Fuji Intelligent Chromo Endoscopy and staining technique for the diagnosis of colon tumor:

Optical Technologies for Endoscopic Real-Time Histologic Assessment of Colorectal Polyps: A Meta-Analysis

OBJECTIVES

Accurate, real-time, endoscopic risk stratification of colorectal polyps would improve decision-making and optimize clinical efficiency. Technologies to manipulate endoscopic optical outputs can be used to predict polyp histology in vivo; however, it remains unclear how accuracy has progressed and whether it is sufficient for routine clinical implementation.

METHODS

A meta-analysis was conducted by searching MEDLINE, Embase, and the Cochrane Library. Studies were included if they prospectively deployed an endoscopic optical technology for real-time in vivo prediction of adenomatous colorectal polyps. Polyposis and inflammatory bowel diseases were excluded. Bayesian bivariate meta-analysis was performed, presenting 95% confidence intervals (CI).

RESULTS

One hundred two studies using optical technologies on 33,123 colorectal polyps were included. Digital chromoendoscopy differentiated neoplasia (adenoma and adenocarcinoma) from benign polyps with sensitivity of 92.2% (90.6%-93.9% CI) and specificity of 84.0% (81.5%-86.3% CI), with no difference between constituent technologies (narrow-band imaging, Fuji intelligent Chromo Endoscopy, iSCAN) or with only diminutive polyps. Dye chromoendoscopy had sensitivity of 92.7% (90.1%-94.9% CI) and specificity of 86.6% (82.9%-89.9% CI), similarly unchanged for diminutive polyps. Spectral analysis of autofluorescence had sensitivity of 94.4% (84.0%-99.1% CI) and specificity of 50.9% (13.2%-88.8% CI). Endomicroscopy had sensitivity of 93.6% (85.3%-98.3% CI) and specificity of 92.5% (81.8%-98.1% CI). Computer-aided diagnosis had sensitivity of 88.9% (74.2%-96.7% CI) and specificity of 80.4% (52.6%-95.7% CI). Prediction confidence and endoscopist experience alone did not significantly improve any technology. The only subgroup to demonstrate a negative predictive value for adenoma above 90% was digital chromoendoscopy, making high confidence predictions of diminutive recto-sigmoid polyps. Chronologic meta-analyses show a falling negative predictive value over time. A significant publication bias exists.

DISCUSSION

This novel approach to meta-analysis demonstrates that existing optical technologies are increasingly unlikely to allow safe "resect and discard" strategies and that step-change innovation may be required. A "diagnose and leave" strategy may be supported for diminutive recto-sigmoid polyps diagnosed with high confidence; however, limitations exist in the evidence base for this cohort.

Accuracy of i-Scan for Optical Diagnosis of Colonic Polyps: A Meta-Analysis

Background

i-Scan is a novel virtual chromoendoscopy system designed to enhance surface and vascular patterns to improve optical diagnostic performance. Numerous prospective studies have been done to evaluate the accuracy of i-Scan in differentiating colonic neoplasms from non-neoplasms. i-Scan could be an effective endoscopic technique for optical diagnosis of colonic polyps.

Objective

Our aim of this study was to perform a meta-analysis of published data to establish the diagnostic accuracy of i-Scan for optical diagnosis of colonic polyps.

Methods

We searched PubMed, Medline, Elsevier ScienceDirect and Cochrane Library databases. We used a bivariate meta-analysis following a random effects model to summarize the data and plotted hierarchical summary receiver-operating characteristic (HSROC) curves. The area under the HSROC curve (AUC) serves as an indicator of the diagnostic accuracy.

Results

The meta-analysis included a total of 925 patients and 2312 polyps. For the overall studies, the area under the HSROC curve was 0.96. The summary sensitivity was 90.4% (95%CI 85%-94.1%) and specificity was 90.9% (95%CI 84.3%-94.9%). In 11 studies predicting polyps histology in real-time, the summary sensitivity and specificity was 91.5% (95%CI 85.7%-95.1%) and 92.1% (95%CI 84.5%-96.1%), respectively, with the AUC of 0.97. For three different diagnostic criteria (Kudo, NICE, others), the sensitivity was 86.3%, 93.0%, 85.0%, respectively and specificity was 84.8%, 94.4%, 91.8%, respectively.

Conclusions

Endoscopic diagnosis with i-Scan has accurate optical diagnostic performance to differentiate neoplastic from non-neoplastic polyps with an area under the HSROC curve exceeding 0.90. Both the sensitivity and specificity for diagnosing colonic polyps are over 90%.

Diagnostic performance of narrowed spectrum endoscopy, autofluorescence imaging, and confocal laser endomicroscopy for optical diagnosis of colonic polyps: a meta-analysis

BACKGROUND

Novel endoscopic technologies could allow optical diagnosis and resection of colonic polyps without histopathological testing. Our aim was to establish the sensitivity, specificity, and real-time negative predictive value of three types of narrowed spectrum endoscopy (narrow-band imaging [NBI], image-enhanced endoscopy [i-scan], and Fujinon intelligent chromoendoscopy [FICE]), confocal laser endomicroscopy (CLE), and autofluorescence imaging for differentiation between neoplastic and non-neoplastic colonic lesions.

METHODS

We identified relevant studies through a search of Medline, Embase, PubMed, and the Cochrane Library. Clinical trials and observational studies were eligible for inclusion when the diagnostic performance of NBI, i-scan, FICE, autofluorescence imaging, or CLE had been assessed for differentiation, with histopathology as the reference standard, and for which a 2 × 2 contingency table of lesion diagnosis could be constructed. We did a random-effects bivariate meta-analysis using a non-linear mixed model approach to calculate summary estimates of sensitivity and specificity, and plotted estimates in a summary receiver-operating characteristic curve.

FINDINGS

We included 91 studies in our analysis: 56 were of NBI, ten of i-scan, 14 of FICE, 11 of CLE, and 11 of autofluorescence imaging (more than one of the investigated modalities assessed in eight studies). For NBI, overall sensitivity was 91·0% (95% CI 88·6-93·0), specificity 85·6% (81·3-89·0), and real-time negative predictive value 82·5% (75·4-87·9). For i-scan, overall sensitivity was 89·3% (83·3-93·3), specificity 88·2% (80·3-93·2), and real-time negative predictive value 86·5% (78·0-92·1). For FICE, overall sensitivity was 91·8% (87·1-94·9), specificity 83·5% (77·2-88·3), and real-time negative predictive value 83·7% (77·5-88·4). For autofluorescence imaging, overall sensitivity was 86·7% (79·5-91·6), specificity 65·9% (50·9-78·2), and real-time negative predictive value 81·5% (54·0-94·3). For CLE, overall sensitivity was 93·3% (88·4-96·2), specificity 89·9% (81·8-94·6), and real-time negative predictive value 94·8% (86·6-98·1).

INTERPRETATION

All endoscopic imaging techniques other than autofluorescence imaging could be used by appropriately trained endoscopists to make a reliable optical diagnosis for colonic lesions in daily practice. Further research should be focused on whether training could help to improve negative predictive values.

FUNDING

None.

Computer-generated surface and tone enhancements to distinguish neoplastic from non-neoplastic colon polyps less than 1 cm in diameter

BACKGROUND AND STUDY AIMS

Computer-generated enhancements, which can highlight the surface and color of a colonic lesion, may be helpful to predict the histology; however, it remains unclear whether this technology can distinguish neoplastic from non-neoplastic colon polyps when the polyps are <1 cm without magnification.

PATIENTS AND METHODS

Images of colorectal polyps less than 1 cm in diameter were obtained from 54 patients who underwent non-magnified colonoscopy with surface enhancement (SE) and tone enhancement (TE). We calculated the sensitivity, specificity, and accuracy in the prediction of histology. Inter- and intra-observer consistency was evaluated by inviting four endoscopists to rate 45 static images.

RESULTS

Overall sensitivity, specificity, and accuracy following the sequence of SE, TE colon, and TE pit pattern modes were 87.7% (95% confidence interval 81.3-94.1%), 84.1% (76.9-91.3%), and 86.1% (79.4-92.8%), respectively. For each modality, the results were 75.0% (68.7-81.3%), 82.7% (77.2-88.2%), and 77.2% (71.1-83.3%) for SE; 71.1% (64.5-77.7%), 78.8 (72.8-84.8), and 73.3% (66.8-79.8%) for TE colon mode; and 75.0% (68.7-81.3%), 80.8% (75.0-86.8%), and 76.7% (70.5-82.9%) for TE pit pattern mode. Their inter- and intra-observer agreements were all fair (κ range 0.522-0.568) and good (0.605-0.694), respectively. When the same rater evaluated the same lesion under different modalities, eight of 45 (18%) polyps yielded discordant interpretations, and the possibility of incorrect diagnoses was the highest with the TE colon mode.

CONCLUSION

Computer-generated enhancements are satisfactory in predicting the histology of small colon polyps without the need for magnification. This advantage is mostly related to the pit pattern enhancement.

Diagnostic performance of chromoendoscopy and narrow band imaging for colonic neoplasms: a meta-analysis

AIM

We conducted a meta-analysis to compare the diagnostic test performance of chromoendoscopy and narrow band imaging (NBI) for colonic neoplasms.

METHOD

MEDLINE, EMBASE and the Cochrane Library were searched (1966 to March 2009). Articles were included if: (i) chromoendoscopy or NBI was used, (ii) sensitivity and specificity were reported; (iii) absolute numbers of true-positive, false-positive, true-negative and false-negative results were provided or could be calculated; and (iv) pathology was used as the reference standard. Sensitivity and specificity were pooled using random effects model. Secondary analyses were conducted by limiting the studies in which magnifying endoscopy was used alone as a diagnostic modality, and polyp size and macroscopic appearance of lesions were not considered.

RESULTS

Of 1342 screened articles, 27 met the inclusion criteria. Pooled sensitivity for chromoendoscopy and NBI was 0.94 (95% CI, 0.92-0.95) and 0.94 (0.91-0.97), and specificity was 0.82 (0.77-0.88) and 0.86 (0.83-0.89), respectively. There were no differences in sensitivity (P = 0.99) or specificity (P = 0.54) between the two methods. In the secondary analysis, pooled sensitivity for choromoendoscopy and NBI was 0.93 (95% CI, 0.90-0.97) and 0.96 (0.93-0.99) and specificity was 0.80 (0.73-0.87) and 0.85 (0.78-0.92). respectively. Overall, the pooled false-negative rate was 0.057 (95% CI, 0.040-0.73) for chromoendoscopy and 0.057 (95% CI, 0.028-0.085) for NBI.

CONCLUSION

Chromoendoscopy and NBI had similar diagnostic test characteristics in the assessment of colonic neoplasms; however, the false-negative rate for both methods of 5.7% is an unacceptably high rate and currently therefore, neither method is ready for general use.

Clinical usefulness of pit patterns for detecting colonic lesions requiring surgical treatment

BACKGROUND

The number of patients suffering from colorectal cancer is increasing. According to Japanese guidelines, lesions with a submucosal invasive depth >1,000 μm should be treated with radical proctocolectomy. We propose and evaluate a new clinical classification for pit patterns that uses endoscopy to assess lesion depth for determination of the appropriate therapeutic approach for early colorectal cancers and adenomas.

METHODS

Endoscopic images of colorectal adenomas and early cancer cases with type V(I) pit pattern, resected surgically or endoscopically from April 2002 to April 2007 at Showa University Yokohama Northern Hospital, were utilized for analysis. Each image was retrospectively analyzed for (A) pit narrowness, (B) irregular pit margins, and (C) indistinct stromal staining. Sensitivity, specificity, and predictive value were evaluated as major outcomes, using pathological results as the standard.

RESULT

In total, 186 cases were assessed. With all features considered (A, B, and C), the sensitivity, specificity, and positive and negative predictive values were 47.8%, 86.3%, 66.0%, and 74.2%, respectively. When limited to two features (A and B), these values were 75.3%, 81.2%, 70.2%, and 84.8%, respectively.

CONCLUSION

Our results suggest that the established criteria can, to a certain degree, distinguish between high and low irregularity in colorectal lesions with V(I) pit pattern indicating submucosal cancer infiltration of more or less than 1,000 μm with the clinical consequence of surgery versus endoscopic mucosal resection/endoscopic mucosal dissection.

The endoscopic diagnosis of nonerosive reflux disease using flexible spectral imaging color enhancement image: a feasibility trial

Nonerosive reflux disease (NERD) is classified into grade M (minimal change, endoscopically; erythema without sharp demarcation, whitish turbidity, and/or invisibility of vessels due to these findings) and grade N (normal) in the modified Los Angeles classification system in Japan. However, the classification of grades M and N NERD is not included in the original Los Angeles system because interobserver agreement for the conventional endoscopic diagnosis of grades M or N NERD is poor. Flexible spectral imaging color enhancement (FICE) is a virtual chromoendoscopy technique that enhances mucosal and vascular visibility. The aim of this study is to evaluate whether the endoscopic diagnosis of grades M or N NERD using FICE images is feasible. Between April 2006 and May 2008, 26 NERD patients and 31 controls were enrolled in the present study. First, an experienced endoscopist assessed the color pattern of minimal change in FICE images using conventional endoscopic images and FICE images side-by-side and comparing the proportion of minimal change between the two groups. Second, three blinded endoscopists assessed the presence or absence of minimal change in both groups using conventional endoscopic images and FICE images separately. Intraobserver variability was compared using McNemar's test, and interobserver agreement was described using the kappa value. Minimal changes, such as erythema and whitish turbidity, which were detected using conventional endoscopic images, showed up as navy blue and pink-white, respectively, in color using FICE images in the present FICE mode. The NERD group had a higher proportion of minimal change, compared with the control group (77% and 48%, respectively) (P= 0.033). In all three readers, the detection rates of minimal change using FICE images were greater than those using conventional endoscopic images (P= 0.025, <0.0001, and 0.034 for readers A, B, and C, respectively). The kappa values for all pairs of three readers using FICE images were between 0.683 and 0.812, while those using conventional endoscopic images were between 0.364 and 0.624. Thus, the endoscopic diagnosis of grades M or N NERD using FICE images is feasible and may improve interobserver agreement.

Advances in endoscopic visualization of colorectal polyps

AIM

Conventional white-light endoscopy is currently the gold standard for the detection and treatment of colorectal polyps. However, up to a fifth of polyps may be missed on initial examination, especially flat and small mucosal lesions. This study reviews the literature reporting on the use of new advances in endoscopic visualization.

METHOD

Literature searches were performed on PubMed using the terms 'chromoendoscopy', 'narrow-band imaging' (NBI), 'autofluorescence imaging' (AFI), 'Fujinon Intelligent Colour Enhancement' (FICE), 'i-Scan colonoscopy', 'zoom colonoscopy' and 'confocal laser endomicroscopy' (CLE). We focused on systematic reviews, national guidelines and randomized controlled trials written in English. Studies were assessed for methodological quality using QUADAS. Prospective studies assessing new technology were also reviewed. Further publications were identified from reference lists.

RESULTS

Chromoendoscopy increases the detection of neoplastic polyps compared with conventional colonoscopy. NBI avoids the use of additional dyes and enhances the vascular network of capillaries surrounding the crypts, increasing the adenoma detection rate and the ability to distinguish between neoplastic and non-neoplastic lesions. FICE, AFI and i-Scan are new developments that improve tissue contrast. Zoom endoscopy may be combined with different modalities to help further characterize colonic lesions. CLE provides live in vivo high-resolution optical sections of tissue and may be particularly useful in the surveillance of patients with long-standing ulcerative colitis, reducing the number of random biopsies.

CONCLUSION

Although there is mounting evidence that these new technologies are superior to conventional endoscopy, current guidelines are limited. Further large-scale randomized controlled trials comparing these modalities in different patient subpopulations are warranted.

Spectral endoscopic imaging: the multiband system for enhancing the endoscopic surface visualization

In the past few years, newly developed procedures and technologies have improved endoscopic recognition of the gastrointestinal tract. In particular, narrow band imaging, multiband imaging, and contrast enhancement make possible the "real-time," on demand recognition of the gastrointestinal mucosa during the endoscopic examination. These imaging techniques have been designed to enhance visualization of the vascular network and surface texture of the mucosa in an effort to improve tissue characterization, differentiation, and diagnosis. These techniques are considered as potential alternatives to chromoendoscopy because they provide contrast enhancement of tissue surface structures. This review focuses on data published on multiband imaging system. We report the technological basis of the system and speculate on its applications. Therefore, PubMed was searched for articles published up to 31 October 2009 using, in combination, these terms: "multiband imaging," "band imaging," "endoscopy," "high-resolution," "gastrointestinal," "FICE," "magnification," "spectral endoscopic images," "computed virtual chromoendoscopy." The reference list of articles identified in the initial PubMed search was reviewed for further relevant publications. Abstracts of communications presented to the most relevant international meetings and congresses were also included in this review. We did not carry out meta-analyses and reviewed only articles published in English.

Computerized virtual chromoendoscopy versus indigo carmine chromoendoscopy combined with magnification for diagnosis of small colorectal lesions: a randomized and prospective study

BACKGROUND AND STUDY AIMS

Magnifying colonoscopy with indigo carmine dye and the analysis of the capillary and the pit patterns by computed virtual chromoendoscopy (Fujinon Intelligent Color Enhancement, FICE) with magnification are effective for the differential diagnosis of neoplastic and non-neoplastic lesions. This study aimed to compare the accuracy of virtual and real chromoendoscopy in differentiating neoplastic and non-neoplastic colorectal lesions.

PATIENTS AND METHODS

A prospective randomized trial of magnification colonoscopy with targeted FICE (Group I - 72 patients/111 lesions) versus magnification colonoscopy with targeted indigo carmine dye (Group II - 72 patients/137 lesions) was performed in consecutive patients with lesions 1 cm or less. Histopathology of the specimens was regarded as the gold standard.

RESULTS

In group I, 86 (77.5%) lesions showed an intense vascular pattern (positive capillary meshwork), of which 80 (93%) were histologically confirmed as adenomas. From 25 lesions with negative capillary meshwork, 23 (92%) were non-neoplastic. Sensitivity, specificity, accuracy, positive and negative predictive values of the capillary meshwork for the differential diagnosis of these lesions was 97.8, 79.3, 92.8, 93 and 92%, respectively. The same parameters for pit pattern analysis by FICE were 92.7, 82.3, 90.1, 93.8 and 80%, respectively. Indigo carmine magnified chromoscopy showed sensitivity, specificity, accuracy, positive and negative predictive values of 97, 88.9, 94.9, 96.1 and 91.4%, respectively in the discrimination between neoplastic and non-neoplastic lesions.

CONCLUSION

Magnified virtual chromoendoscopy is as accurate as indigo carmine magnified chromoendoscopy in distinguishing between neoplastic from non-neoplastic small colorectal lesions.

Characterization of follicular lymphoma in the small intestine using double-balloon endoscopy

Follicular lymphomas occur rarely in the gastrointestinal tract, representing only 1-3% of all gastrointestinal tract B-cell non-Hodgkin lymphomas. We describe endoscopic analysis of 3 cases of follicular lymphoma in the small intestine using double-balloon endoscopy. Double-balloon endoscopy revealed multiple nodular lesions and elevated white patches, multiple polypoid lesions, and scattered white polypoid and nodular lesions in the duodenum and small intestine. Fuji Intelligent Chromo Endoscopy demonstrated small, whitish nodules, and narrow-band imaging showed a coiled, elongated vascular pattern within the elevated lesions. These cases are the first follicular lymphomas in the small intestine evaluated using narrow-band imaging or Fuji Intelligent Chromo Endoscopy to be reported.