Prospective study of early detection of pharyngeal superficial carcinoma with the narrowband imaging laryngoscope

Clinical significance of type IV vascularization of laryngeal lesions according to the Ni classification

Background

Scattered, small, dot-like intraepithelial papillary capillary loops (IPCLs) represent type IV epithelial vascularization according to "Ni classification" and are considered to be nonmalignant. According to the European Laryngological Society classification, these loops are malignant vascular changes. This contradiction has high clinical importance; therefore, clarification of the clinical significance of type IV vascularization according to the Ni classification is needed.

Methods

The study was performed between June 2015 and December 2022. All recruited patients (n = 434) were symptomatic, with macroscopic laryngeal lesions (n = 674). Patients were investigated using the enhanced endoscopic methods of narrow band imaging (NBI) and the Storz Professional Image Enhancement System (IMAGE1 S). The microvascular patterns in the lesions were categorized according to Ni classification from 2011 and all lesions were examined histologically.

Results

A total of 674 lesions (434 patients) were investigated using flexible NBI endoscopy and IMAGE1 S endoscopy. Type IV vascularization was recognized in 293/674 (43.5%) lesions. Among these 293 lesions, 178 (60.7%) were benign (chronic laryngitis, hyperplasia, hyperkeratosis, polyps, cysts, granulomas, Reinkeho oedema and recurrent respiratory papillomatosis); 9 (3.1%) were squamous cell carcinoma; 61 (20.8%) were mildly dysplastic, 29 (9.9%) were moderately dysplastic, 14 (4.8%) were severe dysplastic and 2 (0.7%) were carcinoma in situ. The ability to recognize histologically benign lesions in group of nonmalignant vascular pattern according to Ni (vascularization type I-IV) and distinguish them from precancers and malignancies was with accuracy 75.5%, sensitivity 54.4%, specificity 94.4%, positive predictive value 89.6% and negative predictive value 69.9%.

Conclusion

Laryngeal lesions with type IV vascularization as defined by Ni present various histological findings, including precancerous and malignant lesions. Patients with type IV vascularization must be followed carefully and, in case of progression mucosal lesion microlaryngoscopy and excision are indicated.

A comparison of the efficacy of narrow band imaging and contact endoscopy in an early diagnosis of squamous malignancies of the upper aerodigestive tract

Background

This study aims to compare the efficacy of narrow band imaging (NBI) endoscopy and contact endoscopy in early diagnosis of squamous malignancies of upper aerodigestive tract.

Methods

This study was of 18 months duration, sample size 50, and carried out at tertiary care hospital. The patients were subjected initially to NBI endoscopy followed by contact endoscopy. Thereafter, the lesion was biopsied and subjected to histopathological examination as is done routinely. The images obtained were analyzed based on criteria proposed by earlier studies and compared with histopathological examination as gold standard.

Results

The sensitivity, specificity, and negative predictive values of NBI in early diagnosis of squamous malignancies of upper aerodigestive tract were high and better than contact endoscopy.

Conclusion

Endoscopic NBI is a noninvasive and promising tool used for in vivo differentiation between malignant and nonmalignant lesions of upper aerodigestive tract by using morphology of mucosal capillaries and is more efficacious than contact endoscopy. It can be employed as part of routine ENT examination in outpatient departments; however, it has got a learning curve associated with it.

Risk factors for adverse events associated with endoscopic submucosal dissection for superficial pharyngeal cancer

BACKGROUND

Superficial pharyngeal cancer can be treated with curative intent while preserving function using minimally invasive peroral endoscopic resection techniques such as endoscopic submucosal dissection (ESD). However, severe adverse events occasionally occur, such as laryngeal edema requiring temporary tracheotomy and fistula formation. Therefore, we investigated the risk factors for adverse events associated with ESD for superficial pharyngeal cancer.

METHODS

This retrospective observational study was conducted at a single institution, and 63 patients who underwent ESD were enrolled. The primary outcome was the risk factors for adverse events associated with ESD. The secondary outcomes were adverse events associated with ESD and their frequency.

RESULTS

The overall adverse event rate was 15.9% (10/63). The incidence of laryngeal edema requiring prophylactic temporary tracheotomy was 11.1%, while laryngeal edema requiring emergency temporary tracheotomy, postoperative bleeding, aspiration pneumonia, fistula, abscess, and stricture formation occurred in 1.6% of patients, respectively. Logistic regression analyses showed that a history of radiotherapy for head and neck cancer was a risk factor for adverse events (odds ratio [OR], 16.67; 95% confidence interval [CI], 3.04-91.34; p = 0.001). After adjusting the model for differences in the baseline risk factors using the inverse probability of treatment weighting method, the adverse events were found to increase in association with a history of radiotherapy for head and neck cancer (OR, 39.66; 95% CI,5.85-268.72; p < 0.001).

CONCLUSION

History of radiotherapy for head and neck cancer is an independent risk factor for adverse events associated with ESD for superficial pharyngeal cancer. Among adverse events, laryngeal edema requiring prophylactic temporary tracheotomy was particularly high.

Intraoperative Imaging Techniques to Improve Surgical Resection Margins of Oropharyngeal Squamous Cell Cancer: A Comprehensive Review of Current Literature

Inadequate resection margins in head and neck squamous cell carcinoma surgery necessitate adjuvant therapies such as re-resection and radiotherapy with or without chemotherapy and imply increasing morbidity and worse prognosis. On the other hand, taking larger margins by extending the resection also leads to avoidable increased morbidity. Oropharyngeal squamous cell carcinomas (OPSCCs) are often difficult to access; resections are limited by anatomy and functionality and thus carry an increased risk for close or positive margins. Therefore, there is a need to improve intraoperative assessment of resection margins. Several intraoperative techniques are available, but these often lead to prolonged operative time and are only suitable for a subgroup of patients. In recent years, new diagnostic tools have been the subject of investigation. This study reviews the available literature on intraoperative techniques to improve resection margins for OPSCCs. A literature search was performed in Embase, PubMed, and Cochrane. Narrow band imaging (NBI), high-resolution microendoscopic imaging, confocal laser endomicroscopy, frozen section analysis (FSA), ultrasound (US), computed tomography scan (CT), (auto) fluorescence imaging (FI), and augmented reality (AR) have all been used for OPSCC. NBI, FSA, and US are most commonly used and increase the rate of negative margins. Other techniques will become available in the future, of which fluorescence imaging has high potential for use with OPSCC.

Outcomes of Endoscopic Submucosal Dissection for Treatment of Superficial Pharyngeal Cancers: Systematic Review and Meta-Analysis

BACKGROUND AND AIMS

Studies evaluating the role of endoscopic submucosal dissection (ESD) in the management of superficial pharyngeal cancers have reported promising results. This meta-analysis evaluates the efficacy and safety of ESD in the management of superficial pharyngeal cancers.

METHODS

We reviewed several databases from inception to September 03, 2020, to identify studies evaluating the efficacy and safety of ESD in the management of superficial pharyngeal cancers. Our outcomes of interest were en bloc resection rate, complete resection rate, adverse events, and rates of local recurrence. Pooled rates with 95% confidence intervals (CI) for all outcomes were calculated using random-effect model. Heterogeneity was assessed by I² statistic. We assessed publication bias by using funnel plots and Egger's test. We conducted meta-regression analysis to explore heterogeneity in analyses.

RESULTS

Ten studies were included in analyses. All studies were from Asia. Pooled rates (95% CI) for en bloc resection and complete resection were 94% (87%, 97%) and 72% (62%, 80%), respectively. The pooled rates (95% CI) for adverse events and local recurrence were 10% (5%, 17%) and 1.9% (0.9%, 4%), respectively. Most of the analyses were limited by substantial heterogeneity. On meta-regression analysis, the heterogeneity was explained by size of tumor and histology. Funnel plots and Egger's test showed no evidence of publication bias.

CONCLUSIONS

This meta-analysis including studies from Asian countries demonstrated that ESD is an efficacious and safe option in the management of superficial pharyngeal cancers. More studies and studies from Western countries are needed to further validate these findings.

Tumor detection with transoral use of flexible endoscopy for unknown primary head and neck cancer

OBJECTIVES

With the advent of new optical technologies, early pharyngolaryngeal cancerous lesions can be better visualized. Although the conventional transnasal approach offers great views of the hypopharynx and larynx, the visualization of the oropharynx and palatine tonsils is limited. Through the transoral insertion of a flexible video-laryngoscope, direct views of the oropharynx and oral cavity can be obtained. Thus, transoral examination may contribute to primary detection of cancers of unknown primary (CUP).

METHODS

Eighty-five CUP patients from Tokai University were included retrospectively in this study, from 2006 to 2017. Starting in 2010, we employed the transoral examination in addition to our conventional method. The primary detection rates were compared before and after 2010. Oropharyngeal primaries were further analyzed for tumor subsite and p16 status.

RESULTS

The overall primary detection rate did not improve with the addition of transoral examination. However, greater numbers of oropharyngeal primaries were detected. The oropharyngeal lesions detected by transoral examination were mainly p16 positive, located on the palatine tonsil.

CONCLUSION

Transoral examination is a noninvasive, easy method to adopt in an outpatient setting, and a promising technique to improve tumor detection in this era of human papillomavirus-associated head and neck cancers.

LEVEL OF EVIDENCE

3.

Diagnostic Accuracy of Narrow Band Imaging in Patients with Oral Lichen Planus: A Prospective Study

OBJECTIVE

Oral lichen planus (OLP) is a chronic mucocutaneous immune-mediated disease affecting 1% to 4% of the worldwide population. Development of malignant lesions is reported but only affects a minority of patients. The aim of our study was to assess the diagnostic potential of narrow band imaging (NBI) in OLP patients; focusing on the identification of high-grade dysplasia/carcinoma in newly developed lesions.

METHODS

Prospective evaluation of 56 patients with histopathologic diagnosis of OLP and presenting newly developed lesions not responding to medical treatment. All lesions were assessed by high-definition (HD) white light (WL) and HD-NBI endoscopy. All patients underwent biopsy regardless of the appearance at HD-WL and HD-NBI. Histology was defined as "positive" in case of high-grade dysplasia or carcinoma.

RESULTS

Five lesions (9%) were diagnosed as high-grade dysplasia/carcinoma. In this setting, overall diagnostic potential of HD-NBI was optimal, with a sensitivity of 100% (95% CI, 48-100), specificity of 96% (95% CI, 86-99), negative predictive value of 100% (95% CI, not calculable), positive predictive value of 71% (95% CI, 39-91), and accuracy of 96% (95% CI, 88-100).

CONCLUSIONS

Despite the diffuse inflammatory pattern derived from OLP, NBI improved the diagnostic accuracy and the capability to detect high-grade dysplasia/carcinoma.

LEVEL OF EVIDENCE

4 Laryngoscope, 131:E1156-E1161, 2021.

Narrowband Imaging for p16+ Unknown Primary Squamous Cell Carcinoma Prior to Transoral Robotic Surgery

Our purpose was to assess the potential utility of narrowband imaging (NBI) as a tool in diagnosing and treating unknown primary oropharyngeal squamous cell carcinoma (OPSCC) in patients prior to diagnostic resection with transoral robotic surgery (TORS). Between 2016 and March 2019, 29 patients with carcinoma of unknown primary meeting inclusion criteria were identified and treated with TORS. NBI was used preoperatively in 9 of 29 patients. A suspected tumor site was delineated by NBI in 8 of 9 patients (89%). Of the patients imaged with NBI, 8 of 9 (89%) patients had a pathologically confirmed tumor following TORS, corresponding to the same 8 suspected tumor sites identified with NBI. In contrast, a primary tumor was localized following TORS in 15 of 20 (75%) patients not evaluated with NBI. Thus, we see NBI as a potentially useful tool for the diagnosis and management of p16+ carcinoma of unknown primary.Level of Evidence: IIb.

Principles and practice to facilitate complete photodocumentation of the upper gastrointestinal tract: World Endoscopy Organization position statement

Although esophagogastroduodenoscopy (EGD) is the most commonly used procedure in the gastrointestinal (GI) tract, the method of esophageal, gastric and duodenal mucosa photodocumentation varies considerably worldwide. One probable explanation is that for generations, EGD has primarily been taught by GI faculty and instructors based on their perceptions and experience, which has resulted in EGD being a non-standardized procedure. Currently, the procedure is facing a challenging scenario as endoscopy societies are implementing procedure-associated quality indicators aiming for best practice among practitioners and evidence-based care for patients. Contrary to colonoscopy where cecum landmarks photodocumentation is considered proof of completeness, there are currently no reliable performance measures to gauge the completeness of an upper endoscopy nor guidance for complete photodocumentation. This World Endoscopy Organization (WEO) position statement aims to provide practical guidance to practitioners to carry out complete EGD photodocumentation. Hence, an international group of experts from the WEO Upper GI Cancer Committee formulated the following document using the body of evidence established through literature reviews, expert opinions, and other scientific sources. The group acknowledged that although the procedure should be feasible in any facility, what is needed to achieve a global shift on the concept of completeness is a common written statement of agreement on its potential impact and added value. This best practice statement offers endoscopists principles and practical guidance in order to carry out complete photodocumentation from the hypopharynx to the second duodenal portion.

Follow-up of oral and oropharyngeal cancer using narrow-band imaging and high-definition television with rigid endoscope to obtain an early diagnosis of second primary tumors: a prospective study

Narrow-band imaging (NBI) is an optical technique enhancing mucosal vasculature. The aim of this study is to assess the effectiveness of rigid NBI endoscopy in the early detection of second primaries or local recurrences after treatment for oral (OSCC) and oropharyngeal squamous cell carcinoma (OPSCC), its advantage over standard white-light (WL) endoscopy, and the influence of previous radiotherapy, the learning curve, and lesion site. Between January 2013 and June 2015, 195 patients treated for OSCC or OPSCC with surgery alone (group A) or radiotherapy with or without surgery and/or chemotherapy (group B) underwent additional follow-up assessments using NBI. Sensitivity, specificity, positive/negative predictive values (PPV and NPV), and accuracy for detecting second primaries or local recurrences were calculated for patients with at least two NBI assessments. The effect of previous radiotherapy was determined by test of proportions and that of the learning curve and lesion site with Fisher's exact test. 138/195 patients were included in the analysis. NBI sensitivity, specificity, PPV, NPV, and accuracy for groups A and B were 89.5 vs 100%, 85.2 vs 81.5%, 65.4 vs 69.7%, 96.3 vs 100%, and 86.3 vs 87%, respectively. The diagnostic gain of NBI was 88.2% in group A and 69.6% in group B. The learning curve was the main source of false positives (p = 0.025), whereas radiotherapy and lesion site were uninfluential (p = NS). NBI appears useful for follow-up after treatment for OSCC or OPSCC, its performance being affected only by the learning curve and not by previous treatment or lesion site.

The feasibility of NBI in patients with suspected upper airway lesions: A multicenter study

OBJECTIVE

Narrow band imaging (NBI) improves diagnosis of laryngopharyngeal cancer, but most reported NBI studies are from experienced centers. Feasibility reports on use at everyday outpatient departments are needed.

STUDY DESIGN

Researcher-initiated, prospective, multicenter.

METHODS

Participating physicians were instructed in NBI technique during a 4-hour meeting. Patients underwent an examination that included endoscopy with white light (WL) high-definition (HD) TV and NBI filter in the selected time period. All suspicious lesions were biopsied. The medical records of patients with NBI negative findings were evaluated 6 months after the visit to detect all possible malignant lesions coming into view at mucosal sites. These were considered as false-negative cases, enabling long-term assess to the positive predictive value (NPV) of the protocol.

RESULTS

We enrolled 125 patients. Of those, 84 (67.2%) were males and the median age was 65 years (range, 35-91). In analysis of the accuracy of WL HD TV and NBI against biopsy, the sensitivity and specificity of WL HD TV were 62% and 81%, respectively; and the sensitivity and specificity of NBI were 100% and 84%, respectively. The diagnostic accuracy of NBI was significantly better (P < 0.05). When analyzing medical records 6 months after the initial examination, we found three patients who had been diagnosed with a malignant lesion (NPV of NBI of 96.8%).

CONCLUSION

Narrow band imaging is readily implemented in an everyday outpatient practice, and there seems to be better detection rates of dysplastic/carcinoma lesions with HD NBI compared to HD WL.

LEVEL OF EVIDENCE

2b. Laryngoscope, 127:1821-1825, 2017.

Role of Narrow Band Imaging in Relation to Stroboscopy and White Light Laryngoscopy in Diagnosis of Benign Nonvascular Glottic Lesions

Objective

To evaluate the role of narrow band imaging (NBI) in detecting benign nonvascular glottic lesions.

Materials and methods

Our study is a retrospective and prospective analysis of 247 patients with suspected benign glottic lesions who presented to our voice clinic over a 6-month duration. Patients were diagnosed on stroboscopy (by the first author) and divided into three groups consisting of leukoplakia, sulci, and cysts. A white light (WL) laryngoscopy and NBI examination was performed by an independent laryngologist (not an author) followed by a comparative analysis. The final gold standard for diagnosis was microlaryngoscopy with or without histopathology. Sensitivity of each modality for diagnosis of the three groups was calculated.

Results

The NBI is more sensitive for diagnosing leukoplakia. Stroboscopy is more sensitive for diagnosing sulcus.

Conclusion

Small vocal fold lesions may be missed on WL laryngoscopy. Stroboscopy helps in the diagnosis of structural glottic lesions affecting mucosal wave pattern. Many studies have shown that NBI light highlights the vasculature in superficial mucosal and subepithelial layers. This study is an analysis of the value of NBI in detecting relatively avascular glottic lesions, such as leukoplakia, sulci, and cysts.

How to cite this article

Nerurkar NK, Shedge AE, Gupta HK, Arya AA. Role of Narrow Band Imaging in Relation to Stroboscopy and White Light Laryngoscopy in Diagnosis of Benign Nonvascular Glottic Lesions. Int J Phonosurg Laryngol 2017;7(1):1-5.

Narrow band imaging as screening test for early detection of laryngeal cancer: a prospective study

OBJECTIVES

To analyse the specificity and sensibility of narrow band imaging illumination technology in the early detection of laryngeal cancer in the patients' population without previous diagnosis of laryngeal cancer in a screening setting.

DESIGN

Unicentre, prospective study.

SETTING

One tertiary medical centre.

PARTICIPANTS

A total of 158 patients completed all protocol steps.

MAIN OUTCOME MEASURES

Sensitivity, specificity, positive and negative predictive values of narrow band imaging (NBI) in detecting precancerous lesions and early laryngeal cancer.

RESULTS

The blind assessment of NBI patterns concurred in 90% of patients. In identifying laryngeal cancer and its precursor lesions, in-office NBI showed a high sensitivity of 97% (CI, 84.2%-99.9%), specificity of 92.5% (CI, 79.6%-98.4%), PPV of 91.4% (CI, 76.9%-98.2%), NPV of 97.4% (CI, 86.2%-99.9%) and accuracy of 94.5% but intra-operative NBI demonstrated a sensitivity of 97% (CI, 84.2%-99.9%), a slightly higher specificity of 95% (CI, 83.1%-99.4%), PPV of 94.1% (CI, 80.3%-993%), NPV of 97.4% (CI, 86.5%-99.9%) and accuracy of 95.9%. The comparative receiver operating characteristic curves confirmed a slightly higher performance for the intra-operative NBI evaluation without any statistical significance (P = 0.41).

CONCLUSIONS

Our results confirm the high values of sensitivity and specificity of NBI system in detecting pre-neoplastic laryngeal lesions or early laryngeal cancer in a patients' population selected only by means of risk factors exposure and confirmed the potential role of NBI evaluation as in-office screening tool.

Clinicopathologic characteristics and management of minute esophageal lesions diagnosed by narrow-band imaging endoscopy

BACKGROUND AND STUDY AIMS

Magnifying narrow-band imaging (NBI) endoscopy enables the diagnosis of minute esophageal neoplasia. We aimed to evaluate clinicopathological diagnosis of minute esophageal neoplasia by using magnifying NBI endoscopy and biopsy.

PATIENTS AND METHODS

In total, 309 patients (127 men and 182 women) with minute esophageal lesions of intrapapillary capillary loop (IPCL) type IV were enrolled. Of these patients, 249 underwent biopsy for histologic diagnosis and also for treatment. Of the 249 patients, 123 underwent follow-up with endoscopy. We analyzed the clinicopathologic characteristics and prognosis of these lesions after biopsy.

RESULTS

Of the 249 biopsied lesions, we histologically diagnosed 11 as high-grade intraepithelial neoplasia (HGIN), 41 as low-grade intraepithelial neoplasia (LGIN), and 197 as non-neoplasia (Non-N) including inflammation. Six of the 11 HGINs and 11 of the 41 LGINs showed slight elevation. Background coloration was observed in 9 of 11 HGINs, 34 of 41 LGINs, and 33 of 197 Non-Ns. Of the 249 biopsied lesions, 147 were microscopically measurable. The average diameter was 1.4 mm for HGINs and 0.8 mm for LGINs. Of the 123 patients who underwent post-biopsy follow-up, 93 (76 %) showed no lesions at the biopsied sites during the NBI examinations and were suspected to have undergone complete resection by biopsy.

CONCLUSIONS

Biopsy was useful for diagnosis and treatment of minute esophageal lesions, diagnosed as IPCL type IV by magnifying NBI endoscopy.

The diagnostic performance parameters of Narrow Band Imaging: A preclinical and clinical study

OBJECTIVES

The oral carcinoma is a widespread pathology and still presents poor prognosis. Among the available procedures for its early detection, Narrow Band Imaging technique allows to assess potential vascular network abnormalities. The reliability of this technique in the detection of dysplastic and neoplastic oral lesions was evaluated in a preclinical and clinical study.

MATERIALS AND METHODS

In the preclinical study, a chemical oral carcinogen was administered to 50 mice to induct both dysplastic and neoplastic oral lesions. In the clinical study 91 patients, bearing suspicious premalignant and malignant oral lesions, have been included. Images of animals' and patients' lesions were acquired under white and Narrow Band Imaging light prior to biopsy. Two expert raters examined the images and classified lesions, which were eventually compared to the histological diagnosis. The diagnostic performance included sensitivity, specificity, positive likelihood ratio, positive and negative predictive values, accuracy, percentages and degree of agreement between raters' evaluation and the histological report.

RESULTS

In the preclinical study sensitivity ranged from 0.57 to 1, specificity from 0.85 to 0.99, positive likelihood ratio from 6.54 to 65.04, positive predictive values from 0.32 to 0.96, negative predictive values from 0.91 to 1 and accuracy from 0.86 to 0.98. In the clinical study sensitivity ranged from 0.63 to 0.99, specificity from 0.89 to 1, positive likelihood ratio from 8.45 to 61.47, positive predictive values from 0.59 to 0.96, negative predictive values from 0.78 to 1 and accuracy from 0.82 to 0.99.

CONCLUSION

Narrow Band Imaging is an accurate technique, which holds a great potential for tumour angiogenesis evaluation and for the subsequent early detection of suspicious premalignant and malignant oral lesions.

The diagnostic value of narrow band imaging in different oral and oropharyngeal subsites

The diagnostic value of narrow band imaging (NBI) in the "optical biopsy" of leukoplakias (LP) and erythroplakias (EP) in different oral cavity (OC) and oropharyngeal (OP) subsites is still to be defined. We evaluated 128 unbiopsied and untreated OC/OP LP and EP by conventional oral examination (COE), white light (WL) endoscopy, and NBI and categorized them as "suspicious" or "innocuous". All lesions were treated by excisional biopsy. True positives were those considered as "suspicious" and with histopathology ranging from mild dysplasia to invasive carcinoma. Epithelia were classified as follows: type 1, keratinized thick stratified (gingiva, hard palate, dorsal tongue); type 2a, non-keratinized thin stratified (floor of mouth, vestibule, ventral tongue, soft palate, palatine tonsils, base of tongue); type 2b, non-keratinized, very thick stratified (retromolar trigon, lateral tongue, labial and buccal mucosa). Histopathology revealed 32 % benign lesions, 13 % mild to moderate dysplasias, 15 % severe dysplasias/carcinoma in situ, 16 % microinvasive, and 23 % invasive carcinomas. The false positive rates were 32 % at COE, 27 % at WL, and 15 % at NBI. The false negative rates were 49, 22, and 11 %, respectively. Diagnositic performance was higher for NBI compared to COE (p < 0.001) and to WL (p = 0.004). Comparison of the diagnostic value of NBI among different OC/OP subsites did not show statistically significant difference. NBI as an "optical biopsy" tool significantly reduces the rates of false positives and false negatives in diagnosis of OC/OP cancer compared with COE and WL. No statistically significant difference was noted in its diagnostic value among different OC/OP subsites.

Narrow band imaging: clinical applications in oral and oropharyngeal cancer

Narrow Band Imaging (NBI) is an endoscopic optical imaging enhancement technology that improves the contrast of mucosal surface texture, and enhances visualisation of mucosal and submucosal vasculature. White light is filtered to emit two 30-nm narrow bands of blue (415 nm) and green light (540 nm) light simultaneously, the former corresponding to the main peak absorption spectrum of haemoglobin, and the latter allowing visualisation of blood vessels in the deeper mucosal and submucosal layers. NBI has been used to better assess oral potentially malignant disorders (OPMD), identify oral and oropharyngeal squamous cell carcinoma (SCC), and to define surgical margins of head and neck malignancies. NBI shows great potential in improving detection rates of OPMD, facilitating better assessment of oral and oropharyngeal SCC, and reducing the risk of recurrence for oral SCC. Although further research is required to better understand and define intrapapillary capillary loop (IPCL) patterns and to relate these with clinical, histopathological and molecular parameters especially for early mucosal changes, there is building evidence to recommend its use as the new gold standard for endoscopic assessment in head and neck oncology.

The potential risk of vessel infiltration and cervical lymph node metastasis in hypopharyngeal superficial squamous cell carcinoma: a retrospective observational study

CONCLUSION

The depth of hypopharyngeal superficial cancer may predict vessel infiltration and potential risk of cervical lymph node metastasis.

OBJECTIVES

To elucidate the histopathological predictors of vessel infiltration and the risk of regional lymph node metastasis in hypopharyngeal superficial cancer.

METHODS

This study included 31 lesions from 30 patients who had undergone transoral en bloc resection in the hospital. Patients with intraepithelial neoplasia or muscular invasion were excluded. Patient characteristics, nodal status, state of vessel infiltration, state of perineural invasion, histopathological parameters, and post-operative cervical lymph node recurrence were retrospectively examined. The histopathological parameters measured were tumor diameter and the following three parameters: tumor thickness, depth from the mucosal surface, and depth from the basement membrane. Correlations between histopathological parameters and state of vessel infiltration were statistically analyzed.

RESULTS

Of the 31 lesions examined, four had vessel infiltration. Three of the four lesions with vessel infiltration had regional lymph node metastasis as well as subsequent lymph node metastasis. Lesions with vessel infiltration were significantly deeper than those without. In contrast, there was no significant difference in lesion diameters. In addition, there was no correlation between the depth and the diameter of the lesion.

Can flat-type brownish microlesions in the orohypopharynx be followed up without biopsy or endoscopic resection?

BACKGROUND

Narrow-band imaging (NBI) is useful for detecting superficial oropharyngeal lesions. However, the diagnostic and treatment guidelines for NBI are not established. The aim of the present study was to evaluate the treatment strategy for these microlesions.

METHODS

From October 2008 to September 2009, 68 flat-type brownish microlesions were observed in the orohypopharynx using NBI. Lesions were examined via magnifying NBI (M-NBI) and followed up without biopsy or endoscopic resection for >12 months. To clarify the characteristics, lesions were compared with the endoscopic characteristics of flat-type lesions diagnosed by biopsy and endoscopic resection as squamous cell carcinoma and high-grade intraepithelial neoplasia.

RESULTS

The average diameter of the 68 lesions was 1.6 mm (range, 0.5-5 mm). At the 1-year follow up, 19 lesions had disappeared. No size increases or morphological changes wereobserved among 49 lesions followed for >1 year. At 2 years, 10 patients had dropped out and 11 lesions had disappeared. No changes were observed among 28 lesions followed for >2 years. Of the flat-type lesions as squamous cell carcinoma and high-grade intraepithelial neoplasia, a distinct border and irregular distribution of atypical vessels were observed in all cases using M-NBI. These findings were observed in two of 68 flat-type brownish microlesions during follow up.

CONCLUSION

Although there is some possibility of squamous cell carcinoma or high-grade intraepithelial neoplasia, flat-type microlesions of ≤5 mm diameter in the orohypopharynx may be followed for up to 2 years without biopsy or endoscopic resection.

Perspectives on narrow-band imaging endoscopy for superficial squamous neoplasms of the orohypopharynx and esophagus

BACKGROUND AND AIM

Narrow-band imaging (NBI) is widely available and over the last decade has been applied as a detection and characterization technique for superficial neoplasms of the aerodigestive tract. The aims of the present study were to systematically review clinical trials of NBI endoscopy and to investigate an upgraded NBI system using a novel endoscope for superficial squamous neoplasms in the orohypopharynx and esophagus.

METHODS

Studies on the diagnostic use of NBI endoscopy for superficial squamous neoplasms in the orohypopharynx and esophagus were retrieved from MEDLINE and PubMed and reviewed. An upgraded NBI system using a novel endoscope was investigated with our clinical cases.

RESULTS

In many clinical trials, NBI endoscopy with or without magnification had high diagnostic value for superficial squamousneoplasms in the orohypopharynx and esophagus. An upgraded NBI system can produce a significantly brighter endoscopic view than conventional endoscopes with high-quality magnified images that could be used to diagnose superficial squamous neoplasms.

CONCLUSIONS

NBI endoscopy with or without magnification has diagnostic utility for superficial squamous neoplasms in the orohypopharynx and esophagus. The upgraded NBI endoscopic system is expected to facilitate the use of NBI and magnifying endoscopic diagnosis.

Surveillance after endoscopic mucosal resection or endoscopic submucosal dissection for esophageal squamous cell carcinoma

The objectives of surveillance after endoscopic mucosal resection (EMR) or endoscopic submucosal dissection (ESD) for esophageal squamous cell carcinoma are: (i) early detection and treatment of recurrence; and (ii) early detection and treatment of metachronous esophageal squamous cell carcinoma and second primary cancers. Protocols for follow up after EMR or ESD for esophageal squamous cell carcinoma should be based on the risks of lymph node metastasis and distant metastasis as assessed on the basis of tumor staging at initial treatment. Early detection of recurrence or metachronous carcinomas often allows curative or less invasive treatment. Particular attention should be paid to the development of metachronous esophageal squamous cell carcinomas and second primary cancers (in particular, head and neck cancer and gastric cancer because of their high incidence).

Utility and stability of transnasal endoscopy for examination of the pharynx - a prospective study and comparison with transoral endoscopy

OBJECTIVE

Transnasal endoscopy may be used to observe the head and neck part readily without excessive reflexes. We aimed to evaluate the utility and stability of transnasal esophagogastroduodenoscopy (TN-EGD) in comparison with transoral EGD (TO-EGD) for observation of the pharynx.

STUDY DESIGN

Prospective study

METHODS

A total of 497 patients received unsedated TN-EGD with a 5.5 mm diameter endoscope or unsedated TO-EGD with endoscopes of 6.5 mm, 7.9 mm and 9.2 mm diameter. The rate of completion of pharyngeal observation and numbers of gag reflexes and cough reflexes were recorded.

RESULTS

TN-EGD was performed in 175 patients and TO-EGD was performed in 322 patients. Pharyngeal observation was completed in 173 patients (98.9%) in the TN-EGD group and 235 patients (73.2%) in the TO-EGD group, a significant difference (p<0.001). The TN-EGD group had a low rate of occurrence of gag reflex (0.57%), in contrast, 28.3% of the TO-EGD group had a gag reflex, a significant difference (p<0.01). Multivariable analyses revealed that the use of TN-EGD was the only predictive factor for completion of pharyngeal observation (p<0.0001).

CONCLUSIONS

TN-EGD is ideally suited to observation of the pharynx by unsedated EGD.

Clinicopathological features of minute pharyngeal lesions diagnosed by narrow-band imaging endoscopy and biopsy

AIM: To evaluate the utility of magnified narrow-band imaging (NBI) endoscopy for diagnosing and treating minute pharyngeal neoplasia.

METHODS: Magnified NBI gastrointestinal examinations were performed by the first author. A magnification hood was attached to the tip of the endoscope for quick focusing. Most of the examinations were performed under sedation. Magnified NBI examinations were performed for all of the pharyngeal lesions that had noticeable brownish areas under unmagnified NBI observation, and an intrapapillary capillary loop (IPCL) classification was made. A total of 93 consecutive pharyngeal lesions were diagnosed as IPCL type IV and were suspected to represent dysplasia. Sixty-two lesions of approximately 1 mm in diameter were biopsied in the clinic, and 17 lesions with larger diameters were resected by endoscopic submucosal dissection (ESD) at the Hiroshima University Hospital. In addition to the histological diagnoses, the lesion diameters were microscopically measured in 45 of the 62 biopsies. Thirty-four of the 62 biopsied patients received endoscopic follow up.

RESULTS: Minute pharyngeal lesions were diagnosed in 93 of approximately 3000 patients receiving magnified NBI examinations at the clinic. Of the 93 patients with IPCL type IV lesions, 80 were men, and 13 were women. Fifty-six were drinkers, and 57 were smokers. Two had esophageal cancer. Twenty-one lesions were located on the posterior hypopharyngeal wall, and 72 lesions were located on the posterior oropharyngeal wall. All 93 lesions were flat and showed similar findings in the magnified and unmagnified NBI examinations. Although almost all of the IPCL type IV lesions showed faint redness when examined under white light, it was difficult to diagnose the lesions using only this technique because the contrast was weaker than that achieved in the NBI examinations. Of the 93 lesions, only 3 had diameters greater than 2.1 mm. Sixty-two lesions of approximately 1 mm were biopsied in the clinic, whereas 17 larger lesions were treated by ESD at the Hiroshima University Hospital. Of the 79 pharyngeal lesions that were biopsied or resected by ESD, 5 were histologically diagnosed as high-grade dysplasia, 39 were diagnosed as low-grade dysplasia, and 39 were determined to be non-dysplastic lesions. There were no cancerous lesions. Histologically, abnormal cell size variations and increased nuclear size were observed in all of the high-grade dysplasia lesions, while the incidence of these findings in the low-grade dysplasia lesions was low. Of the 62 biopsied lesions, 45 were microscopically measurable. The measured diameters ranged from 0.1 to 2.0 mm. The dysplasia ratios increased with the diameters. A follow-up endoscopic examination of the 34 biopsied patients found the rate of complete resection by biopsy to be 79%. The largest lesion in which complete resection was expected was a low-grade dysplasia of 1.9 mm in diameter.

CONCLUSION: Minute pharyngeal lesions suspected to be dysplasia that are identified by NBI magnifying endoscopy should be biopsied to determine the diagnosis and further treatment.

Is it proper to use non-magnified narrow-band imaging for esophageal neoplasia screening? Japanese single-center, prospective study

AIM

Most screening examinations in Japanese general hospitals are carried out by high-definition television-incompatible (non-HD) scopes and non-magnifying endoscopes. We evaluated the narrow-band imaging (NBI) real-time diagnostic yield of esophageal neoplasia in high-risk patients at a general hospital.

METHODS

In a single-center, prospective, non-randomized controlled trial, 117 consecutive screening patients with high risk for esophageal cancer received primary white-light imaging (WLI) followed by NBI and iodine-staining endoscopy (59 by HDTV-compatible [HD] endoscopy and 58 by non-HD endoscopy). The primary aim was to evaluate the diagnostic yield of non-magnified images in diagnosing esophageal neoplasia. The secondary aim was to compare HD endoscopy and non-HD endoscopy in terms of diagnostic performance.

RESULTS

Overall, the sensitivity of NBI for screening of esophageal neoplasia was superior to WLI, and equivalent to iodine staining (92% vs 42%; P < 0.05, 92% vs 100%; ns). The specificity of NBI was equivalent to WLI (89% vs 94%; ns). In HD, NBI sensitivity was equivalent to both iodine staining and WLI (100% vs 75%; ns). In non-HD, NBI sensitivity was equivalent to iodine staining, but WLI sensitivity was significantly inferior to NBI (88% vs 100%; ns, 25% vs 88%; P < 0.05). The NBI specificity was equivalent to WLI not only in HD but also in non-HD (90% vs 96%; ns, 88% vs 93%; ns).

CONCLUSION

In both HD and non-HD endoscopy, NBI is less likely than WLI to miss a lesion. Even with non-HD endoscopy, NBI is suitable for esophageal standard examinations in general hospitals.

Lugol chromo-endoscopy versus narrow band imaging for endoscopic screening of esophageal squamous-cell carcinoma in patients with a history of cured esophageal cancer: a feasibility study

To date, Lugol chromo-endoscopy is the reference technique to detect an esophageal neoplasia in patients with prior esophageal squamous-cell carcinoma (ESCC), but is not easy to perform without general anesthesia, which can limit its use in routine practice. The objective of this study were to compare the accuracy of white light, narrow band imaging (NBI), and Lugol to detect esophageal neoplasia in patients with a history of cured ESCC, in a prospective study. Thirty patients were prospectively included between June 2006 and June 2009. They all had a history of cured ESCC. Esophageal mucosa was examined first using white light, second NBI, and third after Lugol staining. Histology was obtained in all abnormalities detected by white light, NBI, and/or Lugol. Five neoplastic lesions in five different patients were identified at histology, four cancers, and one high-grade dysplasia. NBI and Lugol both detected all esophageal neoplastic lesions, whereas white light detected the four cancers but missed the high-grade dysplasia. In this feasibility study, NBI and Lugol both detected all identified esophageal neoplasia in very high-risk patients of ESCC. This result suggests that NBI could be used instead of Lugol to detect an esophageal neoplasia in patients with high risk of ESCC, but needs to be confirmed in a larger study.

Differences of image enhancement in image-enhanced endoscopy: narrow band imaging versus flexible spectral imaging color enhancement

BACKGROUND

Narrow band imaging (NBI) can emphasize images of the surface microvasculature of lesions, because the central wavelengths of the NBI filter are 415 and 540 nm and these wavelengths are well absorbed by hemoglobin. Flexible spectral imaging color enhancement (FICE) increases the contrast in depictions of mucosal lesions. However, quantitative evaluation of the image enhancement shown by NBI and FICE has not been reported. The aim of this study was to measure and compare the degrees of image enhancement in NBI and FICE.

METHODS

We compared the visibility of human blood diluted with distilled water between that shown by white-light imaging (WLI) and that shown by NBI or FICE. One milliliter of human blood was plated onto a 12-well transparent plastic plate to set up doubling dilutions, from 1/2 to 1/2(23). High-definition endoscopes were used for each imaging method. A total of 11 endoscopists independently evaluated the visibility of the diluted blood. The median dilution was defined as the limit of visibility in each image.

RESULTS

NBI enabled clearer visualization of the presence of blood compared with conventional WLI. NBI recognized blood contamination up to a 1/2(14) dilution, whereas conventional WLI recognized blood contamination up to a 1/2(11) dilution. In contrast, FICE did not improve the visualization of diluted blood and recognized blood contamination up to a 1/2(10) dilution.

CONCLUSIONS

NBI more effectively enhanced images of diluted blood compared to conventional WLI, while FICE did not improve the visualization of the diluted blood. These data suggest the usefulness of NBI for the early detection of gastrointestinal neoplasia, which is accompanied by abundant neovascularization.

Nasopharyngeal carcinoma detected by narrow-band imaging endoscopy

The aim of the study was to investigate the novel endoscopic findings in nasopharyngeal carcinoma (NPC) under narrow-band imaging (NBI) and to determine the reliability of screening NPC by NBI. A total of 79 adults underwent nasopharyngeal biopsy. We proposed five distinctly different findings that need to be examined by NBI: Type I: brownish spots, Type II: irregular microvascular pattern (IMVP), Type III: light crests, Type IV: side-difference, Type V: presence of either IMVP or side-difference, of which last three (Type III-V) were a new concept. The results of NPC diagnosis by detecting NBI Type V pattern, the false positive, false negative, sensitivity, specificity, positive predictive value, negative predictive value and accuracy were 6.7%, 2.9%, 97.1%, 93.3%, 91.7%, 97.7%, and 94.9%, respectively. On the other hand, there was a higher prevalence of Type I and IV patterns in T1 category NPC. The nasopharyngeal endoscopy coupled with NBI was able to provide a rapid, convenient, and highly reliable screening for high-risk populations.

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.

Observation of the esophagus, pharynx and lingual root by gastrointestinal endoscopy with a percutaneous retrograde approach

AIM: To evaluate the efficacy of retrograde observation of the esophagus, pharynx, larynx and lingual root.

METHODS: With the beagle dog under anesthesia, the anterior wall of the stomach was fixed on the abdominal wall in a similar way to percutaneous endoscopic gastrostomy. The gastrointestinal scope was inserted via a 12 mm laparoscopic port for subsequent retrograde observation from stomach to the oral cavity.

RESULTS: With this technique, direct observation of gastric cardia was possible without restriction. The cervical esophagus was dilated well, also allowing clear observation of the hypopharyngo-esophageal junction. If the tongue was manually pulled out forward, observation of the lingual root was possible.

CONCLUSION: This procedure is easy and effective for pre-treatment evaluation of the feasibility of endoscopic resection in cases of superficial carcinoma of head and neck.

A useful procedure for observing the cervical esophagus via the hypopharynx

OBJECTIVE

The aim of the study was to evaluate upper gastrointestinal endoscopy with movable over tube (i.e., the movable over tube method) for observing the hypopharynx to cervical esophagus, for use in treatment, and to determine its safety.

METHODS

The study population consisted of 28 patients (23 men, 5 women; a mean age of 66.6 years old; age range of 50-80 years old). The patients consisted of nine cases of globus sensation, eight cases of hypopharyngeal cancer (post-chemoradiotherapy), three cases of hypopharyngeal cancer (untreated), two cases of hoarseness, two cases of unknown primary carcinoma, two cases of foreign body, one case of esophageal cancer, and one case of dysphagia. We used upper gastrointestinal endoscopy with movable over tube to examine the hypopharynx to the cervical esophagus in subjects.

RESULTS

With the movable over tube method, which was performed under pharyngeal surface anesthesia and an infusion of diazepam (5-10mg/kg body weight), one could observe from the hypopharynx to cervical esophagus without any blind spots. There were no complications after the examination.

CONCLUSIONS

The results suggest that the movable over tube method is an easy, useful, and safe method to observe the region from the hypopharynx to the cervical esophagus.

Role of narrow-band imaging and high-definition television in the surveillance of head and neck squamous cell cancer after chemo- and/or radiotherapy

Narrow-band imaging (NBI) is an endoscopic technique enhancing mucosal vasculature and better identifying superficial carcinomas due to their neo-angiogenic pattern. NBI accuracy is increased by combination with a high-definition television (HDTV) camera. The aim of this report was to evaluate the diagnostic improvement of NBI +/- HDTV in the evaluation of head and neck squamous cell cancer (HNSCC) previously treated by chemo-radiotherapy (CHT-RT) or RT. A total of 390 patients affected by HNSCC were prospectively evaluated by NBI and white light (WL) endoscopy +/- HDTV between April 2007 and April 2009 at a single academic institution. Among them, we focused on 59 (15%) patients who received CHT-RT or RT as part of their treatment. Of 59 patients, 13 (22%) showed adjunctive preoperative NBI findings when compared to the standard WL examination. These findings were always confirmed by intraoperative HDTV NBI, while only eight (62%) were visible with HDTV WL. Of 13 lesions, 12 received histopathologic confirmation (from carcinoma in situ to invasive carcinoma). The sensitivity of flexible NBI, HDTV WL, and HDTV NBI was 100, 66 and 100%, respectively. The specificity was 98, 100, and 98%. The positive predictive value was 92, 100, and 92%. The negative predictive value was 100, 94, and 100%. The accuracy was 98, 91, and 98%. NBI +/- HDTV after CHT-RT or RT was of value in detecting tumor persistence (n = 2), early recurrences (n = 6), and metachronous tumors (n = 4). By contrast, only 1 of 59 (2%) patients was found to be false positive.