Narrow-band imaging in the diagnosis of colorectal mucosal lesions: a pilot study

The benefit of using narrow-band imaging systems for observation of capillary networks before determining of treatments for early colon cancer

INTRODUCTION

This study examined whether magnifying endoscopy with narrow-band Imaging observation could be useful selecting the appropriate treatment for early colon cancer.

PATIENTS AND METHODS

We analyzed 551 cases of colon tumors excised endoscopically or surgically, comprising 68 with large hyperplastic polyps, 25 traditional serrated adenomas, 141 tubular adenomas, 177 intramucosal cancers and 140 submucosal invasive (SM) cancers. We classified capillary network pattern into four types according to the degree of dilatation, irregularity and distribution of microcapillary features. These results were then compared with the histological findings.

RESULTS

The comparison of capillary pattern and histological features showed microcapillary networks by magnifying endoscopy with narrow-band imaging observation in intramucosal lesion or SM cancer with remnant neoplastic glands at the superficial layer.

CONCLUSIONS

The remaining microcapillary network was designed to maintain the architecture of neoplastic glands, even in the presence of subumucosal invasion. Consequently, loss of this network could correlate with depth of tumor invasion and histological reaction. Therefore, even if the tumor, remained of network was diagnosed to invade into SM layer, it should be checked up further examination by using magnifying endoscopy with crystal violet staining.

Sano's capillary pattern classification for narrow-band imaging of early colorectal lesions

Narrow-band imaging enhances visualization of the mucosal surface structure and vascular network and helps to increase the visibility of neoplasia by improving contrast. Sano and his colleagues first reported its efficacy for endoscopic use in the gastrointestinal tract and later proposed a sequential classification of the mucosal vascular network patterns according to histopathological categories. Sano's 'capillary pattern classification' was established to facilitate diagnosis of early colorectal lesions on a step-by-step basis. This review focuses on the utility and effectiveness of Sano's capillary pattern classification when examining early colorectal lesions using narrow-band imaging.

Clinical usefulness of narrow band imaging magnifying classification for colorectal tumors based on both surface pattern and microvessel features

We use the narrow band imaging (NBI) magnifying classification (Hiroshima Classification) on the basis of both their surface pattern and microvascular architecture to characterize colorectal tumors. Herein, we describe the Hiroshima Classification in detail and provide statistical data supporting its usefulness in diagnosing histologic type, whether a hyperplastic lesion, tubular adenoma, carcinoma with intramucosal to submucosal scanty invasion or carcinoma with submucosal massive invasion, and thus in selecting the appropriate treatment strategy. We also discuss the circumstances in which the Hiroshima Classification must be augmented by conventional pit pattern diagnosis. NBI magnification is easily carried out. We strongly recommend application of NBI magnification to the differential diagnosis of colorectal lesions as well as treatment decision making.

Endoscopic findings under narrow band imaging colonoscopy in ulcerative colitis

Narrow band imaging (NBI) depicts distinct intramucosal vascular network and pit pattern without any use of dye technique. It is thus suggested that NBI can be used for the assessment of severity in inflammatory bowel diseases, especially in ulcerative colitis (UC). In the active UC, NBI colonoscopy depicts friability as a black area. In the inflamed granular mucosa, crypt openings and villous structure become evident through the procedure. In the inactive UC, there are two types of mucosal vascular pattern; one being composed of deep, green vessels and superficial, black vessels, and the other lacking in superficial vessels. With used of a magnifying instrument, the mildly active mucosa can be classified into the mucosa with obvious crypt openings and that with villous structure. Mucosal vascular pattern in the inactive mucosa is shown as a honeycomb-like structure or irregular, tortuous structure under magnifying NBI observation. Furthermore, such NBI findings show close correlations with histologic findings including crypt distortion, goblet cell depletion and basal plasmacytosis. Therefore, NBI colonoscopy might be of value for the precise assessment of histologic severity in mildly active and inactive UC.

West meets East: preliminary results of narrow band imaging with optical magnification in the diagnosis of colorectal lesions: a multicenter Australian study using the modified Sano's classification

INTRODUCTION

Narrow band imaging with optical magnification (NBI-Z) enables mucosal morphology to be assessed in real time by using light with narrowed band width and magnification of up to 115×.

METHODS

Colorectal lesions detected were assessed with NBI-Z. Histology was predicted using the modified Sano's classification based on capillary network patterns (cn); type I: absent cn (hyperplastic polyp), type II: cn present, surrounding mucosal glands (adenoma), type IIIa: high density cn with tortuosity and lack of uniformity (intramucosal cancer) and type IIIb: nearly avascular cn (invasive cancer). Each lesion was also graded with a confidence level (low/high). High-definition videos (mean 28.2 s; range 12-55) of each lesion assessed with NBI-Z were then taken. This was followed by polypectomy, endoscopic or surgical resection. NBI-Z diagnosis was compared with the final histopathology. To test for interobserver agreement, an endoscopist blinded to the video acquisition process/histology was invited to grade the videos.

RESULTS

A total of 50 lesions (2 assessors: 100 studies), with an average size of 8.4 mm (range 3-30), in 32 patients were assessed. Twenty were hyperplastic, 25 adenomas, 2 intramucosal and 3 invasive cancers of which 19 were located in the right and 31 in the left colon. The overall accuracy of NBI-Z in predicting histology was 90%, which increased to 95% (88/93) when lesions were predicted with high confidence. The sensitivity (Sn), specificity (Sp), positive (PPV) and negative predictive values (NPV) in differentiating neoplastic from non-neoplastic lesions with high confidence were 98%, 89%, 93% and 97%, respectively, while the Sn, Sp, PPV and NPV in predicting endoscopic resectability (type II, IIIa vs type I, IIIb) was 100%, 90%, 93% and 100%, respectively. The interobserver agreement between both assessors (κ value) was substantial at 0.89.

CONCLUSIONS

Using confidence levels, NBI-Z permits prediction of colorectal neoplasia with high accuracies and might allow prompt decisions to be made if a lesion should be left in situ, resected and discarded or biopsied. This approach might lead to substantial time and cost savings and could potentially reduce complications associated with polypectomy and endoscopic resections.

The clinical efficacy and future perspective of narrow band imaging for the diagnosis of colorectal neoplasm

Growing body of evidences have shown that narrow band imaging (NBI) can be the adjunct tool of colonoscopy for real time or optical histological assessment with high accuracy and largely replaces the role of chromoendoscopy. In spite of the advantages, there are still several issues that remain to be elucidated: detectability of neoplastic lesions, diagnosis of malignant transformation, evaluation of invasion depth for cancerous lesion, morphological diagnosis and interobserver agreement. Endoscopists should be aware of the advantage, current evidence and the limitation of narrow band imaging and apply it appropriately for their clinical practice.

Aim to unify the narrow band imaging (NBI) magnifying classification for colorectal tumors: current status in Japan from a summary of the consensus symposium in the 79th Annual Meeting of the Japan Gastroenterological Endoscopy Society

At present, there are many narrow band imaging (NBI) magnifying observation classifications for colorectal tumor in Japan. To internationally standardize the NBI observation criteria, a simple classification system is required. When a colorectal tumor is closely observed using the recent high-resolution videocolonoscope, a pit-like pattern on the tumor can be observed to a certain degree without magnification. In the symposium we could have a consensus that we will name the pit-like pattern as 'surface pattern.' Using the NBI system, the microvessels on the tumor surface can also be recognized to a certain degree. When the NBI system is used, the structure is emphasized, and consequently, the surface pattern can be recognized easily. Recently, an international cooperative group was formed and consists of members from Japan, the USA and Europe, which is named as the Colon Tumor NBI Interest Group. This group has developed a simple category classification (NBI international colorectal endoscopic [NICE] classification), which classifies colorectal tumors into types 1-3 even by closely observing colorectal tumors using a high-resolution videocolonoscope (Validation study is now ongoing by Colon Tumor NBI Interest Group.). The key advantage of this is simplification of the NBI classification. Although the magnifying observation is the best for getting detailed NBI findings, both close observation and magnifying observation using the NICE classification might give almost similar results. Of course the NICE classification can be used more precisely with magnification. In this report we also refer the issues on NBI magnification, which should be solved as early as possible.

Comparison of magnifying chromoendoscopy and narrow-band imaging in estimation of early colorectal cancer invasion depth: a pilot study

BACKGROUND

Several previous studies have identified narrow-band imaging (NBI) with magnification as being useful in evaluating early colorectal cancer invasion depth, but comparative diagnostic accuracy of invasion depth between pit pattern analysis using magnifying chromoendoscopy and NBI remains unclear. The aim of this retrospective study was to compare NBI and pit pattern analysis using magnifying chromoendoscopy in estimating early colorectal cancer invasion depth and to assess interobserver agreement.

PATIENTS AND METHODS

We analyzed a total of 72 early colorectal cancers in 72 patients fulfilling the inclusion criteria. Each lesion image was subsequently reviewed by two experienced colonoscopists (A, B) and then classified clinically based on invasive/non-invasive pattern and Sano's capillary pattern classification with a five-point scale of confidence.

RESULTS

In terms of diagnostic accuracy with confidence for A and B, the areas under the receiver operating characteristics curve were 0.84 and 0.81 for pit pattern analysis and 0.82 and 0.79 for NBI, respectively. Interobserver agreement for the diagnosis of submucosal deep (>1000 µm) invasion was evaluated for both modalities and indicated substantial agreement with pit pattern analysis (κ = 0.63) and moderate agreement with NBI (κ = 0.44).

CONCLUSION

  Estimating invasion depth of early colorectal cancer using NBI appeared to have been comparable to pit pattern analysis, but there was greater interobserver variability using NBI.

Use of narrow band imaging in evaluation of possible nasopharyngeal carcinoma

Background

This study was designed to evaluate the narrow band imaging (NBI) system for its ability to differentiate between malignant neoplasm and benign neoplasm by real-time image during nasopharyngoscopy, the quality of the visualization, and the limitation of the NBI in nasopharyngeal lesions.

Methods

Between June 2009 and May 2010, 63 patients who had a suspected nasopharyngeal tumor via nasopharyngoscopy at Taipei Veterans General Hospital, Taiwan, were included in this study. All of the patients received nasopharyngoscopy with conventional view and NBI view and nasopharyngeal biopsy. The patients were divided into two groups depending on the pathological results: nasopharyngeal carcinoma (NPC) and lymphoid hyperplasia/chronic inflammation (LH).

Results

Forty-one patients were in the NPC group and 22 patients were in the LH group. The pattern of the NBI view showed regular cobblestone in the LH group, except for one patient. The pattern of the NBI view showed an irregular engorged vascular pattern and/or microvascular proliferative pattern in 32 of 41 NPC patients (78.0%). The sensitivity, specificity, positive predictive value, and negative predictive value of NBI in nasopharynx (NP) were 78.0, 95.5, 97.0, and 70.0%, respectively, in NP neoplasm.

Conclusion

NBI could be helpful in differentiating benign and malignant neoplasm in the NP region. Using NBI in NP regions had some limitations, including bleeding and mucus coating.

A novel colonoscope with high color-rendering white light-emitting diodes

BACKGROUND

Light-emitting diodes (LEDs) are being used for a variety of new uses because of their cost-effectiveness and durability. We therefore considered using white LEDs as a light source for GI endoscopes to simplify the endoscopic system.

OBJECTIVE

To assess the feasibility and safety of an LED-illuminated colonoscope.

DESIGN

Pilot study of the LED colonoscope in healthy human volunteers and patients with colorectal lesions.

SETTING

Yamaguchi University Hospital, Ube, Japan.

INTERVENTIONS

We performed a total colonoscopy for 2 healthy volunteers and a sigmoidoscopy for 15 patients with colorectal lesions by using both LED and conventional colonoscopes. We assessed the feasibility and safety of the LED colonoscope by using a 5-grade scale. The 30 images of 15 colorectal lesions obtained by using each endoscope were evaluated in a blind, randomized order by 2 endoscopists.

MAIN OUTCOME MEASUREMENTS

The mean scores of the LED colonoscope for the operability, ease of manipulation, image quality, and safety.

RESULTS

We manufactured a prototype LED colonoscope with white LEDs on its tip. The LED colonoscope did not require an external light source or light-guide fiber bundle. The operability and ease of manipulation of the LED colonoscope were evaluated as similar to those of the conventional colonoscope. The color of the colonic mucosa and the vascular pattern were clearly visualized in the volunteers. For the 15 colorectal lesions, the mean score for image quality was not significantly different between the colonoscopes. The study was performed safely without any incident.

LIMITATIONS

Single-center, small number of patients.

CONCLUSIONS

The use of an LED colonoscope is feasible, and LED illumination may simplify the endoscope system.

Imaging by Magnifying Endoscopy with NBI Implicates the Remnant Capillary Network As an Indication for Endoscopic Resection in Early Colon Cancer

Introduction. This study examined whether magnifying endoscopy with NBI observation (ME-NBI) could be useful selecting the appropriate treatment for submucosal invasive cancer (SM cancer). Patients and Methods. We analyzed 515 cases of colon tumors excised endoscopically or surgically. We classified capillary network pattern into four types according to the degree of dilatation, irregularity, and distribution of microcapillary features. Results. The comparison of capillary pattern and histological features revealed microcapillary networks by using confocal laser-scanning microscopy and ME-NBI in intramucosal lesion or SM cancer with remnant neoplastic glands at the superficial layer. In contrast, the network was absent in SM cancer with desmoplastic reactions, which invaded deeper into the submucosal layer. Conclusions. The remaining microcapillary network is designed to maintain the architecture of neoplastic glands. Consequently, loss of this network could correlate with depth of tumor invasion and desmoplastic reaction. Therefore, we can decide the appropriate treatment by using ME-NBI method.

Narrow-band imaging endoscopy with and without magnification in diagnosis of colorectal neoplasia

AIM: To evaluate the diagnostic efficacies of narrow-band imaging (NBI) endoscopy with and without high magnification in distinguishing neoplasia from non-neoplasia colorectal lesions.

METHODS: A total of 118 patients with 123 colorectal lesions examined by NBI endoscopy in the Zhejiang Provincial People’s Hospital from September 2008 to April 2010 were enrolled in this study. These lesions were classified by pit pattern and capillary pattern, and then assessed by histopathology.

RESULTS: Ten lesions not meeting the diagnostic criteria were excuded, the overall diagnostic accuracy of NBI endoscopy in distinguishing neoplasia from non-neoplasia colorectal lesions was 91.2% (103/113), and that of NBI endoscopy with and without high magnification was 93.0% (40/43) and 90.0% (63/70), respectively. Both were significantly higher than that of conventional colonoscopy reported in the literature (P < 0.05), but there was no significant difference between the two groups (P > 0.05).

CONCLUSION: Besides NBI magnifying endoscopy, NBI endoscopy without magnification may also be used to distinguish neoplasia from non-neoplasia colorectal lesions.

Changes in gastric mucosal patterns seen by magnifying NBI during H. pylori eradication

BACKGROUND

Magnifying narrow-band imaging (NBI) endoscopy visualizes superficial gastric mucosal and capillary patterns. We aimed to investigate changes in gastric mucosal patterns seen by magnifying NBI endoscopy after Helicobacter pylori eradication.

METHODS

Gastric mucosal patterns in non-pathological gastric corpus were observed by magnifying NBI endoscopy before and 12 weeks after H. pylori eradication in thirty patients. By using paired photographs of each case, changes in NBI mucosal patterns during H. pylori eradication were judged in a consensus manner by three blinded endoscopists.

RESULTS

At 12 weeks after H. pylori eradication, 20 of 24 subjects who had been successfully treated showed remarkable changes in gastric mucosal patterns (sensitivity 83.3%, specificity 100%). In the specimens from these subjects, the patterns of enlarged or elongated pits were improved to small oval or pinhole-like round pits, and the density of fine irregular vessels was decreased. Histological assessment showed alleviation of chronic inflammation in all subjects (p < 0.0001), while such a change was not observed for four subjects showing severe gastric atrophy and intestinal metaplasia. When the subjects were divided according to the presence of severe gastric atrophy, the diagnostic efficacy of magnifying NBI for predicting the results of H. pylori eradication was excellent in subjects without severe gastric atrophy and intestinal metaplasia (sensitivity and specificity, 100%). However, no change in the NBI mucosal pattern was observed in subjects with severe gastric atrophy and intestinal metaplasia, regardless of the H. pylori eradication result.

CONCLUSIONS

At least in subjects without severe gastric atrophy or intestinal metaplasia, successful H. pylori eradication treatment shows improvements in gastric mucosal patterns with the use of magnifying NBI endoscopy early after successful treatment.

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

BACKGROUND

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

AIMS

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Evaluation of microvessels in colorectal tumors by narrow band imaging magnification: including comparison with magnifying chromoendoscopy

BACKGROUND/AIMS

Narrow band imaging (NBI) magnification analysis has entered use in clinical settings to diagnose colorectal tumors. Pit pattern analysis with magnifying endoscopy is already widely used to assess colorectal lesions and invasion depth. Our study compared diagnoses by vascular pattern analysis and pit pattern analysis with NBI magnification.

METHODS

We examined 296 colorectal lesions-15 hyperplastic polyps (HP), 213 low-grade adenomas (L-Ad), 26 high-grade adenomas (H-Ad), 31 with intramucosal to scanty submucosal invasion (M-Sm-s), and 11 with massive submucosal invasion (Sm-m)-applying the system of Kudo et al. to analyze pit patterns, and the system of Tanaka et al. to analyze and classify vascular patterns by NBI into three categories: type A (hyperplasia pattern), type B (adenomatous pattern), and type C (carcinomatous pattern). Type C cases were subdivided into subtypes C1, C2, and C3. We used this system to examine histology type and invasion depth.

RESULTS

Diagnostic sensitivity, specificity, and accuracy were 100% for both type II pit pattern HP and type A HP. Diagnostic sensitivity, specificity, and accuracy were 85.4, 94.5, and 93.2% for Vi and Vn pit pattern cancer and 95.2, 91.7, and 92.2% for type C cancer (no significant differences in sensitivity, specificity, or accuracy). Diagnostic sensitivity, specificity, and accuracy were comparable for Vi high-grade irregularity and Vn pit pattern Sm-m (90.9, 96.8, and 96.7%) and type C2/C3 Sm-m (90.1, 98.2, and 98.0%), with no significant differences in sensitivity, specificity, or accuracy.

CONCLUSIONS

Vascular pattern analysis by NBI magnification proved comparable to pit pattern analysis.

Narrow-banding images and structures of microvessels of colonic lesions

BACKGROUND

Magnifying colonoscopy with NBI has been shown to be useful for the differential diagnosis of tumors. However, the relationship between findings on NBI magnification and the microvessel architecture of colorectal lesions remains to be clarified.

AIMS

The aim of this study was to clarify the correlation between NBI findings and the microvascular architecture of colorectal lesions according to the depth of microvessels from the mucosal surface.

METHODS

A total of 22 colorectal lesions (11 tubular adenomas and 11 hyperplasia) obtained from 22 patients were studied. These lesions were analyzed microscopically on tissue specimens immunostained with CD34. Three-dimensional images were reconstructed from serial sections of tubular adenomas, hyperplasia, and normal mucosa.

RESULTS

Three-dimensional reconstructed images of tubular adenoma and normal mucosa to a depth of less than 150 μm from the mucosal surface showed similar structures to images obtained by NBI magnification. Microvessel diameter was significantly larger in tubular adenoma than in normal mucosa (P = 0.002) and hyperplasia (P = 0.034), and microvessel area was significantly larger in tubular adenoma than in normal mucosa (P < 0.001) and hyperplasia (P < 0.001) only in the superficial mucosal layer (to a depth of less than 150 μm).

CONCLUSIONS

TA was characterized by thicker microvessels and higher volume of microvessels than NM and HP. Compared with white light, NBI can more accurately depict the characteristics of microvessels because it uses light with short wavelengths, thereby contributing to high diagnostic capability.

Development and validation of a training module on the use of narrow-band imaging in differentiation of small adenomas from hyperplastic colorectal polyps

BACKGROUND

Experts are accurate in differentiating small adenomas from hyperplastic polyps at colonoscopy by using narrow-band imaging (NBI).

OBJECTIVE

To prospectively evaluate the effectiveness of an NBI training module on individuals with varying colonoscopy experience.

DESIGN

Prospective educational evaluation study.

SETTING

Academic endoscopy unit.

PARTICIPANTS

Twenty-one participants of varying colonoscopy experience (novices, trainees, and experienced gastroenterologists) and 5 experts in NBI.

INTERVENTION

Participants completed a computer-based test module consisting of 30 NBI polyp images. No feedback was given. They then completed a computer-based training module on the use of NBI in the differentiation of adenomas and hyperplastic polyps. The test module was then completed a second time.

MAIN OUTCOME MEASUREMENTS

Construct validity (the difference in baseline accuracy on the test module between different groups of participants) and content validity (difference in accuracy achieved on the test module before and after training) of the training module.

RESULTS

There was a significant difference in the baseline accuracy (P < .001) between experts (0.95; 95% confidence interval [CI], 0.92-0.97), experienced colonoscopists (0.68; 95% CI, 0.68-0.74), trainees (0.75; 95% CI, 0.67-0.82), and novices (0.62; 95% CI, 0.46-0.77). Accuracy increased significantly (P < .001) for all 3 groups after training (novices 0.84; 95% CI, 0.78-0.88, trainees 0.90; 95% CI, 0.84-0.93, and experienced colonoscopists 0.84; 95% CI, 0.76-0.89). After training, the agreement was moderate at least (κ = 0.56 for novices, κ = 0.70 for trainees, and κ = 0.54 for experienced colonoscopists).

LIMITATIONS

This study did not assess the accuracy of optical diagnosis in routine clinical practice.

CONCLUSION

A short, computer-based training module can improve the diagnostic accuracy and interobserver agreement for the use of NBI to differentiate adenomas from hyperplastic polyps and could be used for the initial training in optical diagnosis.

Efficacy of magnifying endoscopy with flexible spectral imaging color enhancement in the diagnosis of colorectal tumors

BACKGROUND

Magnifying endoscopy with flexible spectral imaging color enhancement (FICE) is an image-enhanced endoscopy that captures the surface and vascular patterns of colorectal tumors. We evaluated and compared FICE magnification to narrow-band imaging (NBI) magnification.

METHODS

Flexible spectral imaging color enhancement or NBI magnification was performed to the visualize surface and vascular patterns of colorectal tumors, classified into 4 types: Type A, Type B, Type C1/C2, and Type C3, as previously reported. A total of 235 colorectal tumors were examined. The correlations between classifications found by FICE or NBI magnification and histopathological diagnoses were examined. Image evaluation was validated by assessing inter-observer and intra-observer agreements on examinations.

RESULTS

Twenty-eight hyperplastic polyps (HPs), 115 tubular adenomas (TAs), 72 mucosal and slightly invaded submucosal cancers (M-sSM), and 20 massively invaded submucosal cancers (mSM) were diagnosed. By FICE magnification, HP and TA were observed in 93.3 and 6.7% of Type A (15 lesions), respectively. TA, M-sSM, and HP were observed in 82.6, 15.4, and 2.0% of Type B (52 lesions),respectively. M-sSM, TA, and mSM were observed in 50.0,46.0, and 4.0% of Type C1/2 (50 lesions), respectively.mSMs were observed in all 7 Type C3 lesions. In diagnosing mSM in Type C3, the sensitivity and specificity of FICE magnification were 77.7 and 100%, respectively, compared to those of NBI, at 63.6 and 99.0%, respectively. Imaging evaluation was validated accurately by intra- and intraobserver measurements showing consistent results.

CONCLUSIONS

The classification of colorectal tumors by FICE magnification correlated well with the histopathological diagnoses, similar to findings for NBI magnification. FICE magnification can be evaluated accurately with the same diagnostic classifications as those used for NBI magnification.

Near-infrared fluorescence imaging using a protease-specific probe for the detection of colon tumors

BACKGROUND/AIMS

Early tumor detection is crucial for the prevention of colon cancer. Near-infrared fluorescence (NIRF) imaging using a target-activatable probe may permit earlier disease detection. Matrix metalloproteinases (MMPs) participate in tumorigenesis and tumor growth. The aim of this study was to determine whether NIRF imaging using an MMP-activatable probe can detect colon tumors at early stages.

METHODS

WE UTILIZED TWO MURINE COLON CANCER MODELS: a sporadic colon cancer model induced by azoxymethane (AOM), and a colitis-associated cancer model induced by a combination of AOM and dextran sodium sulfate (DSS). Colonic lesions were analyzed by histologic examination, Western blotting, immunohistochemical staining, and NIRF imaging using an MMP-activatable probe.

RESULTS

Multiple variable-sized tumors developed in both models and progressed from adenomas to adenocarcinomas over time. At the early stage of the AOM/DSS model, diffuse inflammation was observed within the tumors. MMP expression increased progressively through normal, inflammation, adenoma, and adenocarcionoma stages. NIRF signal intensities were strongly correlated with each tumor stage from adenoma to adenocarcinoma. NIRF imaging also distinguished tumors from inflamed mucosa.

CONCLUSIONS

NIRF imaging using a protease-activatable probe may be a useful tool for early tumor detection. This approach could translate to improve the endoscopic detection of colon tumors, especially in patients with inflammatory bowel disease.

High-definition and filter-aided colonoscopy

New high-resolution colonoscopes and filter technologies are allowing us to visualize more lesions and better characterize lesions within the gastrointestinal tract. In light of recent findings that flat and serrated lesions are more likely to contain invasive cancer and that even small lesions (5-10 mm) may contain advanced histology, detecting these lesions earlier with improved optical technologies may help decrease the rate of interval cancers after colonoscopy. With the limited accuracy of white-light colonoscopy (59%-84%) in distinguishing non-neoplastic lesions from neoplastic lesions, these new technologies can help us improve our abilities to risk stratify patients and determine more precise surveillance intervals.

Full-color skin imaging using RGB LED and floating lens in optical coherence tomography

The cosmetic industry has witnessed significant growth in recent years. Conventional hand-held skin cameras allow for 2D inspection of the skin surface. This paper proposes a new model for full-color 3D imaging of the skin tissue using fiber-based optical coherence tomography (OCT). Compared to laser or LD sources, RGB LED was found more suitable and thus chosen in the low-coherence interferometry due to its wider bandwidth. A floating objective lens was used to confocalize the R, G and B imaging planes and to derive a full-color image of the capillary system in the skin tissue. The skin imaging system can be miniaturized to form a new hand-held model using an RGB integrated source, a micro-interferometer module and a high-speed beam steering device. Non-invasive, full-color and hand-held skin imaging contributes to advances in the fields of skin science, dermatology and cosmetology.

The presence of large serrated polyps increases risk for colorectal cancer

BACKGROUND & AIMS

There is evidence that serrated polyps (serrated adenomas and hyperplastic polyps) have different malignant potential than traditional adenomas. We used a colonoscopy database to determine the association between the presence of serrated colorectal polyps and colorectal neoplasia.

METHODS

We performed a multicenter observational study of 10,199 subjects who underwent first-time colonoscopies. Data collected on study subjects included age and sex and the location, size, and histology of polyps or tumors found at colonoscopy. Serrated polyps were defined as those diagnosed by the pathologists in the participating hospitals as a serrated lesion (a lesion given the term of "classical hyperplastic polyp," "traditional serrated adenoma," "sessile serrated adenoma," or "mixed serrated polyp"). Large serrated polyps (LSPs) were defined as those ≥ 10 mm.

RESULTS

There were 1573 patients (15.4%) with advanced neoplasia, 708 patients (6.9%) with colorectal cancer (CRC), and 140 patients (1.4%) with LSPs in our cohort. Multivariate analysis associated the presence of LSPs with advanced neoplasia (odds ratio [OR], 4.01; 95% confidence interval [CI], 2.83-5.69) and CRC (OR, 3.34; 95% CI, 2.16-5.03). The presence of LSPs was the greatest risk factor for CRC, particularly for proximal CRC (OR, 4.79; 95% CI, 2.54-8.42). Proximal and protruded LSPs were the highest risk factors for proximal CRC (OR, 5.36; 95% CI, 2.40-10.8 and OR, 9.00; 95% CI, 2.75-19.2, respectively).

CONCLUSIONS

The presence of LSPs is a risk factor for CRC, particularly CRC of the proximal colon.

Autofluorescence imaging with a transparent hood for detection of colorectal neoplasms: a prospective, randomized trial

BACKGROUND

Colonoscopy is one of the most reliable methods for detection of colorectal neoplasms, but conventional colonoscopy can miss some lesions.

OBJECTIVE

To evaluate the efficacy of autofluorescence imaging (AFI) with a transparent hood (TH) for detection of colorectal neoplasms.

DESIGN

A 2 × 2 factorial designed, prospective, randomized, controlled trial.

SETTING

This study was conducted at the Osaka Medical Center for Cancer and Cardiovascular Diseases, a tertiary cancer center.

PATIENTS

A total of 561 patients.

INTERVENTIONS

Patients were allocated to 1 of 4 groups: (1) white light imaging (WLI) alone--colonoscopy using WLI without a TH; (2) WLI+TH--colonoscopy using WLI with a TH; (3) AFI alone--colonoscopy using AFI without a TH; and (4) AFI+TH--colonoscopy using AFI with a TH. Eight colonoscopists used each allocated method.

MAIN OUTCOME MEASUREMENT

The difference in neoplasm detection rate (number of detected neoplasms per patient) between the WLI alone and AFI+TH groups.

RESULTS

Neoplasm detection rate (95% confidence interval) in the AFI+TH group was significantly higher than in the WLI alone group (1.96 [1.50-2.43] vs 1.19 [0.93-1.44]; P = .023, Tukey-Kramer multiple comparison test). Relative detection ratios (95% confidence interval) for polypoid neoplasms based on Poisson regression model were significantly increased by mounting a TH (1.69 [1.34-2.12], P < .001), and relative detection ratios for flat neoplasms were significantly increased by AFI observation (1.83 [1.24-2.71], P = .002).

LIMITATIONS

Open trial performed in single cancer referral center.

CONCLUSION

AFI colonoscopy with a TH detected significantly more colorectal neoplasms than did conventional WLI colonoscopy without a TH.

Prevention of gastrointestinal cancer by surveillance endoscopy

The classification of the endoscopic appearance of superficial neoplastic lesions of the digestive mucosa aims to evaluate the risk of progression to advanced neoplasia in 3° (low, intermediate, high) and to predict appropriate treatment and corresponding surveillance. The privileged position of endoscopy results from its double impact on prevention of digestive cancer through reduction in incidence after early detection and eradication of precursors; and through reduction of mortality after detection and treatment of cancer at an early and curable stage. However the efficacy of diagnostic endoscopy still requires improvement and quality control on the following points: (1) technology, with a generalized use of the recently introduced high-resolution endoscopes. (2) diagnosis of poorly visible nonpolypoid precursors: this applies to small depressed lesions and large slightly elevated or sessile serrated and non-serrated precursors, particularly in the proximal colon. (3) treatment and training in therapeutic endoscopy, including the most recent techniques of mucosal resection of nonpolypoid lesions.

Differentiating adenomas from hyperplastic colorectal polyps: narrow-band imaging can be learned in 20 minutes

BACKGROUND

Colonoscopy with narrow-band imaging can allow real-time determination of polyp histology.

OBJECTIVE

To determine whether physicians with varying levels of experience can learn and apply endoscopic criteria to distinguish between adenomas and hyperplastic polyps.

DESIGN

Prospective observational study.

SETTING

University teaching hospital.

PARTICIPANTS

This study involved 37 physicians (medical residents, N = 12; gastroenterology fellows, N = 12; and gastroenterology faculty, N = 13).

INTERVENTION

Small-group, 20-minute, didactic teaching sessions in which the endoscopic criteria for determining polyp histology by using narrow-band imaging were described and demonstrated.

MAIN OUTCOME MEASUREMENTS

Learning outcomes were evaluated by using written pretests and posttests in which participants scored pathologically verified, high-definition polyp photographs as adenomas or hyperplastic polyps.

RESULTS

The mean overall scores increased significantly from 47.6% correct on the pretest to 90.8% correct on the posttest (P = .0001). The overall mean percentage of responses answered don't know was significantly lower on the posttest (0.6%) compared with the pretest (20.5%, P < .0001). After training, the level of agreement was substantial (kappa = 0.69 for all participants, kappa = 0.79 for fellows).

LIMITATIONS

Our study did not assess for sustained improvement with time or in vivo accuracy of histological prediction during live colonoscopy. Further validation in a sample of community physicians is required.

CONCLUSION

A short, didactic teaching session can achieve high accuracy and good interobserver agreement in the use of narrow-band imaging for determining the histology of colorectal polyps.

Characterization of colorectal tumors using narrow-band imaging magnification: combined diagnosis with both pit pattern and microvessel features

OBJECTIVE

We aimed to clarify the clinical usefulness of narrow-band imaging (NBI) magnification for evaluating both pit appearances and microvessel architecture in comparison with evaluation of microvessel architecture alone in invasion depth of colorectal tumors.

MATERIAL AND METHODS

A total of 189 colorectal lesions [37 adenomas, 73 intramucosal to scanty submucosal invasive carcinomas and 79 massive submucosal invasive (SM-m) carcinomas] were analyzed. All lesions showing irregular pit structure were observed by NBI magnifying endoscopy. Based on both pit appearance and microvessel features, lesions were classified into three grades (C1, C2, C3), as described previously. Also, lesions were classified as high or low by microvessel irregularity. Furthermore, the histopathological background and the inter- and intraobserver variability of C subtype were assessed.

RESULTS

The SM-m rate of C1, C2 and C3 was 5.2, 60.5 and 92.7%, respectively. On the other hand, SM-m rate of lesion with mildly and highly irregular vessels was 13.3 and 55.0%, respectively. For the histopathological background, a high percentage of destruction of the glandular orifice, disappearance of the lamina muscularis mucosae and superficial exposure of desmoplastic reaction (DR) were observed in type C3. For C subtype classification of NBI magnification findings, the kappa value for interobserver variability was 0.749, and the kappa value for intraobserver variability was 0.745.

CONCLUSIONS

NBI magnification findings evaluated by both pit appearances and microvessel features (C subtype) showing a good kappa value in variability are more useful in invasion depth diagnosis of colorectal tumor than those evaluated by microvessel features alone.

Prospective randomized controlled trial evaluating cap-assisted colonoscopy vs standard colonoscopy

AIM: To study the significance of cap-fitted colonoscopy in improving cecal intubation time and polyp detection rate.

METHODS: This study was a prospective randomized controlled trial conducted from March 2008 to February 2009 in a tertiary referral hospital at Sydney. The primary end point was cecal intubation time and the secondary endpoint was polyp detection rate. Consecutive cases of total colonoscopy over a 1-year period were recruited. Randomization into either standard colonoscopy (SC) or cap-assisted colonoscopy (CAC) was performed after consent was obtained. For cases randomized to CAC, one of the three sizes of cap was used: D-201-15004 (with a diameter of 15.3 mm), D-201-14304 (14.6 mm) and D-201-12704 (13.0 mm). All of these caps were produced by Olympus Medical Systems, Japan. Independent predictors for faster cecal time and better polyp detection rate were also determined from this study.

RESULTS: There were 200 cases in each group. There was no significant difference in terms of demographic characteristics between the two groups. CAC, when compared to the SC group, had no significant difference in terms of cecal intubation rate (96.0% vs 97.0%, P = 0.40) and time (9.94 ± 7.05 min vs 10.34 ± 6.82 min, P = 0.21), or polyp detection rate (32.8% vs 31.3%, P = 0.75). On the subgroup analysis, there was no significant difference in terms of cecal intubation time by trainees (88.1% vs 84.8%, P = 0.40), ileal intubation rate (82.5% vs 79.0%, P = 0.38) or total colonoscopy time (23.24 ± 13.95 min vs 22.56 ± 9.94 min, P = 0.88). On multivariate analysis, the independent determinants of faster cecal time were consultant-performed procedures (P < 0.001), male patients (P < 0.001), non-usage of hyoscine (P < 0.001) and better bowel preparation (P = 0.01). The determinants of better polyp detection rate were older age (P < 0.001), no history of previous abdominal surgery (P = 0.04), patients not having esophagogastroduodenoscopy in the same setting (P = 0.003), trainee-performed procedures (P = 0.01), usage of hyoscine (P = 0.01) and procedures performed for polyp follow-up (P = 0.01). The limitations of the study were that it was a single-center experience, no blinding was possible, and there were a large number of endoscopists.

CONCLUSION: CAC did not significantly different from SC in term of cecal intubation time and polyp detection rate.

A prospective randomized study on computed virtual chromoendoscopy versus conventional colonoscopy for the detection of small colorectal adenomas

BACKGROUND

Colonoscopy is considered to be the standard diagnostic test for detecting colonic neoplasia, particularly for small lesions. However, recent publications have suggested that 15-27% of small adenomas might be missed during conventional colonoscopy.

AIMS

To determine whether computed virtual chromoendoscopy (CVC) can improve the detection of small adenomas as compared to conventional colonoscopy.

METHODS

We examined 135 consecutive patients by total colonoscopy and 128 patients were randomized to compare white-light colonoscopy (65 patients) and CVC-mode colonoscopy (63 patients) after the exclusion of seven patients because of poor bowel preparation (n = 4) or other causes (one sigmoid colon cancer, two intestinal tuberculosis).

RESULTS

There were no differences between the patient characteristics for the two study groups, i.e., age, sex, body mass index, quality of bowel preparations, indications for the procedure, conscious sedation, and examination times-both insertion time and withdrawal time. The groups did not differ in the number of patients with all polyps, adenomas, or hyperplastic polyps. In the patients with adenomas, however, there was a significant difference in the detection rate for the patients with small adenomas less than 5 mm in size (P = 0.006).

CONCLUSIONS

Colonoscopy with the CVC mode identified more patients with small colorectal adenomas than conventional white-light colonoscopy. Therefore, CVC might be a supplementary tool aiding the colonoscopist in the detection of small adenomas; however, further studies will need to demonstrate whether these results are reproducible across patients in varied clinical settings.

Impact of narrow-band imaging in screening colonoscopy

Narrow band-imaging (NBI) enhances mucosal visualization of the vascular network and surface structure and helps to increase the visibility of neoplasia by improving contrast. Studies on the detectability of colorectal neoplastic lesions using NBI have primarily been reported in Western countries, but the published opinions and conclusions remain controversial at the present time. Our earlier prospective pilot study demonstrated that NBI colonoscopy significantly improved detection of flat lesions, which are more likely to be missed, particularly on the right side of the colon. It is especially important that even examiners performing routine screening colonoscopies become sufficiently familiar with flat and depressed lesions and then take full advantage of the endoscopic systems and specific image enhancement functions currently available for improved detection of flat and diminutive lesions. Adequate bowel preparation is another important consideration.

Diagnostic accuracy of narrow-band imaging and pit pattern analysis significantly improved for less-experienced endoscopists after an expanded training program

BACKGROUND

Previous reports assessing diagnostic skill using narrow-band imaging (NBI) and pit pattern analysis for colorectal polyps involved only highly experienced endoscopists.

OBJECTIVE

To evaluate diagnostic skills of less-experienced endoscopists (LEE group) for differentiation of diminutive colorectal polyps by using NBI and pit pattern analysis with and without magnification after an expanded training program.

DESIGN

Prospective study.

PATIENTS

This study involved 32 patients with 44 colorectal polyps (27 adenomas and 17 hyperplastic polyps) of < or =5 mm that were identified and analyzed by using conventional colonoscopy as well as non-magnification and magnification NBI and chromoendoscopy followed by endoscopic removal for histopathological analysis.

INTERVENTION

Before a training course, 220 endoscopic images were distributed in randomized order to residents with no prior endoscopy experience (NEE group) and to the LEE group, who had performed colonoscopies for more than 5 years but had never used NBI. The 220 images were also distributed to highly experienced endoscopists (HEE group) who had routinely used NBI for more than 5 years. The images were distributed to the NEE and LEE groups again after a training class. Magnification NBI and chromoendoscopy images were assessed by using the Sano and Kudo classification systems, respectively.

MAIN OUTCOME MEASUREMENTS

Diagnostic accuracy and interobserver agreement for each endoscopic modality in each group.

RESULTS

Diagnostic accuracy was significantly higher, and kappa (kappa) values improved in the LEE group for NBI with high magnification after expanded training. Diagnostic accuracy and kappa values when using high-magnification NBI were highest among endoscopic techniques for the LEE group after such training and the HEE group (accuracy 90% vs 93%; kappa = 0.79 vs 0.85, respectively).

LIMITATIONS

Study involved only polyps of < or =5 mm.

CONCLUSION

Using high-magnification NBI increased the differential diagnostic skill of the LEE group after expanded training so that it was equivalent to that of the HEE group.

Meshed capillary vessels found on narrow-band imaging without optical magnification effectively identifies colorectal neoplasia: a North American validation of the Japanese experience

BACKGROUND

The presence of meshed capillary (MC) vessels is highly sensitive (96%) and specific (92%) for diagnosing colorectal neoplasia on colonoscopy by using narrow-band imaging (NBI) with optical magnification, which is not available in North America. However, the efficacy of NBI to identify an MC pattern without optical magnification has not been determined.

OBJECTIVE

To determine the diagnostic capabilities of NBI colonoscopy without optical magnification in differentiating neoplastic from non-neoplastic colorectal polyps by using the MC pattern.

DESIGN

Retrospective comparison of prospectively collected colorectal polyp data.

SETTING

Large, academic medical center.

PATIENTS

This study involved 126 consecutive colorectal polyps (median size 3 mm) that were found in 52 patients (33 men) with a median age of 59.5 years.

INTERVENTION

All lesions identified by white-light colonoscopy were prospectively diagnosed in real-time by using the MC pattern as determined on high-definition NBI, with 1.5x zoom but without true optical magnification, and then endoscopically excised. Surgical pathology was used as the criterion standard.

MAIN OUTCOME MEASUREMENTS

Sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of identifying neoplastic polyps were calculated.

RESULTS

NBI without optical magnification was found to have a sensitivity of 93%, specificity of 88%, positive predictive value of 90%, negative predictive value of 91%, and diagnostic accuracy of 91% when all polyp sizes were considered. For lesions < or =5 mm, sensitivity was 87%, specificity was 93%, positive predictive value was 89%, negative predictive value was 91%, and diagnostic accuracy was 90%.

LIMITATIONS

Single-center, single-endoscopist experience.

CONCLUSION

Use of the MC pattern on NBI colonoscopy without optical magnification effectively distinguishes neoplastic from non-neoplastic colorectal polyps. NBI colonoscopy without optical magnification for neoplastic polyp diagnosis appears to be comparable with NBI with optical magnification when the MC pattern is used. A large, prospective trial is needed for further validation.

Surveillance colonoscopy using a transparent hood and image-enhanced endoscopy

Colonoscopists can miss adenomas during colonoscopy screening. A transparent hood attached to the tip of the colonoscope helps detection of colorectal adenomas, but as far as we are aware, there has been no trial indicating its statistically significant effectiveness. Total colonic dye spray might improve the adenoma detection rate but it is complicated and time-consuming for routine clinical usage. Moreover, the efficacy of narrow band imaging for detection of colorectal adenoma is controversial and is still under debate. Autofluorescence imaging (AFI) might be better able to detect flat lesions than white light imaging (WLI), but its ability is influenced easily by the area of the observation. Therefore, we have attached a transparent hood to the tip of an AFI colonoscope during colonoscopy screening in clinical usage. AFI can detect a flat lesion, which is difficult to detect using WLI. A transparent hood can help to detect lesions behind the folds by pushing the colonic fold. We expect that mounting a transparent hood would work complimentary to AFI. Further improvements, including a combination of AFI and a transparent hood, are needed and they would provide optimal surveillance intervals.

Indications for endoscopic resection of colorectal polyps and surveillance guidelines

We report three keynote lecture presentations from the Endoscopic Forum Japan 2009 at Otaru, Hokkaido, on 1-2 August 2009. We will discuss herein: (i) colorectal cancer screening focusing on a comparison between the National Polyp Study and the Japan Polyp Study; (ii) how to deal with small polyps <5 mm in diameter; (iii) the natural history of colorectal tumor development; (iv) the importance of follow up for local recurrence after endoscopic resection for colorectal polyps; and (v) screening for colorectal cancer using two new modalities, narrow-band imaging and autofluorescence imaging. A questionnaire was completed by everyone involved in the conference and the most important results were reported and then discussed by the participants.

Effectiveness of narrow-band imaging magnification for invasion depth in early colorectal cancer

AIM

To evaluate the surface microvascular patterns of early colorectal cancer (ECC) using narrow-band imaging (NBI) with magnification and its effectiveness for invasion depth diagnosis.

METHODS

We studied 112 ECC lesions [mucosal/submucosal superficial (m/sm-s), 69; sm-deep (sm-d), 43] > or = 10 mm that subsequently underwent endoscopic or surgical treatment at our hospital. We compared microvascular architecture revealed by NBI with magnification to histological findings and then to magnification colonoscopy pit pattern diagnosis.

RESULTS

Univariate analysis indicated vessel density: non-dense (P < 0.0001); vessel regularity: negative (P < 0.0001); caliber regularity: negative (P < 0.0001); vessel length: short (P < 0.0001); and vessel meandering: positive (P = 0.002) occurred significantly more often with sm-d invasion than m/sm-s invasion. Multivariate analysis showed sm-d invasion was independently associated with vessel density: non-dense [odds ratio (OR) = 402.5, 95% confidence interval (CI): 12.4-13 133.1] and vessel regularity: negative (OR = 15.9, 95% CI: 1.2-219.1). Both of these findings when combined were an indicator of sm-d invasion with sensitivity, specificity and accuracy of 81.4%, 100% and 92.9%, respectively. Pit pattern diagnosis sensitivity, specificity and accuracy, meanwhile, were 86.0%, 98.6% and 93.8%, respectively, thus, the NBI with magnification findings of non-dense vessel density and negative vessel regularity when combined together were comparable to pit pattern diagnosis.

CONCLUSION

Non-dense vessel density and/or negative vessel regularity observed by NBI with magnification could be indicators of ECC sm-d invasion.

Hood-assisted colonoscopy is more effective in detection of colorectal adenomas than narrow-band imaging

BACKGROUND & AIMS

Colonoscopy, using either a transparent retractable extension device or narrow band imaging, is thought to improve colon adenoma detection. We compared the abilities of a transparent retractable extension device and narrow band imaging to detect colorectal adenomas.

METHODS

One hundred and seven patients with colonic adenomas that were detected by traditional colonoscopy were randomly assigned to groups that underwent a second colonoscopy that used either a transparent retractable extension or narrow band imaging; adenomas were removed. The principal outcome parameters were the number, size, shape, and location of adenomas detected. The patients' demographic characteristics, indications for colonoscopy, and cecal intubation times were similar between groups.

RESULTS

Use of the transparent retractable extension resulted in detection of 31% more adenomas than the initial procedure (P < .0001). The majority of newly discovered adenomas were sessile (79%; 26/33) and less than 5 mm in size (73%; 24/33). There was no significant increase in adenoma detection (5%) between first colonoscopy and second colonoscopy using narrow band imaging. Additional adenomas were found in 40.7% of patients that were examined using the transparent hood (22/54) versus 13.2% of those examined using narrow band imaging (7/53) (P = .0028).

CONCLUSIONS

Colonoscopy with a transparent retractable extension significantly improved the adenoma detection rate compared with repeat colonoscopy using narrow band imaging.

Efficacy of capillary pattern type IIIA/IIIB by magnifying narrow band imaging for estimating depth of invasion of early colorectal neoplasms

Background

Capillary patterns (CP) observed by magnifying Narrow Band Imaging (NBI) are useful for differentiating non-adenomatous from adenomatous colorectal polyps. However, there are few studies concerning the effectiveness of magnifying NBI for determining the depth of invasion in early colorectal neoplasms. We aimed to determine whether CP type IIIA/IIIB identified by magnifying NBI is effective for estimating the depth of invasion in early colorectal neoplasms.

Methods

A series of 127 consecutive patients with 130 colorectal lesions were evaluated from October 2005 to October 2007 at the National Cancer Center Hospital East, Chiba, Japan. Lesions were classified as CP type IIIA or type IIIB according to the NBI CP classification. Lesions were histopathologically evaluated. Inter and intraobserver variabilities were assessed by three colonoscopists experienced in NBI.

Results

There were 15 adenomas, 66 intramucosal cancers (pM) and 49 submucosal cancers (pSM): 16 pSM superficial (pSM1) and 33 pSM deep cancers (pSM2-3). Among lesions diagnosed as CP IIIA 86 out of 91 (94.5%) were adenomas, pM-ca, or pSM1; among lesions diagnosed as CP IIIB 28 out of 39 (72%) were pSM2-3. Sensitivity, specificity and diagnostic accuracy of the CP type III for differentiating pM-ca or pSM1 (<1000 μm) from pSM2-3 (≥1000 μm) were 84.8%, 88.7 % and 87.7%, respectively. Interobserver variability: κ = 0.68, 0.67, 0.72. Intraobserver agreement: κ = 0.79, 0.76, 0.75

Conclusion

Identification of CP type IIIA/IIIB by magnifying NBI is useful for estimating the depth of invasion of early colorectal neoplasms.

Magnifying narrow-band imaging versus magnifying white-light imaging for the differential diagnosis of gastric small depressive lesions: a prospective study

BACKGROUND

The accurate diagnosis of gastric small depressive lesions (SDLs), including gastritis and cancerous lesions, is difficult with conventional endoscopy when using white-light imaging (WLI). Narrow-band imaging (NBI) is expected to make a more accurate diagnosis of gastric SDLs than WLI because it provides better visualization of the mucosal surface and microvascular architecture when combined with magnifying endoscopy.

OBJECTIVE

To compare the real-time diagnostic accuracy of magnifying WLI and magnifying NBI for gastric SDLs.

DESIGN

Prospective study.

SETTING

National Cancer Center Hospital East, Kashiwa, Japan.

PATIENTS

Fifty-seven lesions in 53 consecutive patients were analyzed: 30 cancers and 27 benign lesions.

INTERVENTIONS

If previously undiagnosed gastric SDLs smaller than 10 mm were identified during an endoscopic examination, magnifying observation with both WLI and NBI was performed for each SDL. Endoscopic diagnosis of SDLs was made by each method on site.

MAIN OUTCOME MEASUREMENTS

The diagnostic accuracy and the time required for diagnosis.

RESULTS

The diagnostic accuracy was significantly higher for NBI than for WLI (79% vs 44%; P = .0001), as was its sensitivity (70% vs 33%; P = .0005). The diagnostic specificity of NBI (89%) was higher than that of WLI (67%), but the difference was not statistically significant. The time required for the diagnosis was equivalent with both methods.

LIMITATIONS

Single-center study, small sample size.

CONCLUSIONS

Adding NBI to the WLI examination is essential for making an accurate diagnosis of gastric SDLs compared with magnifying WLI alone. (UMIN Clinical Trials Registry identification number C000000421).

Narrow Band Imaging and Autofluorescence Imaging for the Detection and Optical Diagnosis of Colorectal Polyps

Colorectal cancer is the most common cancer in Singapore and polyps which are detected during screening colonoscopy are routinely removed. Conventional white light colonoscopy has a substantial miss-rate for polyps and limited accuracy in differentiating neoplastic from non-neoplastic polyps. Dye-based chromoendoscopy and more recent equipment-based image enhanced endoscopic techniques such as narrow-band imaging (NBI) and autofluorescence imaging (AFI) are promising tools to improve polyp detection and optical diagnosis. Current evidence suggests that NBI may not be superior compared to high definition white-light for polyp detection, but it achieves excellent accuracy in polyp characterisation, approaching that of histopathology. AFI is a wide area scanning modality which functions as a red-flag technique to improve polyp detection, although the evidence is still evolving. The ability to accurately characterise polyps with NBI and AFI will guide the management of polyps and in some cases, avoid unnecessary polypectomy and routine histopathology. This has potential to reduce associated costs and risks of polypectomy, and improves on overall efficiency of screening colonoscopy. The review will discuss the technology, current evidence and the issues relevant to the role of NBI and AFI for the detection and optical diagnosis of polyps in colorectal cancer screening.

Early detection of superficial squamous cell carcinoma in the head and neck region and esophagus by narrow band imaging: a multicenter randomized controlled trial

PURPOSE

Most of the esophageal squamous cell carcinomas (ESCCs) and cancers of the head and neck (H&N) region are diagnosed at later stages. To achieve better survival, early detection is necessary. We compared the real-time diagnostic yield of superficial cancer in these regions between conventional white light imaging (WLI) and narrow band imaging (NBI) in high-risk patients.

PATIENTS AND METHODS

In a multicenter, prospective, randomized controlled trial, 320 patients with ESCC were randomly assigned to primary WLI followed by NBI (n = 162) or primary NBI followed by WLI (n = 158) in a back-to-back fashion. The primary aim was to compare the real-time detection rates of superficial cancer in the H&N region and the esophagus between WLI and NBI. The secondary aim was to evaluate the diagnostic accuracy of these techniques.

RESULTS

NBI detected superficial cancer more frequently than did WLI in both the H&N region and the esophagus (100% v 8%, P < .001; 97% v 55%, P < .001, respectively). The sensitivity of NBI for diagnosis of superficial cancer was 100% and 97.2% in the H&N region and the esophagus, respectively. The accuracy of NBI for diagnosis of superficial cancer was 86.7% and 88.9% in these regions, respectively. The sensitivity and accuracy were significantly higher using NBI than WLI in both regions (P < .001 and P = .02 for the H&N region; P < .001 for both measures for the esophagus, respectively).

CONCLUSION

NBI could be the standard examination for the early detection of superficial cancer in the H&N region and the esophagus.

Time-gated fluorescence spectroscopy improves endoscopic detection of low-grade dysplasia in ulcerative colitis

BACKGROUND

Dysplasia in ulcerative colitis is frequently missed with 4-quadrant biopsies. An experimental setup recording delayed fluorescence spectra simultaneously with white light endoscopy was recently developed.

OBJECTIVE

We compared detection of invisible flat intraepithelial neoplasia with protoporphyrin IX fluorescence and standard 4-quadrant biopsies.

DESIGN

Prospective, crossover design without randomization of the order of procedures.

SETTING

Gastroenterology Department, Humboldt University, Charité, Berlin, Germany.

PATIENTS

Forty-two patients with extensive ulcerative colitis of more than 10 years' duration were included.

INTERVENTIONS

Colonoscopy with 4-quadrant biopsies and targeted biopsies of macroscopic lesions and time-gated fluorescence-guided colonoscopy were performed 2 weeks apart by 2 blinded endoscopists. Three independent pathologists examined the biopsy specimens.

MAIN OUTCOME MEASUREMENTS

The primary outcome criterion was detection rate of invisible flat intraepithelial neoplasia.

RESULTS

Invisible flat intraepithelial neoplasia was detected in 3 (7%) patients by white light 4-quadrant biopsies and in 10 (24%) patients by fluorescence-guided endoscopy (P = .02). The sensitivity and specificity for differentiating patients with and without dysplasia were 100% and 81%, respectively. Dysplastic and nondysplastic mucosa could be discriminated with a sensitivity and specificity of 73% and 81%, respectively.

LIMITATIONS

The trial was not randomized.

CONCLUSION

The detection rate of intraepithelial neoplasia in patients with ulcerative colitis can be improved by fluorescence-guided colonoscopy.