Superiority of NBI endoscopy to PET/CT scan in detecting esophageal cancer among head and neck cancer patients: a retrospective cohort analysis.

BACKGROUND: Second primary cancer of the esophagus is frequent in head and neck patients, especially in high-risk populations, and has a great impact on the prognosis. Although Positron emission tomography (PET)/computed tomography (CT) scan is commonly conducted in head and neck patients, its ability to detect early esophageal cancer is limited. Narrow-band imaging endoscopy is an accurate and convenient technique for esophageal examination. We aimed to compare PET/CT scan and narrow-band imaging endoscopy for the detection of esophageal cancer in head and neck cancer patients. METHODS: From November 2015 to November 2018, all head and neck cancer patients who underwent both PET/CT scan and narrow-band imaging endoscopy at Changhua Christian Hospital were retrospectively enrolled. Descriptive statistics, receiver operating characteristic curve analysis, logistic regression analysis, independent Student's t-test, and Kaplan-Meier survival analysis were conducted with MedCalc Statistical Software. RESULTS: A total of 147 subjects were included in the analysis; suspicious esophageal lesions were identified by PET/CT scan in 8 (5.44%) and by narrow-band imaging in 35 (23.81%). The final pathologic diagnoses were esophageal squamous cell carcinoma in 10 and high-grade dysplasia in 5. The respective sensitivity, specificity, and area under the curve for detecting suspicious esophageal lesions were 33.33, 97.73%, and 0.655 for PET/CT scan, and 100.0, 84.85%, and 0.924 for narrow-band imaging endoscopy. Hypopharyngeal or laryngeal location of the primary head and neck cancer was the only risk factor for developing second primary esophageal cancer. CONCLUSIONS: PET/CT scan was inferior to narrow-band imaging endoscopy in detecting second primary esophageal cancer in head and neck cancer patients. In addition to PET/CT scan, narrow-band imaging endoscopy should be considered in head and neck patients at high risk for developing second primary esophageal cancer.

Advanced imaging in surveillance of Barrett's esophagus: Is the juice worth the squeeze?

Esophageal cancer is on the rise. The known precursor lesion is Barrett's esophagus (BE). Patients with dysplasia are at higher risk of developing esophageal cancer. Currently the gold standard for surveillance endoscopy involves taking targeted biopsies of abnormal areas as well as random biopsies every 1-2 cm of the length of the Barrett's. Unfortunately studies have shown that this surveillance can miss dysplasia and cancer. Advanced imaging technologies have been developed that may help detect dysplasia in BE. This opinion review discusses advanced imaging in BE surveillance endoscopy and its utility in clinical practice.

Objective validity of the Japan Narrow-Band Imaging Expert Team classification system for the differential diagnosis of colorectal polyps.

BACKGROUND AND AIM: The Japan Narrow-Band Imaging (NBI) Expert Team (JNET) classification is a recently proposed NBI magnifying endoscopy-based classification system for colorectal tumors. Although the usefulness of this system has been reported by JNET experts, its objective validity remains unclear. We tested its validity and usefulness for the diagnosis of colorectal polyps by including colonoscopy experts and non-experts as test participants. METHODS: Forty NBI images of polyps of various JNET types were shown to 22 doctors (11 experts and 11 non-gastrointestinal [GI] trainees) who had not examined the patients. The doctors diagnosed the polyps based solely on the surface and vessel patterns in the magnified images and the JNET classification system. Concordance rates of their diagnoses with the pathological findings of the polyps were determined, and the results for experts and non-GI trainees were compared. RESULTS: Both for colonoscopy experts and non-GI trainees, the JNET classification system was particularly useful for classifying polyps as benign or malignant. Although the accuracy rates for classifying polyps into each JNET type varied among colonoscopy experts, those who were familiar with the JNET classification system were able to diagnose polyps with approximately 90% accuracy. Common mistakes were attributable to misunderstandings of the wording in the JNET classification chart and lack of proper training. CONCLUSION: The JNET classification system is a practical approach for the diagnosis of colorectal polyps. Training is required even for experienced colonoscopists to adopt the system properly. Common pitfalls must be shared among colonoscopists to improve the accuracy of the diagnosis.

Challenges to diagnostic standardization of Barrett's esophagus in Asia.

Barrett's esophagus (BE), a premalignant condition of the lower esophagus, is increasingly prevalent in Asia. However, endoscopic and histopathological criteria vary widely between studies across Asia, making it challenging to assess comparability between geographical regions. Furthermore, guidelines from various societies worldwide provide differing viewpoints and definitions, leading to diagnostic challenges that affect prognostication of the condition. In this review, the authors discuss the controversies surrounding the diagnosis of BE, particularly in Asia. Differences between guidelines worldwide are summarized with further discussion regarding various classifications of BE used, different definitions of gastroesophageal junction used across geographical regions and the clinical implications of intestinal metaplasia in the setting of BE. Although many guidelines recommend the Seattle protocol as the preferred approach regarding dysplasia surveillance in BE, some limitations exist, leading to poor adherence. Newer technologies, such as acetic acid-enhanced magnification endoscopy, narrow band imaging, Raman spectroscopy, molecular approaches and the use of artificial intelligence appear promising in addressing these problems, but further studies are required before implementation into routine clinical practice. The Asian Barrett's Consortium also outlines its ongoing plans to tackle the challenge of standardizing the diagnosis of BE in Asia.

Validation study for development of the Japan NBI Expert Team classification of colorectal lesions.

BACKGROUND AND AIM: The Japan narrow-band imaging (NBI) Expert Team (JNET) was organized to unify four previous magnifying NBI classifications (the Sano, Hiroshima, Showa, and Jikei classifications). The JNET working group created criteria (referred to as the NBI scale) for evaluation of vessel pattern (VP) and surface pattern (SP). We conducted a multicenter validation study of the NBI scale to develop the JNET classification of colorectal lesions. METHODS: Twenty-five expert JNET colonoscopists read 100 still NBI images with and without magnification on the web to evaluate the NBI findings and necessity of the each criterion for the final diagnosis. RESULTS: Surface pattern in magnifying NBI images was necessary for diagnosis of polyps in more than 60% of cases, whereas VP was required in around 90%. Univariate/multivariate analysis of candidate findings in the NBI scale identified three for type 2B (variable caliber of vessels, irregular distribution of vessels, and irregular or obscure surface pattern), and three for type 3 (loose vessel area, interruption of thick vessel, and amorphous areas of surface pattern). Evaluation of the diagnostic performance for these three findings in combination showed that the sensitivity for types 2B and 3 was highest (44.9% and 54.7%, respectively), and that the specificity for type 3 was acceptable (97.4%) when any one of the three findings was evident. We found that the macroscopic type (polypoid or non-polypoid) had a minor influence on the key diagnostic performance for types 2B and 3. CONCLUSION: Based on the present data, we reached a consensus for developing the JNET classification.

Narrow band imaging with near-focus mode for colorectal polyps' characterization.

Conventional white light endoscopy is far from being an ideal tool to detect, characterize, and confirm the nature of colorectal lesions in order to indicate targeted biopsies or polyp resections only when necessary. Minimally invasive imaging techniques have gradually emerged to reveal previously unseen abnormalities to the operator during endoscopic examination. In this respect, technology and applications of narrow band imaging (NBI) are rapidly evolving. Magnification using NBI with near-focus mode has been introduced recently to enable closer examination under the control of a single button. The aim of this article is to offer an in-depth overview of this topic with emphasis on colorectal polyps through a literature review by using PubMed search tools including full-text articles, up-to-date guidelines and recent abstracts with obvious conclusions.

Narrow-band imaging vs. high definition white light for optical diagnosis of small colorectal polyps: a randomized multicenter trial.

BACKGROUND AND STUDY AIM: The aim of the study was to compare the latest narrow-band imaging (NBI) device with high-definition white light (HDWL) endoscopy for accuracy of real-time optical diagnosis of small colorectal polyps. PATIENTS AND METHODS: We conducted a randomized, prospective, multicenter trial at three study sites in Germany. In the NBI arm, endoscopists used NBI for the prediction of polyp pathology on the basis of the NBI International Colorectal Endoscopic classification. In the HDWL arm, NBI was not used for optical classification of polyp histology. The primary outcome was accuracy of optical diagnoses (neoplastic vs. non-neoplastic) in small polyps measuring < 10 mm. Secondary end points included sensitivity and negative predictive value (NPV). RESULTS: A total of 380 patients were randomized 1:1 to either the NBI or HDWL arm. A total of 421 polyps measuring < 10 mm were detected (55.8 % neoplastic, 44.2 % non-neoplastic). Accuracy, sensitivity, and NPV were 73.7 %, 82.4 %, and 75.5 %, respectively, in the NBI arm and 79.2 %, 79.8 %, and 73.4 %, respectively, in the HDWL arm (P = 0.225, P = 0.667, P = 0.765). More polyps were assessed with high confidence in the HDWL arm (82.6 %) than in the NBI arm (73.7 %; P = 0.038). The NPV of the prediction of neoplastic histology in diminutive polyps (≤ 5 mm) rated with high confidence was 90.3 % in the NBI arm. We detected significant differences between the participating study sites in the performance data of predictions. CONCLUSION: The levels of accuracy for real-time prediction of polyp histology (< 10 mm) did not differ between NBI and HDWL for optical diagnosis. Variation in the performance of optical diagnosis was apparent between study centers. TRIAL REGISTRATION: ClinicalTrials.gov (NCT02009774).

Quality of optical diagnosis of diminutive polyps and associated factors.

BACKGROUND AND AIMS: The aim of the study was to identify endoscopist-related and procedural factors that may be associated with the quality of optical diagnosis of diminutive polyps using narrow-band imaging (NBI). METHODS: All subjects who participated in a randomized trial on cap-assisted colonoscopy were eligible for the current study. Optical polyp diagnosis was an a priori outcome of the initial trial. Ten participating endoscopists used NBI to assess all of the diagnosed polyps as adenomatous or non-adenomatous in real-time and provided a degree of diagnostic certainty. The main outcome measures were quality benchmarks of optical diagnosis (negative predictive value [NPV] for diminutive rectosigmoid adenomas, agreement with pathology-based surveillance interval) and assessment of endoscopist-related and procedural factors potentially associated with the quality of optical diagnosis. RESULTS: A total of 1650 polyps were found in 607 patients, with 1311 polyps (79 %) being diminutive, of which 672 (53 %) were adenomatous. The NPV of optical diagnosis for rectosigmoid adenomas was 95 %. The optical diagnosis-based surveillance interval agreed with the pathology-based recommendation in 93 % of patients. Prior experience with image-enhanced endoscopy had no effect on optical diagnosis. Low and high adenoma detectors were not different in achieving the quality benchmarks. Cap-assisted colonoscopy was not associated with quality of optical diagnosis. Quality metrics of optical diagnosis remained similar during the first and second half of the study period. CONCLUSION: High quality optical diagnosis of diminutive polyps can be achieved and sustained by endoscopists previously inexperienced in this practice with minimal training. None of the examined factors appear to affect the quality of optical diagnosis; particularly, endoscopists' adenoma detection was not associated with optical diagnosis.

ASGE Technology Committee systematic review and meta-analysis assessing the ASGE Preservation and Incorporation of Valuable Endoscopic Innovations thresholds for adopting real-time imaging-assisted endoscopic targeted biopsy during endoscopic surveillance of Barrett's esophagus.

BACKGROUND AND AIMS: Endoscopic real-time imaging of Barrett's esophagus (BE) with advanced imaging technologies enables targeted biopsies and may eliminate the need for random biopsies to detect dysplasia during endoscopic surveillance of BE. This systematic review and meta-analysis was performed by the American Society for Gastrointestinal Endoscopy (ASGE) Technology Committee to specifically assess whether acceptable performance thresholds outlined by the ASGE Preservation and Incorporation of Valuable Endoscopic Innovations (PIVI) document for clinical adoption of these technologies have been met. METHODS: We conducted meta-analyses calculating the pooled sensitivity, negative predictive value (NPV), and specificity for chromoendoscopy by using acetic acid and methylene blue, electronic chromoendoscopy by using narrow-band imaging, and confocal laser endomicroscopy (CLE) for the detection of dysplasia. Random effects meta-analysis models were used. Statistical heterogeneity was evaluated by means of I(2) statistics. RESULTS: The pooled sensitivity, NPV, and specificity for acetic acid chromoendoscopy were 96.6% (95% confidence interval [CI], 95-98), 98.3% (95% CI, 94.8-99.4), and 84.6% (95% CI, 68.5-93.2), respectively. The pooled sensitivity, NPV, and specificity for electronic chromoendoscopy by using narrow-band imaging were 94.2% (95% CI, 82.6-98.2), 97.5% (95% CI, 95.1-98.7), and 94.4% (95% CI, 80.5-98.6), respectively. The pooled sensitivity, NPV, and specificity for endoscope-based CLE were 90.4% (95% CI, 71.9-97.2), 98.3% (95% CI, 94.2-99.5), and 92.7% (95% CI, 87-96), respectively. CONCLUSIONS: Our meta-analysis indicates that targeted biopsies with acetic acid chromoendoscopy, electronic chromoendoscopy by using narrow-band imaging, and endoscope-based CLE meet the thresholds set by the ASGE PIVI, at least when performed by endoscopists with expertise in advanced imaging techniques. The ASGE Technology Committee therefore endorses using these advanced imaging modalities to guide targeted biopsies for the detection of dysplasia during surveillance of patients with previously nondysplastic BE, thereby replacing the currently used random biopsy protocols.

Prospective evaluation of a simplified narrowband imaging scoring system for a differential diagnosis of colorectal lesions.

BACKGROUND: Narrowband imaging (NBI) allows characterization of colorectal polyps during endoscopy; however, this is underutilized by most US physicians. The aim of this study was to assess diagnostic performance of an NBI scoring system, based on the NBI international colorectal endoscopic classification, and determine a threshold score yielding the highest negative predictive value (NPV) in the characterization of colorectal neoplasia. METHODS: During colonoscopy, colorectal lesions were scored using the NBI scoring system on a 0-3 scale for NBI findings. All lesions were biopsied or endoscopically removed for pathological examinations. RESULTS: Two hundred and three patients were enrolled, and a total of 156 colorectal lesions were detected in 67 patients. Diagnostic yields under white light mode showed limited diagnostic performance [accuracy 75.6 % (68.9-82.3), sensitivity 69.2 % (58.6-78.3), specificity 84.6 % (73.1-92.0), positive predictive value (PPV) 86.3 % (75.8-92.9), NPV 66.3 % (55.0-76.0)]. Of NBI threshold scores from 1 to 3 for the diagnosis of neoplastic lesion, the score of ≥1 resulted in an accuracy of 88.5 % (83.5-93.5), sensitivity of 97.8 % (91.5-96.6), and specificity of 75.4 % (62.9-84.9), with PPV of 84.8 % (76.1-90.8) and NPV of 96.1 % (85.4-99.3). CONCLUSIONS: The threshold value of ≥1 in this simplified NBI scoring system yielded the highest sensitivity and NPV for non-adenomatous colorectal polyps. This scoring system is simple to apply and is superior to white light endoscopy.

Decision Based on Narrow Band Imaging Cystoscopy without a Referential Normal Standard Rather Increases Unnecessary Biopsy in Detection of Recurrent Bladder Urothelial Carcinoma Early after Intravesical Instillation.

PURPOSE: The purpose of this study was to calculate the operating characteristics of narrowband imaging (NBI) cystoscopy versus traditional white light cystoscopy (WLC) in common clinical scenarios involving suspicion of bladder urothelial carcinoma (UC). MATERIALS AND METHODS: Sixty-three consecutive patients initially underwent WLC and then NBI in a single session for evaluation of microscopic hematuria (group I, n=20), gross hematuria (group II, n=19), and follow-up for prior UC (group III, n=24), by an experienced urologist. All lesions that were abnormal in contrast with adjacent normal mucosa were diagnosed as positive and biopsied. RESULTS: Sixty-six biopsies from 47 patients were performed. Pathologic examination showed 17 cases of UC from 21 sites. While the overall sensitivity of NBI was similar to that of WLC (100% vs. 94.1%), the specificity of NBI was significantly lower than that of WLC (50% vs. 86.9%, p < 0.001), particularly in group III (38.9% vs. 88.9%, p=0.004). Based on identification by NBI only, 23 additional biopsies from 18 cases were performed for identification of one patient with UC, who belonged to group III. In this group, to identify this specific patient, 15 additional biopsies were performed from 10 patients. All seven cases with positive findings from NBI within 2 months after the last intravesical therapy were histologically proven as negative. CONCLUSION: In evaluation for recurrence early after intravesical instillation, the decision based on NBI increased unnecessary biopsy in the absence of an established standard for judging NBI.

Endoscopists can sustain high performance for the optical diagnosis of colorectal polyps following standardized and continued training.

BACKGROUND AND STUDY AIMS: The learning curve for optical diagnosis of colorectal polyps with the narrow-band imaging (NBI) is unknown. To forego histological analysis of diminutive polyps diagnosed optically with high confidence, guidelines recommend ≥ 90 % negative predictive value (NPV) and concordance of ≥ 90 % for surveillance intervals predicted optically and histologically. We aimed to study the learning of optical diagnosis for colorectal polyps. PATIENTS AND METHODS: We studied five endoscopists as part of a randomized multisite trial comparing near-focus and standard-focus views for optical diagnosis. They trained using a computer-based module, followed by 10 real-time colonoscopies with pathology correlation. Endoscopists then optically diagnosed and resected all the polyps found during 558 consecutive colonoscopies, and diagnoses were compared with pathology. Endoscopists repeated the training module at the study midpoint. NPV and concordance of surveillance intervals for diminutive polyps diagnosed optically with high confidence were measured over time. RESULTS: Endoscopists showed high diagnostic performance, with a nonsignificant trend toward higher NPV in the second half of the study. For the 445 polyps in the standard-view arm, the NPV was 88.0 % (95 %CI 75.7 % - 95.5 %) in the first half and 95.8 % (88.3 % - 99.1 %) in the second; P = 0.7. Three endoscopists in the first half and four in the second achieved > 90 % NPV. Concordance of surveillance intervals was identical in the first and second halves at 98.1 % (95 %CI 93.3 % - 99.8 %). CONCLUSIONS: High NPV for the prediction of non-neoplasms with NBI was achieved and maintained in this group of endoscopists who participated in standardized and continued training. Both NPV and surveillance interval agreement indicated high performance in the optical diagnosis of colorectal polyps and exceeded thresholds.

New colonoscope technology: impact on image capture and quality and on confidence and accuracy of endoscopy-based polyp discrimination.

BACKGROUND AND STUDY AIMS: A newer colonoscope series has optical magnification and improvement in image freezing function. We aimed to assess the impact on image capture, image quality, and polyp discrimination. PATIENTS AND METHODS: In consecutive patients undergoing outpatient colonoscopy images of colorectal polyps were taken with Olympus 190 or 180 series instruments. The number of image captures needed to obtain an adequate image, quality of stored images, proportion of polyps with a high confidence estimate of likely histology, and accuracy of interpretations were compared. RESULTS: An acceptable image at the first attempt was obtained in 97.3 % of photos with the 190 device vs. 83.8 % with the 180 instrument (P < 0.001). In the 190 group narrowband imaging (NBI) provided high confidence readings in 9 % more cases than in the 180 group, but did not improve accuracy of polyp categorization. The quality of the stored images was judged better for the 190 device. However, when images that had provided high confidence estimates of polyp histology were re-interpreted later by the original endoscopist, there was agreement with the original interpretation for > 98 % of polyps in both the 180 group and the 190 group. A second endoscopist agreed with the original high confidence interpretations for 90 % of polyps imaged with either the 180 or the 190 scope. CONCLUSION: The new colonoscope had less image blurring, improved subjective quality of stored images, and increased the proportion of high confidence endoscopic estimates of polyp histology, but did not improve accuracy in estimating polyp histology.