addition, a number of promising devices allow virtual histology and in-vivo diagnosis, thereby directing biopsies and potentially guiding concurrent interventions. One such technology, confocal laser endomicroscopy, continues to establish its role in clinical practice. Because of inherent shortcomings affecting each modality's sensitivity and specificity, the coupling of various devices, as with endoscopic trimodal imaging, has shown great promise; however, most are not widely available and not definitively proven to be superior to more established techniques. Emerging technologies, including in-vivo molecular tagging, provide a powerful means of detecting disease without reliance on morphologic diagnostic criteria.

SUMMARY

Endoscopy continues to evolve from a field that previously allowed only macroscopic imaging dependent on subsequent pathology to one that allows real-time in-vivo diagnosis. Although the promise of enhanced endoscopic technologies seems limitless, practical and technological considerations slow their adoption into the standard of care.

Endoscopic mucosal resection in the management of esophageal neoplasia: current status and future directions

Endoscopic mucosal resection has expanded the role of the gastroenterologist in the management of esophageal neoplasia from screening and diagnosis to staging and endoscopic treatment. Its rise to prominence is a reflection of the long-identified need to obtain histologic information regarding depth of invasion and neoplastic margins during therapy that previously could not be achieved with ablative techniques. The resultant improvement in diagnosis and staging has allowed for better selection of patients for endoscopic therapy who may be spared invasive surgery. The clinical indications, endoscopic techniques, outcomes, and complications in the management of esophageal neoplasia are reviewed. Training requirements to achieve proficiency in endoscopic mucosal resection as well as potential quality measures to assess competence also are proposed in this review.

Endoscopic techniques for recognizing neoplasia in Barrett's esophagus: which should the clinician use?

PURPOSE OF REVIEW

The key to prevention and cure of esophageal adenocarcinoma is the detection and eradication of neoplasia in patients with Barrett's esophagus. Multiple tools and technologies are emerging for this purpose.

RECENT FINDINGS

A detailed white light examination with high-resolution endoscopy and recognition of lesions is paramount. A variety of imaging modalities are being studied for the detection of neoplasia in Barrett's esophagus. Chromoendoscopy, narrow band imaging, and autofluorescence provide a way to target suspicious areas. Confocal endomicroscopy and optical coherence tomography are means to pinpoint imaging to obtain information about the tissue microarchitecture.

SUMMARY

The key to detection of neoplasia is a careful white light examination with high-resolution endoscopy and recognition of lesion characteristics. Additional imaging modalities may enhance targeting of lesions or provide more information at a focused level. Many of these modalities have yet to be validated in prospective randomized, multicenter trials.

Endoscopic imaging for the detection of esophageal dysplasia and carcinoma

Numerous endoscopic imaging modalities have been developed and introduced into clinical practice to enhance diagnostic capabilities. In the past, detection of dysplasia and carcinoma of the esophagus has been dependent on biopsies taken during standard white-light endoscopy. Recent important developments in biophonotics have improved visualization of these subtle lesions sufficiently for cellular details to be seen in vivo during endoscopy. These improvements allow diagnosis to be made in gastrointestinal endoscopy units, thereby avoiding the cost, risk, and time delay involved in tissue biopsy and resection. Chromoendoscopy, narrow-band imaging, high-yield white-light endoscopy, Fujinon intelligent color enhancement, and point enhancement such as confocal laser endomicroscopy are examples of enhanced imaging technologies that are being used in daily practice. This article reviews endoscopic-based imaging techniques for the detection of esophageal dysplasia and carcinoma from the perspective of routine clinical practice.