Routine image-enhanced endoscopic surveillance for metachronous esophageal squamous cell neoplasms in head and neck cancer patients

BACKGROUND

Esophageal squamous cell neoplasms (ESCNs) are common second primary tumors in patients with head and neck cancer. Image-enhanced endoscopy (IEE) with Lugol chromoendoscopy or magnifying narrow-band imaging both increase the detection of early ESCNs. No evidence-based ESCN surveillance program for head and neck cancer patients without a history of synchronous ESCNs exists. We aimed to evaluate the performance of an IEE surveillance program with magnifying narrow-band imaging endoscopy and Lugol chromoendoscopy.

METHODS

From April 2016, we routinely used IEE with magnifying narrow-band imaging and Lugol chromoendoscopy to evaluate patients with head and neck cancer history. All patients who were negative for ESCNs at the first surveillance endoscopy and received at least 2 IEEs through December 2019 were included. Demographic profiles, clinical data, cancer characteristics, IEE results and pathology reports were analyzed.

RESULTS

A total of 178 patients were included. Only 4 patients (2.2%) developed metachronous ESCNs during follow-up, all of whom received curative resection treatment. The interval for the development of metachronous ESCNs was 477 to 717 days. In multivariate Firth logistic regression and Kaplan‒Meier survival curve analysis, Lugol's voiding lesion type C had an increased risk of esophageal cancer development (adjusted odds ratio = 15.71; 95% confidence interval, 1.33-185.87, p = 0.029). Eight patients died during the study period, and none of them had metachronous ESCNs.

CONCLUSIONS

IEE with magnifying narrow-band imaging and Lugol chromoendoscopy is an effective surveillance program in head and neck cancer patients without a history of ESCNs. Annual surveillance can timely detect early ESCNs with low ESCN-related mortality.

I-scan combined with laryngovideostroboscopy for predicting malignancy in vocal fold leukoplakia

OBJECTIVE

This study evaluated vocal fold leukoplakia using i-scan combined with laryngovideostroboscopy for risk assessment prediction.

METHODS

A total of 141 patients with 218 lesions were enrolled in this study. Morphological characteristics of leukoplakia, assessment of the vascular pattern using i-scan, and vocal fold vibratory function were analyzed.

RESULTS

The number of patients with no, mild, moderate, severe dysplasia, and invasive carcinoma were 68, 40, 17, 46 and 47, respectively. The sensitivity of morphological characteristic, vascular pattern, vibratory function and predictive model were 77.4%, 72%, 69.9%, and 82.8%, respectively. Receiver operating characteristic curve analysis of morphological characteristic, vascular pattern, vibratory function and predictive model were 0.771, 0.824, 0.769, and 0.923, respectively. The results of logistic regression analysis showed that rough morphological types, perpendicular vascular pattern, severe decrease and absence of mucosal waves increased the risk of malignancy (OR = 5.531, 4.973, and 16.992, respectively; P < 0.001).

CONCLUSIONS

I-scan combined with laryngovideostroboscopy can improve the differential diagnosis of low-risk and high-risk vocal fold leukoplakia.

Artificial intelligence-aided diagnostic imaging: A state-of-the-art technique in precancerous screening

BACKGROUND AND AIM

Chromoendoscopy with the use of indigo carmine (IC) dye is a crucial endoscopic technique to identify gastrointestinal neoplasms. However, its performance is limited by the endoscopist's skill, and no standards are available for lesion identification. Thus, we developed an artificial intelligence (AI) model to replace chromoendoscopy.

METHODS

This pilot study assessed the feasibility of our novel AI model in the conversion of white-light images (WLI) into virtual IC-dyed images based on a generative adversarial network. The predictions of our AI model were evaluated against the assessments of five endoscopic experts who were blinded to the purpose of this study with a staining quality rating from 1 (unacceptable) to 4 (excellent).

RESULTS

The AI model successfully transformed the WLI of polyps with different morphologies and different types of lesions in the gastrointestinal tract into virtual IC-dyed images. The quality ratings of the real IC-dyed and AI images did not significantly differ concerning surface structure (AI vs IC: 3.08 vs 3.00), lesion border (3.04 vs 2.98), and overall contrast (3.14 vs 3.02) from 10 sets of images (10 AI images and 10 real IC-dyed images). Although the score depended significantly on the evaluator, the staining methods (AI or real IC) and evaluators had no significant interaction (P > 0.05) with each other.

CONCLUSION

Our results demonstrated the feasibility of employing AI model's virtual IC staining, increasing the possibility of being employed in daily practice. This novel technology may facilitate gastrointestinal lesion identification in the future.

Diagnostic performance of blue laser imaging for early detection of gastric cancer: A systematic review and meta-analysis

BACKGROUND

Gastric cancer (GC) is associated with a significant global health burden and high mortality rates when diagnosed at later stages. The diagnosis often occurs at advanced stages when treatment options are limited and less effective. Early detection strategies are crucial to improving survival rates and outcomes for patients. Blue laser imaging (BLI) is an image-enhanced endoscopy technique that utilizes white light and narrow-band light to detect pathological changes in the mucosal architecture. This study aims at investigating the diagnostic performance of BLI for the detection of GC.

METHODS

A comprehensive search was conducted across multiple databases from inception until March 2023. Studies assessing the diagnostic efficacy of BLI for GC detection were included. The sensitivity, specificity and accuracy of BLI were calculated using pooled proportions and 95% confidence intervals (CI) with a random-effects model. Heterogeneity among the included studies was assessed using the I2 statistic.

RESULTS

Six studies were included in the pooled analysis. There were 708 patients with 380 GC lesions. Most of the lesions involved the lower two-thirds of the stomach. The pooled performance metrics of BLI for GC detection were as follows: sensitivity of 91.9% (95% CI 83.3-96.3%; I2 = 82.3%), specificity of 93.4% (95% CI 82.0-97.8%; I2 = 87.9%) and accuracy of 95.4% (95% CI 72.6-99.8%; I2 = 73.6%).

CONCLUSION

BLI demonstrates high diagnostic efficacy for the detection of GC. BLI can be a valuable tool in clinical practice. However, large-scale, randomized controlled studies are needed to further establish the role of BLI in routine clinical practice for GC detection.

Simultaneous detection of Helicobacter pylori infection comparing between white light and image-enhanced endoscopy

BACKGROUND

Helicobacter pylori (H. pylori) is associated with gastric cancer. Early and accurate diagnosis of H. pylori infection can reduce risk of gastric cancer. Conventional white light imaging (WLI) and image-enhanced endoscopic (IEE) techniques such as narrow-band imaging (NBI), linked color imaging (LCI) and blue laser imaging (BLI) plays pivotal role in H. pylori diagnosis. This study aimed to determine diagnostic performance of real-time endoscopy between WLI and other IEE techniques for diagnosis of H. pylori infection.

METHODS

This prospective study compared endoscopic images by gastroscopy using WLI and IEE techniques (LCI, Magnifying-BLI, and Magnifying-NBI) at Thammasat University Hospital, Thailand between January 2020, and July 2021. All participants underwent gastroscopy. Three biopsies at gastric antrum and two biopsies at body were obtained for H.pylori diagnosis. H. pylori infection was defined as a positive test of either one of the following tests: rapid urease test, histopathology, H. pylori culture.

RESULTS

Of 167 dyspeptic patients undergoing gastroscopy, 100 were enrolled in this study. Overall H. pylori infection was 40%. Patients had the mean age of 59.1 years and 53% were males. Enlarged gastric folds and antral nodularity can predict H. pylori infection with 100% PPV, while fundic gland polyps and red streak provided 100% PPV for exclusion of H. pylori infection on WLI. Sensitivity, specificity, PPV, NPV and accuracy for diagnosis of H. pylori infection for WLI were 80%, 71.7%, 65.3%, 84.3% and 75% respectively, while those for LCI were 90%, 70%, 66.7%, 91.3% and 78% respectively. M-NBI and M-BLI endoscopy demonstrated elongated pits in H. pylori-positive patients. Sensitivity, specificity, PPV, NPV and accuracy for M-BLI were 95%, 80%, 76%, 96% and 86% respectively, whereas those for M-NBI were 92.5%, 86.7%, 82.2%, 94.6% and 89% respectively. Sensitivity of M-BLI was better than WLI, while sensitivities of LCI and M-NBI were also numerically higher than WLI without statistical difference (M-BLI 95%vs.WLI 80%, p = 0.03; M-NBI 92.5%vs.WLI 80%, p = 0.13; LCI 90%vs.WLI 80%, p = 0.22). Sensitivities of all IEE modes were not different from one another (LCI 90%vs.M-BLI 95%, p = 0.50; LCI 90%vs.M-NBI 92.5%, p = 1.00, M-BLI 95%vs.M-NBI 92.5%, p = 1.00).

CONCLUSIONS

M-BLI significantly improved sensitivity of real-time endoscopic diagnosis of H. pylori infection compared with WLI. Enlarged gastric folds and antral nodularity could be reliable predictors for H. pylori infection, while fundic gland polyps and red streak could be important endoscopic findings for H. pylori-negative mucosa.

Recent Progress of Image-Enhanced Endoscopy for Upper Gastrointestinal Neoplasia and Associated Lesions

BACKGROUND

The main therapeutic modality of early upper gastrointestinal neoplasms has shifted from surgery to endoscopic therapy. The role of endoscopy has also expanded not only for more accurate diagnosis of neoplasms but also for the determination of extent and depth of neoplasms with a combination of multiple electronically modified images acquired with image-enhanced endoscopy (IEE) for assessing the feasibility of endoscopic treatment.

SUMMARY

These IEE with or without magnifying endoscopy including narrow-band imaging, blue laser imaging, and linked color imaging (LCI) using narrow-band light have greatly changed the diagnosis for upper gastrointestinal neoplasms. These modalities produce high color contrast between cancer and surrounding mucosa at distant views and clear visualization of surface and vessels at close-up observations. LCI shows purple color of intestinal metaplasia (IM) distinct from other inflammatory gastric mucosae and facilitates the recognition of early gastric cancers often surrounded by IM. Recently, ultrathin endoscopy has provided high-resolution images similar to standard-caliber endoscopy. In addition, these advanced IEEs that integrate computer-assisted artificial intelligence systems are marked and will improve our diagnostic performance for neoplasia in the future.

KEY MESSAGE

New IEE with sufficient brightness and color contrast has increasingly been used based on accumulated evidence for early and accurate detection of neoplastic lesions. We provide recent articles relevant to endoscopic diagnosis with IEE on esophageal, gastric, and duodenal neoplasms. Endoscopic equipment that integrates artificial intelligence support system is now being introduced into routine clinical use and is expected to enhance early detection of neoplastic lesions.

Current status of image-enhanced endoscopy in inflammatory bowel disease

In inflammatory bowel disease (IBD), chronic inflammation leads to unfavorable clinical outcomes and increases the risk of developing colorectal neoplasm (CRN); thereby highlighting the importance of endoscopically evaluating disease activity as well as detecting and characterizing CRN in patients with IBD. With recent advances in image-enhanced endoscopic (IEE) technologies, especially virtual chromoendoscopy (VCE) platforms, this review discusses state-of-the-art IEE techniques and their applicability in assessing disease activity and surveillance colonoscopy in patients with IBD. Among various IEE, VCE demonstrated the capacity to identify quiescent disease activity. And endoscopic remission defined by the new scoring system using VCE platform better predicted clinical outcomes, which may benefit the tailoring of therapeutic strategies in patients with IBD. High-definition dye-chromoendoscopy (HD-DCE) is numerically superior to high-definition white light endoscopy (HD-WLE) in detecting CRN in IBD; however, discrepancy is observed in the statistical significance. VCE showed comparable performance in detecting dysplasia to HD-WLE or DCE and potential for optical diagnosis to differentiate neoplastic from nonneoplastic lesions during surveillance colonoscopy. Applying these novel advanced IEE technologies would provide opportunities for personalized medicine in IBD and optimal treatment of CRN in patients with IBD.

Efficacy of image-enhanced endoscopy for colorectal adenoma detection: A multicenter, randomized trial

BACKGROUND

Improved adenoma detection at colonoscopy has decreased the risk of developing colorectal cancer. However, whether image-enhanced endoscopy (IEE) further improves the adenoma detection rate (ADR) is controversial.

AIM

To compare IEE with white-light imaging (WLI) endoscopy for the detection and identification of colorectal adenoma.

METHODS

This was a multicenter, randomized, controlled trial. Participants were enrolled between September 2019 to April 2021 from 4 hospital in China. Patients were randomly assigned to an IEE group with WLI on entry and IEE on withdrawal (n = 2113) or a WLI group with WLI on both entry and withdrawal (n = 2098). The primary outcome was the ADR. The secondary endpoints were the polyp detection rate (PDR), adenomas per colonoscopy, adenomas per positive colonoscopy, and factors related to adenoma detection.

RESULTS

A total of 4211 patients (966 adenomas) were included in the analysis (mean age, 56.7 years, 47.1% male). There were 2113 patients (508 adenomas) in the IEE group and 2098 patients (458 adenomas) in the WLI group. The ADR in two group were not significantly different [24.0% vs 21.8%, 1.10, 95% confidence interval (CI): 0.99-1.23, P = 0.09]. The PDR was higher with IEE group (41.7%) than with WLI group (36.1%, 1.16, 95%CI: 1.07-1.25, P = 0.01). Differences in mean withdrawal time (7.90 ± 3.42 min vs 7.85 ± 3.47 min, P = 0.30) and adenomas per colonoscopy (0.33 ± 0.68 vs 0.28 ± 0.62, P = 0.06) were not significant. Subgroup analysis found that with narrow-band imaging (NBI), between-group differences in the ADR, were not significant (23.7% vs 21.8%, 1.09, 95%CI: 0.97-1.22, P = 0.15), but were greater with linked color imaging (30.9% vs 21.8%, 1.42, 95%CI: 1.04-1.93, P = 0.04). the second-generation NBI (2G-NBI) had an advantage of ADR than both WLI and the first-generation NBI (27.0% vs 21.8%, P = 0.01; 27.0% vs 21.2.0%, P = 0.01).

CONCLUSION

This prospective study confirmed that, among Chinese, IEE didn’t increase the ADR compared with WLI, but 2G-NBI increase the ADR.

Comparison Trial between I-SCAN-Optical Enhancement and Chromoendoscopy for Evaluating the Horizontal Margins of Gastric Epithelial Neoplasms

Background/Aims

Endoscopic submucosal dissection is a widely used treatment for gastric epithelial neoplasms. Accurate delineation of the horizontal margins is necessary for the complete resection of gastric epithelial neoplasms. Recently, image-enhanced endoscopy has been used to evaluate horizontal margins of gastric epithelial neoplasms. The aim of this study was to investigate whether I-SCAN-optical enhancement (I-SCAN-OE) is superior to chromoendoscopy in evaluating the horizontal margin of gastric epithelial neoplasms.

Methods

This was a multicenter, prospective, and randomized trial. The participants were divided into two groups: I-SCAN-OE and chromoendoscopy. For both groups, we first evaluated the horizontal margins of early gastric cancer or high-grade dysplasia using white-light imaging, and then evaluated, the horizontal margins using I-SCAN-OE or chromoendoscopy. We devised a unique scoring method based on the pathological results obtained after endoscopic submucosal dissection to accurately evaluate the horizontal margins of gastric epithelial neoplasms. The delineation scores of both groups were compared, as were the ratios of positive/negative horizontal margins.

Results

In total, 124 patients were evaluated for gastric epithelial neoplasms, of whom 112 were enrolled in the study. A total of 112 patients participated in the study, and 56 were assigned to each group (1:1). There was no statistically significant difference in the delineation scores between the groups (chromoendoscopy, 7.80±1.94; I-SCAN-OE, 8.23±2.24; p=0.342).

Conclusions

I-SCAN-OE did not show superiority over chromoendoscopy in delineating horizontal margins of gastric epithelial neoplasms.

Possible Role of Image-Enhanced Endoscopy in the Evaluation of Mucosal Healing of Ulcerative Colitis

BACKGROUND

Mucosal healing (MH) is recognized as a therapeutic target in ulcerative colitis (UC) because of evidence that it is associated with favorable clinical outcomes. Current endoscopic assessment of MH by conventional white-light endoscopy is subject to several important clinical issues including the subjective nature of assessment, intra- and interobserver variability, and persistent microscopic inflammation, even in mucosa it was observed as quiescent on conventional endoscopy.

SUMMARY

Advances in image-enhancement technologies enable the provision of high-contrast images that emphasize the mucosal structures, blood vessel patterns, and color tones of the intestinal mucosa, and recently, several image-enhanced endoscopy (IEE) techniques have become available for the assessment of MH in UC. Narrow-band imaging and dual-red imaging facilitate visualization of mucosal vascular structures, which is useful for detecting minor inflammation and predicting relapse because of the capturing of information on incomplete vascular regeneration in patients with UC. Linked-color imaging (LCI) is optimized to emphasize the redness of the mucosa and blood vessels, and is superior for depicting subtle color changes arising from mucosal inflammation. LCI could possibly be used to stratify UC patients with MH on conventional endoscopy. Autofluorescence imaging and i-scan can also depict subtle histological changes underlying the healing of mucosa in UC, revealing them as simple color changes.

KEY MESSAGES

Accumulating evidence suggests that IEE techniques could overcome current unmet needs in the endoscopic assessment of MH in UC and contribute to improving therapy based on treat-to-target strategies.

Current status and future perspective of linked color imaging for gastric cancer screening: a literature review

Screening endoscopy has advanced to facilitate improvements in the detection and prognosis of gastric cancer. However, most early gastric cancers (EGCs) have subtle morphological or color features that are difficult to detect by white-light imaging (WLI); thus, even well-trained endoscopists can miss EGC when using this conventional endoscopic approach. This review summarizes the current and future status of linked color imaging (LCI), a new image-enhancing endoscopy (IEE) method, for gastric screening. LCI has been shown to produce bright images even at a distant view and provide excellent visibility of gastric cancer due to high color contrast relative to the surrounding tissue. LCI delineates EGC as orange-red and intestinal metaplasia as purple, regardless of a history of Helicobacter pylori (Hp) eradication, and contributes to the detection of superficial EGC. Moreover, LCI assists in the determination of Hp infection status, which is closely related to the risk of developing gastric cancer. Transnasal endoscopy (ultra-thin) using LCI is also useful for identifying gastric neoplastic lesions. Recently, several prospective studies have demonstrated that LCI has a higher detection ratio for gastric cancer than WLI. We believe that LCI should be used in routine upper gastrointestinal endoscopies.

Image-enhanced endoscopy for real-time differentiation between hyperplastic and fundic gland polyps in the stomach

BACKGROUND

Fundic gland polyps (FGP) of stomach are benign, while some hyperplastic polyps (HP) may harbor dysplasia or malignancy. Conventional white light endoscopy (WLE) cannot reliably distinguish FGP from HP. We investigated the role of image-enhanced endoscopy in differentiating FGP from HP.

METHODS

Patients with gastric polyps were recruited prospectively. The characteristics of the polyps were assessed using WLE and magnification narrow band imaging (mNBI). The microsurface, intervening space (IS), and microvascular (V) features of polyps were evaluated on mNBI. The pattern characteristic of FGP and HP were determined. Histopathology of polyps was the gold standard for diagnosis. Finally, in the validation phase, five endoscopists applied the characteristic features identified in this study to predict the type of gastric polyp and their performance was assessed.

RESULTS

Forty-five patients with a total of 70 gastric polyps (HP-46, FGP-24) were included in this study. On mNBI, the pattern characteristic of HP included peripheral curved type of white structures forming large circular/villous loops (microsurface), enlarged intervening space, and microvessels appearing as dark patches in the intervening space (p<0.001 vs. FGP). These were noted in 95.7% HP. In contrast, 95.8% FGP had a pattern characterized by dotted/elliptical/tubular white structures (microsurface), normal width of intervening space, and microvessels surrounding the white structures in a network pattern. This IS-V pattern classification had an accuracy of >90% in the validation phase with intra-class correlation coefficient of 0.95. The accuracy of mNBI was higher than WLE (97.1% vs. 67%) in predicting the type of gastric polyp.

CONCLUSIONS

Image-enhanced endoscopy with mNBI (IS-V pattern) performs very well in differentiating HP from FGP.

Clinical outcome of the delineation-without-negative-biopsy strategy in magnifying image-enhanced endoscopy for identifying the extent of differentiated-type early gastric cancer

BACKGROUND

The histologic evaluation of biopsy samples collected from the surrounding mucosa has conventionally been used to determine the horizontal extent of early gastric cancer. Recently, optical delineation using magnifying image-enhanced endoscopy (IEE) has been considered an alternative method to histologic evaluation. This study aimed to assess the clinical outcome and efficacy of this method in identifying cancer margins.

METHODS

Overall, 921 patients with 1018 differentiated-type early gastric tumors who underwent endoscopic submucosal dissection (ESD) were examined. Before ESD, the lesions were classified based on whether they have clear or unclear margins on magnifying IEE. When the lesions had clear margins, the marking dots were placed outside the margins without a negative biopsy. Successful delineation was defined as lesions with clear margins and accurate delineation based on histopathological examination. The primary outcome was the accuracy of optical delineation without a negative biopsy compared with histopathological diagnosis. Moreover, the clinicopathological factors associated with an unsuccessful delineation were assessed.

RESULTS

Of 1018 lesions, 820 had a clear margin and 198 an unclear margin. Of 820 lesions with a clear margin, 817 and 3 had an accurate and inaccurate delineation, respectively, according to the histological examination. Accordingly, the accuracy rate of optical delineation was 99.6% (817/820). The significant independent factors associated with an unsuccessful delineation were absence of Helicobacter pylori infection after eradication, tumor size > 20 mm, and moderate differentiation.

CONCLUSIONS

Optical delineation may be an alternative method to histological evaluation in lesions with a clear margin on magnifying IEE.

Comparison of blue laser imaging and narrow band imaging for the differentiation of diminutive colorectal polyps: A randomized controlled trial

BACKGROUND

To compare the diagnostic efficacy of blue laser imaging (BLI)- bright and narrow band imaging (NBI) modes of image enhanced endoscopy (IEE) in differentiating neoplastic and non-neoplastic lesions of diminutive colorectal polyps.

METHODS

We conducted a prospective randomized controlled trial from September 2015 to July 2016. The participants were randomly assigned (1:1) for colonoscopy with polyp classification under NBI or BLI-bright mode without magnification. Histopathologic diagnosis was used as the gold standard.

RESULTS

Three hundred and twenty-four diminutive polyps in 164 patients were included for analysis (BLI: 162 polyps in 73 patients, NBI: 162 polyps in 91 patients). These polyps were located at colon proximal to sigmoid (61.1 and 58.0%) and rectosigmoid colon (38.9 and 42.0%) in the BLI and NBI groups, respectively. Most polyps (71.9%) were adenomatous with one malignant polyp (0.3%). BLI achieved 86.4% accuracy, 98.3% sensitivity, 55.6% specificity, 85.2% positive predictive value (PPV), and 92.6% negative predictive value (NPV), similar to NBI which exhibited 90.1% accuracy, 99.1% sensitivity, 67.4% specificity, 88.5% PPV, and 96.9% NPV in the diagnosis of adenomatous polyps. Based on the location of the polyp, both modes of IEE provided ≥ 95% NPV for diagnosis of adenomatous polyps at the rectosigmoid colon.

CONCLUSIONS

BLI-bright and NBI modes of IEE have similar accuracy in differentiation between neoplastic and non-neoplastic lesions of diminutive polyps. Both modes provided ≥ 90% NPV which allows for the adaptation of the American Society of Gastrointestinal Endoscopy "diagnose-and-leave" recommended strategy for diminutive polyps at the rectosigmoid colon.

Peroral Pancreatoscopy with Videoscopy and Narrow-Band Imaging in Intraductal Papillary Mucinous Neoplasms with Dilatation of the Main Pancreatic Duct

Background/Aims

Endoscopic evaluation of intraductal papillary mucinous neoplasms (IPMNs) is useful in determining whether the lesions are benign or malignant. This study aimed to examine the usefulness of peroral pancreatoscopy (POPS) in determining the prognosis of IPMNs.

Methods

POPS with videoscopy was performed using the mother–baby scope technique. After surgery, computed tomography/magnetic resonance cholangiopancreatography or ultrasonography and blood tests were performed every 6 months during the follow-up.

Results

A total of 39 patients with main pancreatic duct (MPD)–type IPMNs underwent POPS using a videoscope, and the protrusions in the MPD were observed in 36 patients. The sensitivity and specificity of cytology/biopsy performed at the time of POPS were 85% and 87.5%, respectively. Of 19 patients who underwent surgery, 18 (95%) patients had negative surgical margins and 1 (5%) patient had a positive margin.

Conclusions

In IPMNs with dilatation of the MPD, POPS is considered effective if the lesions can be directly observed. The diagnosis of benign and malignant lesions is possible depending on the degree of lesion elevation. However, in some cases, slightly elevated lesions may increase in size during the follow-up or multiple lesions may be simultaneously present; therefore, careful follow-up is necessary.

Visibility of the bleeding point in acute rectal hemorrhagic ulcer using red dichromatic imaging: A case report

BACKGROUND

Red dichromatic imaging (RDI) is a novel image-enhanced endoscopy expected to improve the visibility of the bleeding point. However, it has not been thoroughly investigated.

CASE SUMMARY

A 91-year-old man developed a sudden massive hematochezia and underwent emergent colonoscopy. An ulcer with pulsatile bleeding was found on the lower rectum. Due to massive bleeding, the exact location of the bleeding point was not easy to detect with white light imaging (WLI). Upon switching to RDI, the bleeding point appeared in deeper yellow compared to the surrounding blood. Thus, RDI enabled us for easier recognition of the bleeding point, and hemostasis was achieved successfully. Furthermore, we reviewed endoscopic images and evaluated the color difference between the bleeding point and surrounding blood for WLI and RDI. In our case, the color difference of RDI was greater than that of WLI (9. 75 vs 6. 61), and RDI showed a better distinguished bleeding point from the surrounding blood.

CONCLUSION

RDI may improve visualization of the bleeding point by providing better contrast in color difference relative to surrounding blood.

Early stage clear cell adenocarcinoma coexisting with tubular adenoma and adenoma with clear cell change in the colon

Primary clear cell adenocarcinoma (CCA) of the colorectum is rare. We report a case of a 57-year-old man with early-stage CCA with conventional tubular adenoma and tubular adenoma with clear cell change in the transverse colon, diagnosed with image-enhanced endoscopy. The tumor was then treated with endoscopic submucosal dissection. The endoscopic findings characteristic of clear cell adenoma/adenocarcinoma could not be identified. Therefore, similar diagnostic tools as for conventional colorectal adenoma/cancer were considered. The pathogenesis of the clear cell change was unknown, but it might appear with the progression of the malignancy.

Diagnosis of early gastric cancer using image enhanced endoscopy: a systematic approach

This paper provides an overview of the principles of a vessel plus surface (VS) classification system to explain the diagnostic system of early gastric cancer using image-enhanced magnifying endoscopy. Furthermore, this paper introduces the magnifying endoscopy simple diagnostic algorithm for gastric cancer (MEADA-G) developed according to the VS classification system, with a description of the procedures performed for diagnosis. In addition to the diagnostic system, white opaque substance (WOS), light blue crest (LBC), white globe appearance (WGA), and vessels within epithelial circle (VEC) patterns, which are representative findings that can be observed in the gastric mucosa by image-enhanced magnifying endoscopy, are also described. Image-enhanced magnifying endoscopy is particularly useful in the diagnosis of differentiated-type early gastric cancer. It is important to use the appropriate clinical strategies based on a comprehensive understanding of the usefulness and limitations of the diagnostic system described in this paper.

A rare case of gastric squamous-cell carcinoma metastasized from the cervix

Gastric squamous-cell carcinoma (SqCC) metastasized form the cervix is rarely detected in endoscopic examination, although cervical carcinoma is the second most common in gynecologic malignancy. A 59-year-old female visited a clinic for anorexia, and an esophago-gastro-duodenoscopy (EGD) revealed multiple submucosal tumors (SMTs) of the stomach. After she was referred, an image-enhanced endoscopy enhanced multiple SMTs with white spots, whose findings were irregular micro-vascular patterns in the mucosa with irregular/absent micro-surface pattern. We took endoscopic biopsies, whose histological diagnoses were SqCC in the layer of the lamina propria under normal epithelium. Positron emission tomography-CT, CT and magnetic resonance imaging revealed an irregularly enhanced mass of the cervix, the irregularly thickening wall of the stomach and peritoneal nodules. Palliative care alone was administered based on poor condition associated with the Stage IV cervical carcinoma. In this case, endoscopic detection of gastric SqCC might provide a tip to make final diagnosis of primary site of cervical SqCC. The numbers of endoscopic examination become increasing, so further deep awareness of such patterns of metastasis in cervical cancer are required.

Benefits of linked color imaging for recognition of early differentiated-type gastric cancer: in comparison with indigo carmine contrast method and blue laser imaging

BACKGROUND AND AIM

Linked color imaging (LCI) is a novel endoscopy system, which enhances slight differences in mucosal color. However, whether LCI is more useful than other kinds of image-enhanced endoscopy (IEE) in recognizing early gastric cancer remains unclear. This study aimed to evaluate LCI efficacy compared with the indigo carmine contrast method (IC), and blue laser imaging-bright (BLI-brt) in early differentiated-type gastric cancer recognition.

METHODS

We retrospectively analyzed early differentiated-type gastric cancer, which were examined by all four imaging techniques (white light imaging, IC, LCI, BLI-brt) at Asahi University Hospital from June 2014 to November 2018. Both subjective evaluation (using ranking score: RS) and objective evaluation (using color difference score: CDS) were adopted to quantify early differentiated-type gastric cancer recognition.

RESULTS

During this period, 87 lesions were enrolled in this study. Both RS and CDS of LCI were significantly higher (p < 0.01) than those of IC and BLI-brt. Both RS and CDS of BLI-brt had no significant difference compared with those of IC. Subgroup analysis revealed that LCI was especially useful in post-Helicobacter pylori eradication patients and flat or depressed lesions compared with IC and BLI-brt.

CONCLUSIONS

LCI appears to be more beneficial for the recognition of early differentiated-type gastric cancer in endoscopic screenings than IC and BLI-brt from the middle to distant view.

Endoscopic Diagnosis and Treatment of Esophageal Squamous Cell Carcinoma

Esophageal squamous cell carcinoma (ESCC) is a deadly disease, partly because it is often diagnosed late in disease stage. An accurate early diagnosis by endoscopy could detect advanced carcinoma as well as curable dysplasia and early ESCC. This could save patients from incurable advanced malignancy. Important progress has been made in high-quality endoscopic diagnosis, including magnifying endoscopy, narrowband imaging, and other image enhancement, as well as in techniques in endoscopic resection. These emerging techniques will aid the early diagnosis of ESCC that lead to higher chance of curing the cancer.

Clinical benefits from endoscopy screening of esophageal second primary tumor for head and neck cancer patients: Analysis of a hospital-based registry

OBJECTIVES

Esophageal second primary tumors (SPTs) in head and neck cancer (HNC) patients is not uncommon. The impact of image-enhanced endoscopy (IEE) screening for esophageal SPT on the outcome of HNC patients has not been well clarified.

METHODS AND METHODS

Patients with malignancies of the head and neck region and esophagus were recruited from a hospital-based cancer registry between July 2000-December 2016. IEE screening included magnifying endoscopy with narrow-band imaging and chromoendoscopy with Lugol's solution. Biopsied specimens with revised Vienna classification categories 1 and 2 were defined as group I, and those with categories 3 to 5 were defined as group II. The Kaplan-Meier estimate and Cox regression model were used for survival analysis.

RESULTS

Totally 1577 HNC and 501 esophageal cancer patients were enrolled. The 5-year overall survival (OS) rates of stage I/II HNC, stage III/IV HNC and esophageal cancer patients were 58%, 29%, and 8%, respectively (p < 0.01). The 5-year OS rate of HNC patients with negative IEE results was higher than that of HNC patients without IEE screening, followed by IEE screening groups I, II and esophageal cancer patients (44% vs. 39% vs. 35% vs. 11% vs. 8%, respectively, p for trend <0.01). Among advanced HNC patients, those who received IEE screening had a trend of better prognosis than those without screening (5-year OS rate of 31% vs. 28%, p = 0.17).

CONCLUSIONS

IEE screening for esophageal SPTs is helpful in risk stratification and prognosis prediction for HNC patients. Routine IEE screening is recommended in HNC patients.

Current status of esophageal endoscopy including the evaluation of smoking and alcohol consumption in Japan: an analysis based on the Japan endoscopy database

PURPOSE

The aim was to investigate the current status of esophageal endoscopy, including the evaluation of smoking and alcohol consumption, in Japan.

METHODS

A total of 47,441 patients who underwent 69,748 sessions of esophageal endoscopy were registered in the Japan Endoscopy Database between January 2015 and March 2017. The study variables were as follows: (1) methods for monitoring the esophagus and the time required for monitoring and (2) the status of smoking and alcohol consumption in patients with esophageal cancer and head and neck cancer.

RESULTS

Image-enhanced endoscopy was performed in 10.6%, Lugol chromoendoscopy in 4.1%, and magnifying endoscopy in 3.2%. The mean time required for gastrointestinal endoscopy was 10 min 58 s. The mean examination times in patients with or without monitoring of the head and neck were 10 min 51 s and 11 min 13 s, respectively. In 57.0% of the patients with esophageal cancer, the head and neck were monitored at the time of gastrointestinal endoscopy. The proportion of current smokers (esophageal cancer: 16.8-4.7%; head and neck cancer: 24.3-9.3%) and addicted drinkers (esophageal cancer: 52.3-40.8%; head and neck cancer: 50.2-47.3%) were lower at the second or subsequent endoscopy than at the initial endoscopy.

CONCLUSIONS

The new strategy for esophageal endoscopy has led to an evolutionary change in Japan. The patients with esophageal cancer and head and neck cancer who underwent a second or subsequent endoscopy had lower incidences of smoking and alcohol consumption, although the incidences remained high.

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

BACKGROUND AND AIMS

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

METHODS

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

RESULTS

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

CONCLUSION

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

Linked color imaging can help gastric Helicobacter pylori infection diagnosis during endoscopy

BACKGROUND

Esophagogastroduodenoscopy (EGD) is a standard tool for detection of mucosal and submucosal lesions. However, identification of Helicobacter pylori (H. P) infection using EGD alone is limited in accuracy. Linked color imaging (LCI) is a novel tool to capture real-time image with sufficient contrast to observe mucosal microstructure.

METHODS

This study aims to evaluate the applicability of LCI in the identification of H. pylori infection. Consecutive 122 patients scheduled for EGD were included. They were examined with LCI and magnifying endoscopy. The classification of H. pylori was based on pathology results of biopsy and rapid urease test or urea breath test.

RESULTS

We compared the results based on LCI or magnifying endoscopy to reference classification. Of 122 patients, 36 had H. pylori infection (29.51%). The level of accuracy of diagnosis of H. pylori infections by LCI, magnifying endoscopy, and both LCI and magnifying endoscopy was 78.38%, 81.98%, and 78.38%, respectively. The sensitivity and specificity of each group were 70.97%, 81.25%, and 80.65% and 82.5%, 83.87%, and 76.25%, respectively. The positive predictive values were 59.46%, 64.10%, and 57.78%, respectively, and the negative predictive values were 87.84%, 91.67%, and 92.42%, respectively.

CONCLUSION

LCI could be playing a valuable initial screen tool for real-time diagnosis of H. pylori infections. It has a high accuracy of diagnosis of H. pylori infections. Therefore, in patients suspected to have H. pylori infections using LCI, the infections need to be carefully diagnosed using appropriate methods because, as per the consensus, they should be eradicated as soon as possible before precancerous lesions develop.

Endoscopic microanatomy of the normal gastrointestinal mucosa with narrow band technology and magnification

The development of high-definition endoscopes with optical zoom, along with the use of the digital chromoendoscopy and staining, has given endoscopists the possibility to study the microanatomy of the gastrointestinal mucosa in vivo. The recognition of the changes in the microstructure of the surface and microvascular architecture such as those that occur in neoplastic lesions allow us to characterize these lesions in order to decide on the best course of clinical action. The current greater availability of endoscopes with optical zoom in western countries has allowed the use of this technology in routine clinical practice to spread. In this article we review the basic concepts of magnifying endoscopy and the normal endoscopic microanatomy of the oesophageal, gastric, duodenal, ileal and colonic mucosa.

Early stage clear cell adenocarcinoma of the colon examined in detail with image-enhanced endoscopy: a case report

Primary clear cell adenocarcinoma (CCA) of the colorectum is a rare tumor. We report on a 48-year-old man with early stage CCA in the descending colon who underwent detailed examination with image-enhanced endoscopy, such as magnifying endoscopy with narrow-band imaging and crystal violet staining. The tumor was treated successfully with endoscopic mucosal resection at our hospital.

Application of image-enhanced endoscopy in diagnosis of colorectal cancer

Colorectal cancer (CRC) is one of the most common malignancies, and in China the incidence and mortality of CRC are among the top in the world. Early diagnosis of CRC can improve the prognosis significantly. Image enhancement techniques have already been applied to endoscopy, including narrow band imaging, flexible spectral imaging, i-Scan, and blue laser imaging endoscopy system. These techniques, combined with image pre-processing or post-processing method, might improve the detection of lesions by enhancing the color contrast between lesions and their surrounding mucosa. Nowadays, several classification systems for colorectal tumors have been established based on the surface pattern and microvascular morphology of lesions. Image enhancement technology might display the microvascular structures more clearly and determine the malignancy and infiltrating depth of lesions more accurately.

Surveillance of patients with inflammatory bowel disease

Patients with inflammatory bowel disease involving the colon are at increased risk for developing colorectal cancer. Colonoscopy surveillance is important to identify and treat IBD associated dysplasia. The SCENIC consensus provides evidence-based recommendations for optimal surveillance and management of dysplasia in IBD. Chromoendoscopy, with the surface application of dyes to enhance mucosal visualization, is the superior endoscopic surveillance strategy to detect dysplasia. Most dysplasia is visible, and can be endoscopically resected. Future studies should determine the effect of new surveillance strategies on the incidence of CRC and mortality in patients with IBD.

Advanced Imaging Technology in Biliary Tract Diseases:Narrow-Band Imaging of the Bile Duct

Newly introduced direct peroral cholangioscopy and the development of video choledochoscopes have enabled more defined observation of bile duct mucosal lesions with clearer images. Narrow-band imaging (NBI) is a unique endoscopic imaging technology that provides enhanced endoscopic images of surface mucosal structures and its superficial microvessels. Advanced cholangioscopy and NBI are expected to be useful for precise evaluation and correct diagnosis of biliary tract diseases. However, the diagnostic value of advanced bile duct imaging with cholangioscopy requires further evaluation.

Advanced Imaging Technology Other than Narrow Band Imaging

To improve the detection rate of gastrointestinal tumors, image-enhanced endoscopy has been widely used during screening and surveillance endoscopy in Korea. In addition to narrow band imaging (NBI) with/without magnification, various types of electronic chromoendoscopies have been used, including autofluorescence imaging, I-scan, and flexible spectral imaging color enhancement. These technologies enable the accurate characterization of tumors because they enable visualization of microvascular and microsurface patterns. The present review focuses on understanding the principle and clinical applications of advanced imaging technologies other than NBI.

The Past, Present, and Future of Image-Enhanced Endoscopy

Despite the remarkable progress recently made to enhance the resolution of white-light endoscopy, detection, and diagnosis of premalignant lesions, such as adenomas and subtle early-stage cancers, remains a great challenge. As for example, although chromoendoscopy, such as endoscopy using indigo carmine, is useful for the early diagnosis of subtle lesions, the technique presents various disadvantages ranging from the time required for spray application of the dye and suctioning of excess dye to the increased difficulty in identifying lesions in the presence of severe inflammation and obstruction of visual field due to the pooling of solution in depressed-type lesions. To overcome these diagnostic problems associated with chromoendoscopy, research has focused on the development of endoscopes based on new optical technologies. Several types of image-enhanced endoscopy methods have recently been presented. In particular, image-enhanced endoscopy has emerged as a new paradigm for the diagnosis of gastrointestinal disorders. Image-enhanced endoscopes provide high-contrast images of lesions by means of optical or electronic technologies, including the contrast enhancement of the mucosal surface and of blood vessels. Chromoendoscopy, narrow-band imaging, i-SCAN, and flexible spectral imaging color enhancement are representative examples of image-enhanced endoscopy discussed in this paper.

Can image-enhanced cholangioscopy distinguish benign from malignant lesions in the biliary duct?

A new video peroral cholangioscopy (POCS) has been developed with high-quality digital imaging, and its clinical use has been reported. Additionally, direct peroral cholangioscopy (D-POCS) using an ultraslim endoscope has been proposed recently. To improve the diagnostic yield of POCS or D-POCS, image-enhanced endoscopy has been used in combination. Chromoendoscopy with methylene blue staining (ME), autofluorescence imaging (AFI), and narrow-band imaging (NBI) has been evaluated in biliary tract diseases. Observation of the mucosal structure and vessels is reportedly important for distinguishing non-neoplasms from neoplasms. Therefore, NBI is the most promising tool among image-enhanced endoscopies as it can enhance visualization of the mucosal structure and vessels simultaneously. There are currently few reports that have evaluated the utility of POCS or D-POCS based on pathological findings. Thus, endoscopic findings of the bile duct mucosa have not yet been fully established. At present, POCS-guided biopsy should be carried out.

Image-enhanced capsule endoscopy for characterization of small bowel lesions

Video capsule endoscopy has revolutionized direct endoscopic imaging of the gut. Small-bowel video capsule endoscopy (SBVCE) is now the first-line procedure for exploring the small bowel in case of obscure digestive bleeding and has also some room in case of Crohn's disease, coeliac disease and polyposis syndrome. In case of obscure digestive bleeding the main lesions are angioectasias, erosions/ulcerations and tumors. As for conventional optical endoscopy search was done for improving the detection and characterization of small-bowel lesions. The Fujinon Intelligent Chromoendoscopy (FICE) has been adapted on the software of the SBVCE (Given Imaging(®)/Medtronics). Although there are some conflicting results on the efficacy of FICE for detecting more lesions than with conventional light, it is now recognized that FICE - particularly the setting 1 - may enhance the delineation or characterization of lesions. The use of three-dimensional representation technique is now feasible but still needs further research.

Detection and characterization of early malignancy in the esophagus: what is the best management algorithm?

Barrett's esophagus is a known precursor for esophageal adenocarcinoma. Early detection of dysplasia provides a window of opportunity for curative intervention. Several image-enhanced technologies have been developed to improve visualization of neoplasia. These however have not been found to be superior to the standard four quadrant random biopsy protocol. Patients are risk-stratified based on the degree of dysplasia found on biopsies and undergo either surveillance or treatment. Endoscopic therapy has become the mainstay of treatment for early neoplasia.

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

AIM: To assess the risk of failing to detect diminutive and small colorectal cancers with the “resect and discard” policy.

METHODS: Patients who received colonoscopy and polypectomy were recruited in the retrospective study. Probable histology of the polyps was predicted by six colonoscopists by the use of NICE classification. The incidence of diminutive and small colorectal cancers and their endoscopic features were assessed.

RESULTS: In total, we found 681 cases of diminutive (1-5 mm) lesions in 402 patients and 197 cases of small (6-9 mm) lesions in 151 patients. Based on pathology of the diminutive and small polyps, 105 and 18 were non-neoplastic polyps, 557 and 154 were low-grade adenomas, 18 and 24 were high-grade adenomas or intramucosal/submucosal (SM) scanty invasive carcinomas, 1 and 1 were SM-d carcinoma, respectively. The endoscopic features of invasive cancer were classified as NICE type 3 endoscopically.

CONCLUSION: The risk of failing to detect diminutive and small colorectal invasive cancer with the “resect and discard” strategy might be avoided through the use of narrow-band imaging observation with the NICE classification scheme and magnifying endoscopy.

Detection of nonpolypoid colorectal neoplasia using magnifying endoscopy in colonic inflammatory bowel disease

Patients with inflammatory bowel diseases (IBD) have a high risk of colitis-associated dysplasia and cancer. It is important that careful surveillance with colonoscopy is performed for all patients with IBD and, more frequently, for those considered to be at high risk. Traditionally, flat dysplasia in ulcerative colitis has been considered to be detectable only by using random biopsy specimens of mucosa that appeared unremarkable during endoscopy. However, recent studies have shown that most of them are visible; thus, their detection as nonpolypoid colorectal neoplasms is an integral component in the prevention of colitic cancer.

Image-enhanced endoscopy for diagnosis of colorectal tumors in view of endoscopic treatment

Recently, image-enhanced endoscopy (IEE) has been used to diagnose gastrointestinal tumors. This method is a change from conventional white-light (WL) endoscopy without dyeing solution, requiring only the push of a button. In IEE, there are many advantages in diagnosis of neoplastic tumors, evaluation of invasion depth for cancerous lesions, and detection of neoplastic lesions. In narrow band imaging (NBI) systems (Olympus Medical Co., Tokyo, Japan), optical filters that allow narrow-band light to pass at wavelengths of 415 and 540 nm are used. Mucosal surface blood vessels are seen most clearly at 415 nm, which is the wavelength that corresponds to the hemoglobin absorption band, while vessels in the deep layer of the mucosa can be detected at 540 nm. Thus, NBI also can detect pit-like structures named surface pattern. The flexible spectral imaging color enhancement (FICE) system (Fujifilm Medical Co., Tokyo, Japan) is also an IEE but different to NBI. FICE depends on the use of spectral-estimation technology to reconstruct images at different wavelengths based on WL images. FICE can enhance vascular and surface patterns. The autofluorescence imaging (AFI) video endoscope system (Olympus Medical Co., Tokyo, Japan) is a new illumination method that uses the difference in intensity of autofluorescence between the normal area and neoplastic lesions. AFI light comprises a blue light for emitting and a green light for hemoglobin absorption. The aim of this review is to highlight the efficacy of IEE for diagnosis of colorectal tumors for endoscopic treatment.