Narrow-band imaging observation of colorectal lesions using NICE classification to avoid discarding significant lesions

Unifying terminology, reporting, and bowel preparation standards in colon capsule endoscopy: Nyborg Consensus

Background and study aims

Colon capsule endoscopy (CCE) is becoming increasingly popular in Europe. However, development of quality assurance and standardized terminology has not kept pace with clinical integration of this technology. As a result, there are significant variations in reporting standards, highlighting the need for a standardized terminology and framework. We used the RAND process to achieve a consensus of experts to determine the terminology in CCE, bowel cleansing assessment, and quality assurance reporting and future research priorities.

Methods

A panel comprising 14 European CCE experts evaluated 45 statements during the international REFLECT symposium (Nyborg, Denmark) through three survey rounds and face-to-face and virtual discussions in the initial two rounds. Participants anonymously rated statement appropriateness.

Results

Twenty-eight consensus statements were developed. Eight statements focus on consistent terminology for confirming CCE-detected polypoid and inflammatory colonic lesions with colonoscopy. To ensure standardization and quality assurance, 13 mandatory fields were recommended for inclusion in a CCE report. Three endorsed reporting methodologies were suggested, emphasizing prompt notification for suspected malignant findings, recommending a generic disclaimer regarding stomach and small bowel visualization intentions, and establishing reporting timelines at an interdepartmental level based on urgency. Four bowel preparation scale-related statements led to the recommendation to adoptithe Colon Capsule CLEansing Assessment and Reporting (CC-CLEAR) scale as the preferred scale.

Conclusions

This study established a framework for terminology, reporting, and assessment of bowel cleansing for CCE. Future research should focus on optimizing bowel preparation regimens and exploring artificial intelligence applications in CCE.

Resection of Early Colorectal Neoplasms Using Endoscopic Submucosal Dissection: A Retrospective Multicenter Cohort Study

Background: Endoscopic submucosal dissection (ESD) is a reliable method that can replace surgery in the treatment of early colorectal cancer under certain conditions. Aim: The aim of the study was to analyze factors influencing the ESD procedure in early colorectal cancer, with the intention of improving its effectiveness. Patients and Methods: We conducted a multicenter, retrospective cohort study on 214 patients who underwent ESD procedures for early colorectal cancer from January 2016 to October 2023. Results:En bloc resection was achieved in 197 (92.1%) of ESD procedures, R0 resection in 149 (69.6%), and curative resection in 54 (40.9%). The submucosal invasion was classified as level 1 (SM1) in 96 cases (45.3%), level 2 (SM2) in 61 cases (28.8%), and level 3 (SM3) in 36 cases (17%). R0 resection was achieved more often in the rectum-92 (81.4%), compared to the right-24 (64.9%) and left colon-33 (61.1%), p = 0.009. In rectal tumors, R0 resection was achieved in 51 (98.1%) SM1 invasion, 27 (73%) SM2 invasion, and 13 (65%) SM3 invasion (p < 0.001). Lateral and vertical resection margins were positive in 12 (7.7%) and 52 (25.2%) cases, respectively. Vertical resection margins were statistically more often positive in lesions located in the right colon-11 cases (28.9%) and left colon-21 cases (38.9%), than in rectum-20 cases (17.5%); p = 0.010. Complications were found in 32 (15%) cases of ESD procedure-perforation in 12 cases (5.6%) and delayed bleeding in four cases (1.9%). Procedures performed in the right colon were associated with a significantly higher risk of any complications (30%) and perforations (15%) than those performed in the rectum (10.3% and 2.6%) or the left colon (13.8% and 5.2%; p = 0.016; p = 0.015), respectively. Conclusions: ESD for early colon cancer is a viable strategy due to its effectiveness and low complication rate. The ESD technique performed in the rectum yields the best results; however, in the right colon, it still requires careful attention.

Narrow band imaging: Important tool for early diagnosis, management, and improved outcomes in gastrointestinal lesions

BACKGROUND

Narrow band imaging-magnifying endoscopy (NBI-ME) is used to identify changes in mucosal or vascular pattern observed on GI endoscopy in real time on the basis of optical image enhancement.It has a significant role in early detection of dysplasia, premalignant, and Malignant lesions along with its depth of invasion.

MATERIALS AND METHODS

Upper and lower GI endoscopy performed in 1742 patients who presented with gastrointestinal symptoms at this tertiary center over 5 years out of which 1623 were evaluated with both NBI-ME and histopathology. Real time endoscopic assessment was performed. Targeted biopsies were taken for comparative analysis.

RESULTS

Of the 1742 patients, 119 were excluded from the study. 807 underwent upper GI endoscopy and 816 underwent lower GI endoscopy. Mean age of presentation was 38 +/- 2.7 years. Sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of NBI-ME for neoplastic esophageal lesions were 96.3%, 90.6%, 91.1%, 96.03%, respectively. For Barrett's esophagus it was 95.4%, 90.7%, 86.1%, and 90.7%; For gastric neoplastic lesions the values were 96.1%, 91.04%, 83.8%, and 97.9%. For colorectal it was 96.7%, 91.3%, 88.0%, and 97.7%. Overall sensitivity, specificity, PPV, and NPV of NBI-ME for neoplastic lesions (both upper and lower GI) were 96.2%, 91.0%, 96.2%, and 97.2%. Of the 1623 patients, 951 received medical management with regular surveillance and 672 patients with high-grade dysplasia, premalignant, and malignant conditions underwent interventions in form of either endoscopy or surgery.

CONCLUSION

NBI-ME has a greater role and can be considered as an effective tool in making early diagnosis and guiding optimum treatment.

Endoscopic Assessment of Local Resectability of Colorectal Malignancies

Background

The endoscopic assessment of colorectal malignancies primarily aims at deciding on the local resectability. Local resectability is defined by the risk of lymphonodal metastasis.

Summary

The gross morphology as well as the surface and vessel patterns provide valuable information prior to endoscopic resection. Various classifications have been standardized to assist endoscopists during endoscopic assessment.

Key Message

The macroscopic assessment of colorectal malignancies should include the Paris and laterally spreading tumor (LST) classification as well as chromoendoscopic assessments such as Kudo's pit pattern and the Japanese NBI Expert Team classifications to describe the vessel and surface patterns.

Improving the management and outcomes of complex non-pedunculated colorectal polyps at a regional hospital in British Columbia

BACKGROUND

Colorectal cancer arises from precancerous lesions, primarily adenomatous and serrated polyps. Some polyps pose significant technical endoscopic challenges due to their size, location, and/or morphology. A standardized protocol for documentation and management of these polyps can optimize clinical outcomes.

METHODS

A Quality Improvement project compared patients with a complex polyp (non-pedunculated, > 2 cm), for 12 months prior and 12 months after protocol introduction. Documentation and polyp management details were compared pre- and post-implementation using the Chi-square test.

RESULTS

69 patients were diagnosed with complex polyps prior to the protocol introduction and 72 after. 79% (112/141) of patients underwent endoscopic mucosal resections (EMR) locally, and 14.9% (21/141) underwent surgery locally. After protocol introduction, there was significant improvement in documentation of suspicious appearing polyps (21.7% to 47.2%, P = 0.001), luminal circumference (14.5% to 34.7%, P = 0.005), and management plans (87.0% to 97.2%, P = 0.023); other elements of documentation were similar. The number of patients reviewed at multidisciplinary conference (MDC) increased from 1 to 61% (P < 0.005). Patients rebooked in a 1 h endoscopy time slot increased from 19 to 58% (P < 0.005), as did specific consent for EMR from 22 to 57% (P < 0.005). Among patients with polyps 3 cm or greater (23 pre, 36 post), MDC review increased from 4 to 67% (P < 0.005), primary polypectomy decreased from 72 to 23% (P = 0.001), patients rebooked in a double endoscopy slot increased from 33 to 75% (P = 0.005), and specific consent increased from 39 to 75% (P = 0.014). There were less polyp recurrences (12/42 pre and 1/50 post) among the post-protocol cohort (P < 0.001).

CONCLUSIONS

The introduction of a formalized protocol for complex polyp adjudication and management has led to improved documentation, multidisciplinary discussion, and optimal complex polyp management with dedicated time for EMR, particularly for polyps over 3 cm. There is room for improvement, and this can be approached in a collaborative manner.

Utility of narrow-band imaging with or without dual focus magnification in neoplastic prediction of small colorectal polyps: a Vietnamese experience

BACKGROUND/AIMS

Accurate neoplastic prediction can significantly decrease costs associated with pathology and unnecessary colorectal polypectomies. Narrow band imaging (NBI) and dual-focus (DF) mode are promising emerging optical technologies for recognizing neoplastic features of colorectal polyps digitally. This study aimed to clarify the clinical usefulness of NBI with and without DF assistance in the neoplastic prediction of small colorectal polyps (<10 mm).

METHODS

This cross-sectional study included 530 small colorectal polyps from 343 consecutive patients who underwent colonoscopy at the University Medical Center from September 2020 to May 2021. Each polyp was endoscopically diagnosed in three successive steps using white-light endoscopy (WLE), NBI, and NBI-DF and retrieved for histopathological assessment. The diagnostic accuracy of each modality was evaluated with reference to histopathology.

RESULTS

There were 295 neoplastic polyps and 235 non-neoplastic polyps. The overall accuracies of WLE, WLE+NBI, and WLE+NBI+NBI-DF in the neoplastic prediction of colorectal polyps were 70.8%, 87.4%, and 90.8%, respectively (p<0.001). The accuracy of WLE+NBI+NBI-DF was significantly higher than that of WLE+NBI in the polyp size ≤5 mm subgroup (87.3% vs. 90.1%, p<0.001).

CONCLUSION

NBI improved the real-time neoplastic prediction of small colorectal polyps. The DF mode was especially useful in polyps ≤5 mm in size.

Endoscopic and pathological characteristics of de novo colorectal cancer: Retrospective cohort study

BACKGROUND

Endoscopy has rapidly developed in recent years and has enabled further investigation into the origin and features of intestinal tumors. The small size and concealed position of these tumors make it difficult to distinguish them from nonneoplastic polyps and carcinoma in adenoma (CIA). The invasive depth and metastatic potential determine the operation regimen, which in turn affects the overall survival and distant prognosis. The previous studies have confirmed the malignant features and clinicopathological features of de novo colorectal cancer (CRC).

AIM

To provide assistance for diagnosis and treatment, but the lack of a summary of endoscopic features and assessment of risk factors that differ from the CIA prompted us to conduct this retrospective study.

METHODS

In total, 167 patients with small-sized CRCs diagnosed by endoscopy were reviewed. The patients diagnosed as advanced CRCs and other malignant cancers or chronic diseases that could affect distant outcomes were excluded. After screening, 63 cases were excluded, including 33 de novo and 30 CIA cases. Patient information, including their follow-up information, was obtained from an electronic His-system. The characteristics between two group and risk factors for invasion depth were analyzed with SPSS 25.0 software.

RESULTS

Nearly half of the de novo CRCs were smaller than 1 cm (n = 16, 48.5%) and the majority were located in the distal colon (n = 26, 78.8%). The IIc type was the most common macroscopic type of de novo CRC. In a Pearson analysis, the differential degree, Sano, JNET, and Kudo types, surrounding mucosa, and chicken skin mucosa (CSM) were correlated with the invasion depth (P < 0.001). CSM was a significant risk factor for deep invasion and disturbed judgment of endoscopic ultrasound. A high degree of tumor budding and tumor-infiltrating lymphocytes are accompanied by malignancy. Finally, de novo CRCs have worse outcomes than CIA CRCs.

CONCLUSION

This is the first comprehensive study to analyze the features of de novo CRCs to distinguish them from nonneoplastic polyps. It is also the first study paying attention to CSM invasive depth measurement. This study emphasizes the high metastatic potential of de novo CRCs and highlights the need for more research on this tumor type.

JAG consensus statements for training and certification in flexible sigmoidoscopy

INTRODUCTION

Joint Advisory Group (JAG) certification in endoscopy is awarded when trainees attain minimum competency standards for independent practice. A national evidence-based review was undertaken to update standards for training and certification in flexible sigmoidoscopy (FS).

METHODS

A modified Delphi process was conducted between 2019 and 2020 with multisociety representation from experts and trainees. Following literature review and Grading of Recommendations, Assessment, Development and Evaluations appraisal, recommendation statements on FS training and certification were formulated and subjected to anonymous voting to obtain consensus. Accepted statements were peer-reviewed by national stakeholders for incorporation into the JAG FS certification pathway.

RESULTS

In total, 41 recommendation statements were generated under the domains of: definition of competence (13), acquisition of competence (17), assessment of competence (7) and postcertification support (4). The consensus process led to revised criteria for colonoscopy certification, comprising: (A) achieving key performance indicators defined within British Society of Gastroenterology standards (ie, rectal retroversion >90%, polyp retrieval rate >90%, patient comfort <10% with moderate-severe discomfort); (B) minimum procedure count ≥175; (C) performing 15+ procedures over the preceding 3 months; (D) attendance of the JAG Basic Skills in Lower gastrointestinal Endoscopy course; (E) satisfying requirements for formative direct observation of procedural skill (DOPS) and direct observation of polypectomy skill (SMSA level 1); (F) evidence of reflective practice as documented on the JAG Endoscopy Training System reflection tool and (G) successful performance in summative DOPS.

CONCLUSION

The UK standards for training and certification in FS have been updated to support training, uphold standards in FS and polypectomy, and provide support to the newly independent practitioner.

JAG consensus statements for training and certification in colonoscopy

INTRODUCTION

In the UK, endoscopy certification is awarded when trainees attain minimum competency standards for independent practice. A national evidence-based review was undertaken to update and develop standards and recommendations for colonoscopy training and certification.

METHODS

Under the oversight of the Joint Advisory Group (JAG), a modified Delphi process was conducted between 2019 and 2020 with multisociety expert representation. Following literature review and Grading of Recommendations, Assessment, Development and Evaluations appraisal, recommendation statements on colonoscopy training and certification were formulated and subjected to anonymous voting to obtain consensus. Accepted statements were peer reviewed by JAG and relevant stakeholders for incorporation into the updated colonoscopy certification pathway.

RESULTS

In total, 45 recommendation statements were generated under the domains of: definition of competence (13), acquisition of competence (20), assessment of competence (8) and postcertification support (4). The consensus process led to revised criteria for colonoscopy certification, comprising: (1) achieving key performance indicators defined within British Society of Gastroenterology standards (ie, unassisted caecal intubation rate >90%, rectal retroversion >90%, polyp detection rate >15%+, polyp retrieval rate >90%, patient comfort <10% with moderate-severe discomfort); (2) minimum procedure count 280+; (3) performing 15+ procedures over the preceding 3 months; (4) attendance of the JAG Basic Skills in Colonoscopy course; (5) terminal ileal intubation rates of 60%+ in inflammatory bowel disease; (6) satisfying requirements for formative direct observation of procedure skills (DOPS) and direct observation of polypectomy skills (Size, Morphology, Site, Access (SMSA) level 2); (7) evidence of reflective practice as documented on the JAG Endoscopy Training System reflection tool; (8) successful performance in summative DOPS.

CONCLUSION

The UK standards for training and certification in colonoscopy have been updated, culminating in a single-stage certification process with emphasis on polypectomy competency (SMSA Level 2+). These standards are intended to support training, improve standards of colonoscopy and polypectomy, and provide support to the newly independent practitioner.

Mucosal imaging in colon polyps: New advances and what the future may hold

An expanding range of advanced mucosal imaging technologies have been developed with the goal of improving the detection and characterization of lesions in the gastrointestinal tract. Many technologies have targeted colorectal neoplasia given the potential for intervention prior to the development of invasive cancer in the setting of widespread surveillance programs. Improvement in adenoma detection reduces miss rates and prevents interval cancer development. Advanced imaging technologies aim to enhance detection without significantly increasing procedural time. Accurate polyp characterisation guides resection techniques for larger polyps, as well as providing the platform for the "resect and discard" and "do not resect" strategies for small and diminutive polyps. This review aims to collate and summarise the evidence regarding these technologies to guide colonoscopic practice in both interventional and non-interventional endoscopists.

Diagnosis of Depth of Submucosal Invasion in Colorectal Cancer with AI Using Deep Learning

The submucosal invasion depth predicts prognosis in early colorectal cancer. Although colorectal cancer with shallow submucosal invasion can be treated via endoscopic resection, colorectal cancer with deep submucosal invasion requires surgical colectomy. However, accurately diagnosing the depth of submucosal invasion via endoscopy is difficult. We developed a tool to diagnose the depth of submucosal invasion in early colorectal cancer using artificial intelligence. We reviewed data from 196 patients who had undergone a preoperative colonoscopy at the Osaka University Hospital and Osaka International Cancer Institute between 2011 and 2018 and were diagnosed pathologically as having shallow submucosal invasion or deep submucosal invasion colorectal cancer. A convolutional neural network for predicting invasion depth was constructed using 706 images from 91 patients between 2011 and 2015 as the training dataset. The diagnostic accuracy of the constructed convolutional neural network was evaluated using 394 images from 49 patients between 2016 and 2017 as the validation dataset. We also prospectively tested the tool from 56 patients in 2018 with suspected early-stage colorectal cancer. The sensitivity, specificity, accuracy, and area under the curve of the convolutional neural network for diagnosing deep submucosal invasion colorectal cancer were 87.2% (258/296), 35.7% (35/98), 74.4% (293/394), and 0.758, respectively. The positive predictive value was 84.4% (356/422) and the sensitivity was 75.7% (356/470) in the test set. The diagnostic accuracy of the constructed convolutional neural network seemed to be as high as that of a skilled endoscopist. Thus, endoscopic image recognition by deep learning may be able to predict the submucosal invasion depth in early-stage colorectal cancer in clinical practice.

Optical diagnosis by near-focus versus normal-focus narrow band imaging colonoscopy in colorectal polyps based on combined NICE and WASP classification: a randomized controlled trial

Background/Aims

Narrow Band Imaging (NBI) International Colorectal Endoscopic (NICE) and Workgroup Serrated Polyps and Polyposis (WASP) classifications were developed for optical diagnosis of neoplastic and sessile serrated polyps, respectively. Near-focus NBI with NICE combined with WASP criteria for optical diagnosis of colonic polyps has not yet been evaluated. We aimed to compare the accuracy of near-focus NBI (group A) with normal-focus NBI (group B) in real-time optical diagnosis of colorectal polyps using combined NICE and WASP criteria.

Methods

Among 362 patients, 118 with 227 polyps were recruited. Groups A and B included 62 patients with 130 polyps (three lost polyps) and 56 patients with 106 polyps (six lost polyps), respectively. Optical diagnoses were compared with pathological reports.

Results

The accuracy of optical diagnosis of neoplastic polyps in groups A and B was not significantly different (76% vs. 71%, p=0.52). WASP criteria provided all false positive diagnoses of sessile polyps as serrated polyps in 31 (16.2%) patients.

Conclusions

Near-focus NBI was not superior to normal-focus NBI in optical diagnostics of neoplastic polyps using NICE criteria. In our study, WASP classification yielded all false positives in the diagnosis of sessile serrated adenomas/polyps. Routine real-life optical diagnosis of polyps is still unadvisable.

Hybrid argon plasma coagulation-assisted endoscopic mucosal resection for large sessile colon polyps to reduce local recurrence: a prospective pilot study

BACKGROUND

Endoscopic mucosal resection (EMR) of large, sessile colon polyps often results in incomplete resection with subsequent recurrence. The aim of this prospective pilot study was to evaluate the efficacy and safety of a novel technique, hybrid argon plasma coagulation-assisted EMR (hAPC-EMR), to remove large, sessile polyps.

METHODS

40 eligible patients underwent hAPC-EMR for the removal of one or more nonpedunculated colon polyps ≥ 20 mm. Participants were contacted 30 days post-procedure to assess for adverse events and were recommended to return for a surveillance colonoscopy at 6 months to assess for local recurrence.

RESULTS

At the time writing, 32 patients with 35 polyps (median size 27 mm; interquartile range 14.5 mm) resected by hAPC-EMR had undergone the 6-month follow-up colonoscopy. Recurrence rate was 0 % (95 % confidence interval [CI] 0-0) at follow-up. Post-polypectomy bleeding was experienced by three patients (7.5 %; 95 %CI 0.00-0.15), and no patients developed post-polypectomy syndrome.

CONCLUSION

These preliminary results showed 0 % local recurrence rate at 6 months and demonstrated the safety profile of hAPC-EMR. A large, randomized, controlled trial is required to confirm these results.

Development and validation of the linked color imaging classification for endoscopic prediction of colorectal polyp histology

OBJECTIVE

Linked color imaging (LCI) is a recently developed technique that emphasizes differences in mucosal color. In this study we aimed to develop a LCI classification based on the Narrow-band Imaging International Colorectal Endoscopic Classification for predicting colorectal polyp histology and evaluate the validity and performance of the endoscopists in differentiating hyperplastic polyps from adenomas using the LCI classification.

METHODS

A workshop involving six international experts from China and Japan with substantial experience with LCI developed the classification. Three experienced and seven less-experienced endoscopists used the LCI images to predict the histology of polyps independently, recording their degrees of confidence in these predictions before and after completing the training test for the LCI classification.

RESULTS

Of the 50 polyps included, 30 (60.0%) were adenomas. Overall diagnostic accuracy before training was 75.4% (95% confidence interval [CI] 71.4%-79.1%), which increased to 85.2% (95% CI 81.8%-88.2%) after training. After training, the experienced and less-experienced endoscopists achieved an overall accuracy of 87.3% and 84.3% for the prediction of polyp histology. Polyp prediction using the color criterion alone had the highest specificity and positive predictive value, whereas the vessel criterion achieved the highest accuracy and negative predictive value among all three individual LCI criteria. After training, both the experienced and less-experienced endoscopists had high degrees of interobserver agreement.

CONCLUSIONS

We developed and validated the first LCI classification for endoscopic differentiation of adenomas and hyperplastic polyps. The LCI classification significantly improved the diagnostic accuracy of colorectal polyps.

Systematic Review on Optical Diagnosis of Early Gastrointestinal Neoplasia

BACKGROUND

Meticulous endoscopic characterization of gastrointestinal neoplasias (GN) is crucial to the clinical outcome. Hereby the indication and type of resection (endoscopically, en-bloc or piece-meal, or surgical resection) are determined. By means of established image-enhanced (IEE) and magnification endoscopy (ME) GN can be characterized in terms of malignancy and invasion depth. In this context, the statistical evidence and accuracy of these diagnostic procedures should be elucidated. Here, we present a systematic review of the literature.

RESULTS

21 Studies could be found which met the inclusion criteria. In clinical prospective trials and meta-analyses, the diagnostic accuracy of >90% for characterization of malignant neoplasms could be documented, if ME with IEE was used in squamous cell esophageal cancer, stomach, or colonic GN.

CONCLUSIONS

Currently, by means of optical diagnosis, today's gastrointestinal endoscopy is capable of determining the histological subtype, exact lateral spread, and depth of invasion of a lesion. The prerequisites for this are an exact knowledge of the anatomical structures, the endoscopic classifications based on them, and a systematic learning process, which can be supported by training courses. More prospective clinical studies are required, especially in the field of Barrett's esophagus and duodenal neoplasia.

Diagnostic performance of narrow-band imaging international colorectal endoscopic and Japanese narrow-band imaging expert team classification systems for colorectal cancer and precancerous lesions

BACKGROUND

In recent years, two new narrow-band imaging (NBI) classifications have been proposed: The NBI international colorectal endoscopic (NICE) classification and Japanese NBI expert team (JNET) classification. Most validation studies of the two new NBI classifications were conducted in classification setting units by experienced endoscopists, and the application of use in different centers among endoscopists with different endoscopy skills remains unknown.

AIM

To evaluate clinical application and possible problems of NICE and JNET classification for the differential diagnosis of colorectal cancer and precancerous lesions.

METHODS

Six endoscopists with varying levels of experience participated in this study. Eighty-seven consecutive patients with a total of 125 lesions were photographed during non-magnifying conventional white-light colonoscopy, non-magnifying NBI, and magnifying NBI. The three groups of endoscopic pictures of each lesion were evaluated by the six endoscopists in randomized order using the NICE and JENT classifications separately. Then we calculated the six endoscopists’ sensitivity, specificity, accuracy, positive predictive value, and negative predictive value for each category of the two classifications.

RESULTS

The sensitivity, specificity, and accuracy of JNET classification type 1 and 3 were similar to NICE classification type 1 and 3 in both the highly experienced endoscopist (HEE) and less-experienced endoscopist (LEE) groups. The specificity of JNET classification type 1 and 3 and NICE classification type 3 in both the HEE and LEE groups was > 95%, and the overall interobserver agreement was good in both groups. The sensitivity of NICE classification type 3 lesions for diagnosis of SM-d carcinoma in the HEE group was significantly superior to that in the LEE group (91.7% vs 83.3%; P = 0.042). The sensitivity of JNET classification type 2B lesions for the diagnosis of high-grade dysplasia or superficial submucosal invasive carcinoma in the HEE and LEE groups was 53.8% and 51.3%, respectively. Compared with other types of JNET classification, the diagnostic ability of type 2B was the weakest.

CONCLUSION

The treatment strategy of the two classification type 1 and 3 lesions can be based on the results of endoscopic examination. JNET type 2B lesions need further examination.

PICCOLO White-Light and Narrow-Band Imaging Colonoscopic Dataset: A Performance Comparative of Models and Datasets

Colorectal cancer is one of the world leading death causes. Fortunately, an early diagnosis allows for effective treatment, increasing the survival rate. Deep learning techniques have shown their utility for increasing the adenoma detection rate at colonoscopy, but a dataset is usually required so the model can automatically learn features that characterize the polyps. In this work, we present the PICCOLO dataset, that comprises 3433 manually annotated images (2131 white-light images 1302 narrow-band images), originated from 76 lesions from 40 patients, which are distributed into training (2203), validation (897) and test (333) sets assuring patient independence between sets. Furthermore, clinical metadata are also provided for each lesion. Four different models, obtained by combining two backbones and two encoder–decoder architectures, are trained with the PICCOLO dataset and other two publicly available datasets for comparison. Results are provided for the test set of each dataset. Models trained with the PICCOLO dataset have a better generalization capacity, as they perform more uniformly along test sets of all datasets, rather than obtaining the best results for its own test set. This dataset is available at the website of the Basque Biobank, so it is expected that it will contribute to the further development of deep learning methods for polyp detection, localisation and classification, which would eventually result in a better and earlier diagnosis of colorectal cancer, hence improving patient outcomes.

Feasibility of using narrow band imaging international colorectal endoscopic classification for diagnosing colorectal neoplasia in China: A multicenter pilot observational study

OBJECTIVE

We aimed to investigate whether Chinese endoscopists without narrow-band imaging (NBI) experiences could achieve high accuracy in the real-time diagnosis of colorectal polyps using NBI International Colorectal Endoscopic (NICE) classification after web-based training.

METHODS

Altogether 15 endoscopists from five centers with no NBI experiences followed a short, web-based training program on the NICE classification and took web-based test. Their performances were compared with 15 matched experienced endoscopists with no NBI experience who received no NBI training. These 15 trained endoscopists then made real-time diagnoses of colorectal neoplasia. A logistic regression was used to assess potential predictors of diagnostic performance.

RESULTS

Compared with those who received no training, trained endoscopists achieved comparable overall accuracy (85.3% vs 83.1%, P = 0.408) and accuracy at a high-confidence level (87.0% vs 86.0%, P = 0.670), but had a higher confidence rate (86.1% vs 83.7%, P = 0.004) for the diagnosis of neoplasia. Real-time diagnostic accuracy, sensitivity and specificity were 94.3% (95% confidence interval [CI] 91.5%-96.2%), 96.2% (95% CI 93.4%-97.9%) and 85.3% (95% CI 74.8%-92.1%) at high-confidence level. The high-confidence level was the strongest predictor of real-time diagnostic accuracy (odds ratio 12.66, P < 0.001).

CONCLUSIONS

Web-based training can improve the confidence level of endoscopists in accurately diagnosing colorectal polyps using the NICE classification. Chinese endoscopists can achieve high accuracy in diagnosing colorectal neoplasia at a high confidence level (ClinicalTrials ID: NCT02033980).

Long-term follow-up after EMR of large colorectal lesions: metachronous lesions, predictors and surveillance timing

Background: Endoscopic mucosal resection (EMR) is the first-line approach to large colorectal sessile lesions. These patients have been associated with high rates of metachronous lesions (ML), but long-term follow-up (LtFU) data are lacking. We aimed at evaluating the efficacy of an LtFU protocol and analyse the development and risk factors for ML.Methods: A prospectively collected database was analysed. Seventy-six patients submitted to EMR of large colorectal sessile lesions between 2007 and 2013 complied with a specific endoscopic surveillance, consisting of two protocols - initial follow-up (iFU) and LtFU. iFU intended to inspect the mucosectomy scars twice (at 3-6 and 12 months) and remove synchronous lesions (SL). Protocol examinations of LtFU were carried out at the first- and fourth-year post-iFU, aiming to remove ML. Statistical analysis included variables related to patient, index lesion, SL and ML characteristics.Results: Rates of ML were 39.5% and 20.4% at the first- and fourth-year of LtFU, and respectively 11.8% and 3.7% of them were advanced ML. All ML were endoscopically resectable. At univariate analysis, male gender (OR: 2.91; p=.029), the presence of SL (OR 3.86, p=.010) and advanced SL (OR 4.25, p=.006) were risk factors for ML. At multivariate analysis, male gender (p=.031) and advanced SL (p=.006) were significant predictors of ML development.Conclusions: We confirmed the increased risk of ML in patients with large colorectal lesions. A significant number of advanced ML was removed at the first LtFU colonoscopy, probably it should be carried out earlier than currently recommended.

Diagnostic accuracy of i-scan image enhancement for real-time endoscopic diagnosis of small colorectal polyps: a meta-analysis

OBJECTIVE

i-Scan is a digital image enhancement technology, reported to improve diagnostic performance during endoscopy. Previous studies have investigated the accuracy of i-scan for distinguishing between neoplastic and non-neoplastic colonic polyps and suggested diagnostic accuracy close to that required for use in routine clinical practice. The aim of this study was to perform a meta-analysis of the available literature investigating diagnostic accuracy for i-scan optical diagnosis when made in real time for colorectal polyps <10 mm in size.

DATA SOURCES

The databases of Medline, Embase and the Cochrane Library were searched for relevant studies.

METHODS

A bivariate random effects model was used to produce pooled sensitivity and specificity values, and univariable meta-regression was applied for subgroup analysis.

RESULTS

The meta-analysis included 15 studies, and diagnosis of 2817 polyps. The area under the hierarchical summary receiver-operating characteristic curve was 0.96. The pooled sensitivity of i-scan optical diagnosis was 0.92 (95% confidence interval 0.85-0.95). The specificity was 0.90 (95% confidence interval 0.83-0.94).

CONCLUSIONS

This meta-analysis updates and summarizes the available evidence concerning the diagnostic performance of i-scan for small colorectal polyps. An acceptable degree of accuracy was found, showing potential to support a 'resect and discard' strategy for colonic polyps. There was not found to be a significant difference in diagnostic performance between different clinical settings (i.e. teaching hospitals or general hospitals).

Diagnostic performance of magnifying endoscopy with narrow-band imaging in differentiating neoplastic colorectal polyps from non-neoplastic colorectal polyps: a meta-analysis

Colorectal polyps are commonly seen in colonoscopy and the management of neoplastic polyps and non-neoplastic polyps are different. It is necessary to distinguish neoplastic polyps from non-neoplastic polyps in real-time. Therefore, we conducted a meta-analysis to assess the diagnostic accuracy of magnifying endoscopy with narrow-band imaging (ME-NBI) in diagnosing neoplastic colorectal polyps from non-neoplastic colorectal polyps. PubMed and EMBASE were searched for trials that used magnifying endoscopy with ME-NBI for diagnosing neoplastic colorectal polyps. Sixteen articles and 20 fourfold tables were obtained. Sensitivity (Sen), specificity (Spe), positive likelihood ratios (+ LRs), negative likelihood ratios (- LRs) and diagnostic odds ratios (DORs) were calculated. A summary receiver-operating characteristic (SROC) curve was constructed, and the area under the ROC curve (AUC) was calculated. We performed subgroup analyses based on polyp size and assessment criteria: (1) According to data extracted from 20 fourfold tables, the pooled Sen and Spe of ME-NBI for diagnosing neoplastic colorectal polyps < 10 mm were 0.94 (95% CI 0.92-0.95) and 0.76 (95% CI 0.72-0.80),respectively. The pooled Sen and Spe of ME-NBI for diagnosing all neoplastic polyps were 0.98 (95% CI 0.98-0.99) and 0.88 (95% CI 0.85-0.90), respectively. (2) Data pertaining to the following three assessment methods were analysed from 15 fourfold tables: surface pattern (SP), vessel pattern (VP) and the combination of SP and VP. The AUCs for these assessment criteria were 0.9533, 0.9518 and 0.9954, respectively. Conclusions were made that ME-NBI has high diagnostic accuracy in diagnosing neoplastic colorectal polyps based on the combination of SP with VP and is helpful in making real-time diagnoses.

Polyp characterization at colonoscopy: Clinical implications

Although advancements in endoscopic imaging of colorectal mucosa have outstripped the pace of research in the field, the potential clinical applications of these novel technologies are promising. Chief among these is the ability to diagnose colorectal polyps in vivo. This feature appears most applicable to diminuitive polyps, which have very little malignant potential yet represent over 70% of resected polyps. In an ideal application, the capability to predict diminutive hyperplastic polyp histology in vivo precludes the need for excision whereas dimunitive adenomas do require excision, but not necessarily histopathologic analysis if the diagnosis is made in vivo with adequate confidence. However, the vast array of new advanced imaging modalities and polyp classification tools have been difficult to reconcile. We aim to highlight the current status of real-time colorectal polyp diagnosis and identify the barriers that remain to its widespread implementation.

Clinical impact and characteristics of the narrow-band imaging magnifying endoscopic classification of colorectal tumors proposed by the Japan NBI Expert Team

BACKGROUND AND AIMS

The Japan NBI Expert Team (JNET) was established in 2011 and has proposed a universal narrow-band imaging (NBI) magnifying endoscopic classification of colorectal tumors. The aim of this study was to evaluate the clinical usefulness of the JNET classification for colorectal lesions.

METHODS

We analyzed 2933 colorectal lesions, which were diagnosed by NBI magnifying observation before endoscopic treatment or surgery. The colorectal lesions consisted of 136 hyperplastic polyps/sessile serrated polyps (HPs/SSPs), 1926 low-grade dysplasia (LGD), 571 high-grade dysplasia (HGD), 87 superficial submucosal invasive (SM-s) carcinomas, and 213 deep submucosal invasive (SM-d) carcinomas. We evaluated the relationship between the JNET classification and the histologic findings of these lesions.

RESULTS

The sensitivity, specificity, positive and negative predictive values, and accuracy of Type 1 lesions for the diagnosis of HP/SSP were, respectively, 87.5%, 99.9%, 97.5%, 99.4%, and 99.3%; of Type 2A lesions for the diagnosis of LGD were 74.3%, 92.7%, 98.3%, 38.7%, and 77.1%; of Type 2B lesions for the diagnosis of HGD/SM-s carcinoma were 61.9%, 82.8%, 50.9%, 88.2%, and 78.1%; for Type 3 lesions for the diagnosis of SM-d carcinoma were 55.4%, 99.8%, 95.2%, 96.6%, and 96.6%, respectively.

CONCLUSIONS

Types 1, 2A, and 3 of the JNET classification were very reliable indicators for HP/SSP, LGD, and SM-d carcinoma, respectively. However, the specificity and positive predictive value of Type 2B were relatively lower than those of others. Therefore, an additional examination such as pit pattern diagnosis using chromoagents is necessary for accurate diagnosis of Type 2B lesions.

Endoscopic management of mucosal lesions in the gastrointestinal tract

With the increasing role of endoscopy in patient evaluation, more mucosal lesions, including gastric, duodenal and colonic polyps, are encountered during routine examinations. It is imperative for gastroenterologists to become familiar with the endoscopic management of these various gastrointestinal lesions. In this article, various resection techniques will be discussed, including hot/cold forceps polypectomy, hot/cold snare polypectomy, endoscopic mucosal resection, and endoscopic submucosal dissection. The article will also discuss the evidence regarding the efficacy and safety of these techniques and the future direction of endoscopic management of mucosal lesions in the gastrointestinal tract.

Optical diagnosis of colorectal neoplasia: A Western perspective

Optical diagnosis is an emerging paradigm in Western endoscopic practice for the colonoscopic management of diminutive polyps, and includes two complementary clinical strategies: 'resect and discard', in which diminutive high-confidence adenomas are identified, and then removed and discarded without pathological assessment; and 'diagnose and leave', where diminutive high-confidence hyperplastic polyps are identified in the rectosigmoid and then left without resection or biopsy. Like other aspects of colonoscopy performance, adoption of optical diagnosis in Western practice is limited by operator dependency and variation in clinical effectiveness. There is substantial potential for optical diagnosis of colorectal neoplasia during colonoscopy to alleviate the rising costs of health care in the West. However, operator dependence in diagnostic performance together with critical system factors such as informed consent, credentialing, medical legal support and reimbursement incentives must be overcome before optical diagnosis of diminutive lesions is considered for widespread adoption in Western clinical practice.

Improving the utility of colonoscopy: Recent advances in practice

Colonoscopy is a frequently performed diagnostic and therapeutic test and the primary screening tool in several nationalized bowel cancer screening programs. There has been a considerable focus on maximizing the utility of colonoscopy. This has occurred in four key areas: Optimizing patient selection to reduce unnecessary or low yield colonoscopy has offered cost-benefit improvements in population screening. Improving quality assurance, through the development of widely accepted quality metrics for use in individual practice and the research setting, has offered measurable improvements in colonoscopic yield. Significant improvements have been demonstrated in colonoscopic technique, from the administration of preparation to the techniques employed during withdrawal of the colonoscope. Improved techniques to avoid post-procedural complications have also been developed-further maximizing the utility of colonoscopy. The aim of this review is to summarize the recent evidence-based advances in colonoscopic practice that contribute to the optimal practice of colonoscopy.