Narrow band imaging is a new technique in visualization of recurrent respiratory papillomatosis

Usefulness of Intraoperative Narrow-Band Imaging in the Site Diagnosis of Respiratory Papillomatosis

OBJECTIVE

Narrow-band imaging (NBI) is considered useful for detecting respiratory papillomatosis. However, the choice between preoperative and intraoperative NBI depends on the facility. We investigated the usefulness of NBI and determined whether preoperative NBI can replace intraoperative NBI with a comparable detection rate.

METHODS

In this retrospective cohort study conducted at single a tertiary care center, patients with respiratory papillomatosis treated between 2017 and 2022 were enrolled. We systematically compared preoperative white light imaging (WLI) with preoperative and intraoperative NBI. The primary endpoints were the papilloma detection rate and lesion site assessed by the Derkay scoring system. The secondary endpoints were the risk factors for increased Derkay scores.

RESULTS

The study included 127 patients with papilloma. Intraoperative NBI yielded significantly higher Derkay scores than preoperative WLI (p < 0.001) and preoperative NBI (p = 0.004). The papilloma detection rates of preoperative WLI and preoperative NBI were not significantly different. Intraoperative NBI detected more lesions than preoperative NBI in 37 of 127 (29%) patients; the overall number of additional lesions was 47 of 279 (17%). Compared with preoperative NBI, intraoperative NBI yielded significantly higher scores for the vocal cords (p = 0.005), false vocal cords (p = 0.010), and ventricle of the larynx (p < 0.001). Elevated Derkay scores were significantly associated with male sex (p = 0.012) and alcohol consumption (p = 0.007).

CONCLUSION

Intraoperative NBI is more accurate in detecting papillomatous lesions, and preoperative NBI cannot replace intraoperative NBI.

LEVEL OF EVIDENCE

4 Laryngoscope, 134:1820-1824, 2024.

Application of haemoglobin absorption spectral imaging in laryngeal papilloma surgery

OBJECTIVE

This study compares the detection rates of haemoglobin absorption spectral imaging and white light imaging in laryngeal papilloma surgery.

METHODS

Seventeen patients with laryngeal papilloma who underwent surgery in our department from September 2019 to September 2021 were selected. All patients underwent carbon dioxide laser surgery under a microscope. The lesion sites were explored in white light mode and haemoglobin absorption spectral imaging mode. The pharynx and larynx anatomical sites were evaluated using Derkay's all-position scoring system. The numbers and scores for lesions observed in the two modes were compared.

RESULTS

In 17 cases, there were statistically significant differences in the numbers of laryngeal papillomas (Derkay score) detected by white light mode and haemoglobin absorption spectral imaging mode. In 9 of 17 patients (52.94 per cent), the haemoglobin absorption spectral imaging mode showed additional diseased tissues.

CONCLUSION

The haemoglobin absorption spectral imaging mode can dynamically identify diseased tissues in carbon dioxide laser surgery under a microscope and improve the laryngeal papilloma detection rate.

NBI and Laryngeal Papillomatosis: A Diagnostic Challenge: A Systematic Review

Highlights

Abstract

Narrow-band imaging (NBI) represents a valid aid in laryngeal squamous cell carcinoma (LSCC) diagnosis for detecting vascular changes. However, LSCC and laryngeal papillomatosis (LP) show similar vascular patterns that may lead to misdiagnosis and improper treatment. This review aims to deepen this NBI limit in order to stress a careful preoperative evaluation of laryngeal lesions. The research was carried out on PubMed, Web of Science and Scopus databases using specific keywords. The topic of research was assessed by these parameters: accuracy, sensitivity, specificity, and positive and negative predictive values. This review included only five articles: they demonstrated that NBI is better than white-light endoscopy in detecting LSCC and LP. They also reported that LP is frequently mistaken for LSCC, resulting in high rates of false positives using NBI. This is the first review that emphasized this NBI limitation in distinguishing between LP and LSCC in cases of a type V pattern of intraepithelial papillary capillary loop. Although NBI application increased the rate of early cancer detection, LP reduces NBI accuracy. This drawback may lead to misdiagnosis and improper treatment. Our advice is to be careful in cases of type V pattern on NBI and to research LP epithelial and clinical features because it could be a pitfall.

The Narrow Band Imaging as an essential complement to White Light Endoscopy in Recurrent Respiratory Papillomatosis diagnostics and follow-up process

The aim of the study is to discuss the role of NBI imaging in upper respiratory papillomatosis (RRP). In the available literature on the subject, as of 2009, there have been 117 publications on NBI imaging focusing on the diagnosis of the upper respiratory and digestive tract, especially the larynx. They discuss the following diagnostic and therapeutic problems: identifying an abnormal vascular pattern within the mucosa, differentiating benign and malignant lesions, assessing the nature of lesions under the leukoplakia plaque, pre-operative definition of laryngeal cancer margins, supporting laser procedures to obtain safe margins, postoperative monitoring after cancer treatment, detecting second simultaneous and metachronic neoplasms and primary tumors in the case of metastases from an unknown primary site. Few reports have been devoted to the assessment of the extent and recurrence of RRP. Due to its recurrent nature, this pathology deserves special attention as it requires multiple inspections and manipulation within the larynx. It also applies to the pediatric population, where there should be no margin for underestimating or overestimating changes, because any suspicion of recurrence results in subsequent general anesthesia. Hence the attempt to define an unambiguous picture of RRP recurrence and the criteria for referring for subsequent surgical treatment.

Identifying epithelial borders in cholesteatoma surgery using narrow band imaging

Purpose

To quantify changes in the perceived epithelial border with narrow band imaging (NBI) and white light imaging (WLI) during cholesteatoma surgery and to objectify possible benefits of NBI in otology.

Methods

Perioperative digital endoscopic images were captured during combined approach tympanoplasty at our tertiary referral center using WLI and NBI (415 nm and 540 nm wavelengths). Sixteen otologic surgeon defined the epithelial borders within 16 identical WLI and NBI photos. Pixels of these selections were calculated to analyze the quantitative difference between WLI and NBI. A questionnaire also analyzed the qualitative differences.

Results

Sixteen otologic surgeons participated in the study. Stratified per photo, only two photos yielded a significant difference: less pixels were selected with NBI than WLI. A Bland–Altman plot showed no systemic error. Stratified per otologist, four participants selected significantly more pixels with WLI than with NBI. Overall, no significant difference between selected pixels was found. Sub-analyses of surgeons with more than 5 years of experience yielded no additional findings. Despite these results, 60% believed NBI could be advantageous in defining epithelial borders, of which 83% believed NBI could reduce the risk of residual disease.

Conclusion

There was no objective difference in the identification of epithelial borders with NBI compared to WLI in cholesteatoma surgery. Therefore, we do not expect the use of NBI to evidently decrease the risk of residual cholesteatoma. However, subjective assessment does suggest a possible benefit of lighting techniques in otology.

Level of evidence

3.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00405-021-07045-4.

Validation of the European Laryngological Society classification of glottic vascular changes as seen by narrow band imaging in the optical biopsy setting

Purpose

In 2016, the European Laryngological Society (ELS) proposed a classification for vascular changes occurring in glottic lesions as visible by narrow band imaging (NBI), based on the dichotomic distinction between longitudinal vessels (not suspicious) and perpendicular ones (suspicious). The aim of our study was to validate this classification assessing the interobserver agreement and diagnostic test performance in detecting the final histopathology.

Methods

A retrospective study was carried out by reviewing clinical charts, preoperative videos, and final pathologic diagnosis of patients submitted to transoral microsurgery for laryngeal lesions in two Italian referral centers. In each institution, two physicians, independently re-assessed each case applying the ELS classification.

Results

The cohort was composed of 707 patients. The pathologic report showed benign lesions in 208 (29.5%) cases, papillomatosis in 34 (4.8%), squamous intraepithelial neoplasia (SIN) up to carcinoma in situ in 200 (28.2%), and squamous cell carcinoma (SCC) in 265 (37.5%). The interobserver agreement was extremely high in both institutions (k = 0.954, p < 0.001 and k = 0.880, p < 0.001). Considering the diagnostic performance for identification of at least SIN or SCC, the sensitivity was 0.804 and 0.902, the specificity 0.793 and 0.581, the positive predictive value 0.882 and 0.564, and the negative predictive value 0.678 and 0.908, respectively.

Conclusion

The ELS classification for NBI vascular changes of glottic lesions is a highly reliable tool whose systematic use allows a better diagnostic evaluation of suspicious laryngeal lesions, reliably distinguishing benign ones from those with a diagnosis of papillomatosis, SIN or SCC, thus paving the way towards confirmation of the optical biopsy concept.

Juvenile recurrent respiratory papillomatosis treated with combined erlotinib and celecoxib: Initial report

Recurrent respiratory papillomatosis (RRP) is a chronic disease caused by human papillomavirus (HPV). RRP is a clinical challenge because of the high recurrence rate, poor surgery response, extension to tracheobronchial tree and because of the risk of malignancy in some cases. There is no consensus on which adjuvant therapy is better for those patients with highly recurrent course. Because papilloma cells overexpress the epidermal growth factor receptor (EGFR), together with an increased expression of COX-2 and prostaglandin E2, the combination of erlotinib and celecoxib seems plausible, and could be proposed for patients with poor response to previous lines of treatment.

Clinical experience of narrow band imaging (NBI) usage in diagnosis of laryngeal lesions

INTRODUCTION

One of the most recent methods used in imaging of the larynx is narrow band imaging (NBI). NBI enables us to detect specific patterns of pathological angiogenesis suggestive of premalignant or neoplastic lesions. The aim of the study was to compare imaging of laryngeal lesions in white light endoscopy (WLE) and NBI in relation to histopathological examination.

MATERIAL AND METHODS

333 patients with laryngeal lesions underwent endoscopic evaluation in WLE and NBI. Sensitivity, specificity, positive and negative predictive value (PPV, NPV) for WLE and NBI were calculated. The diagnostic value for WLE and NBI was evaluated for two assumptions (positive result is:1. severe dysplasia and cancer 2. only cancer) Results: Sensitivity, specificity, PPV, NPV of first assumption were respectively for white light compared to NBI: 95.4% vs 98.5%; 84.2% vs 98.5%; 79.6% vs 97.7% and 96.6% vs 99.0%. The values of second assumption were: 97.4% vs 100%; 79.3% vs 93.5%; 72.6% vs. 89.4% and 98.2% vs. 100.0%. Higher sensitivity was observed for the second assumption, while higher specifity was recorded for the first assumption. Specificity was significantly higher for NBI than for WLE (p&lt;0.001).

CONCLUSIONS

NBI enables us to detect and differentiate laryngeal lesions, which are invisible in WLE. Endoscopic examination, especially in NBI-mode, is non-invasive, repeatable and remains a useful tool in the daily practice and diagnosis of patients with pathological lesions in the larynx.

High Radiofrequency Surgery and Chromoendoscopy: A Novel Surgical Technique for the Treatment of Respiratory Papillomatosis

Recurrent Respiratory Papillomatosis is a highly recurrent and residual disease. The use of indigo-carmine chromoendoscopy increases the early detection of nonvisible disease and reduces the possibility of leaving residual lesions. The best chances of papillomatosis being eradicated depend upon a surgical shallow epitheliolysis approach applied to patients who have never been surgically damaged before. We developed a novel surgical technique based upon the use of a time controlled High Radiofrequency (HRF) energy output. We applied a three-step bloodless HRF-surgical technique, that is, epitheliolysis, angiolysis and peeling without the aid of adjunct therapies. It acts according to differences in the water density of the tissues. We use it to remove the epithelial viral reservoir thus preserving subepithelial layers. For this purpose, we designed and manufactured a custom-made HRF electrodes set for office and O.R. use. From 2005 to 2018, 39 patients (100%) with recurrent respiratory papillomatosis participated in the present prospective work. Twenty-five (64,10%) achieved complete postsurgical remission, 6 (15,38%) were lost to follow up, and 8 (20,51%) present partial remissions. Thirty-six patients had laryngeal papillomatosis. Follow-up was possible in 30 of the 36 patients with laryngeal papillomatosis with a success remission rate of 83,33% (25 of 30). Eleven of those 36 (30,55%) entered this study without previous surgical treatment and 9 of 11 (81,81%) were cured. Indigo-carmine chromoendoscopy, a visualization solution for papillomatosis detection, together with a bloodless HRF-surgical technique proved to be effective tools to eradicate papillomatosis. Voice restoration to normal or near normal levels was achieved in all patients.

Evaluation of Vascular Patterns Using Contact Endoscopy and Narrow-Band Imaging (CE-NBI) for the Diagnosis of Vocal Fold Malignancy

The endoscopic detection of perpendicular vascular changes (PVC) of the vocal folds has been associated with vocal fold cancer, dysplastic lesions, and papillomatosis, according to a classification proposed by the European Laryngological Society (ELS). The combination of contact endoscopy with narrow-band imaging (NBI-CE) allows intraoperatively a highly contrasted, real-time visualization of vascular changes of the vocal folds. Aim of the present study was to determine the association of PVC to specific histological diagnoses, the level of interobserver agreement in the detection of PVC, and their diagnostic effectiveness in diagnosing laryngeal malignancy. The evaluation of our data confirmed the association of PVC to vocal fold cancer, dysplastic lesions, and papillomatosis. The level of agreement between the observers in the identification of PVC was moderate for the less-experienced observers and almost perfect for the experienced observers. The identification of PVC during NBI-CE proved to be a valuable indicator for diagnosing malignant and premalignant lesions.

Role of narrow band imaging in the diagnosis of laryngeal lesions: Pilot study from India

INTRODUCTION

Narrow band imaging (NBI) is a new imaging technique developed to improve the diagnostic accuracy of head and neck cancers by depiction of tumor-specific neo-angiogenesis. The purpose of this study was to assess the value of NBI in the diagnosis of laryngeal lesions.

AIM

To assess the sensitivity and specificity of combined white light endoscopy (WLE) and NBI compared with WLE alone in the diagnosis of laryngeal lesions.

SETTINGS AND DESIGN

Prospective study.

MATERIALS AND METHODS

Thirty consecutive patients with various laryngeal lesions scheduled for microlaryngoscopic evaluation underwent WLE followed by NBI. Endoscopic NBI findings were classified into five types (I-V) according to the intraepithelial papillary capillary loop features. Types I-IV are considered benign, whereas type V is considered malignant. The observations were compared with histopathology.

STATISTICAL ANALYSIS

Sensitivity, specificity, and positive and negative predictive values for the diagnosis of malignancy (i.e., invasive carcinoma and carcinoma in situ) by means of NBI with WLE were calculated.

RESULTS

The sensitivity of WLE combined with NBI (100%) was higher than WLE alone (82.6%) in detecting laryngeal cancers. NBI helped in identifying four malignant lesions missed by WLE alone. Two children with respiratory papillomatosis also demonstrated type V pattern, a potential pitfall, leading to an overall positive predictive value of 92% and a negative predictive value of 100%.

CONCLUSION

Combining NBI with WLE increases the sensitivity of detection of laryngeal cancer and its precursor lesions. NBI is also useful in some benign lesions as well as in post-radiotherapy patients.

Flexible transnasal endoscopy with white light or narrow band imaging for the diagnosis of laryngeal malignancy: diagnostic value, observer variability and influence of previous laryngeal surgery

Purpose

Flexible transnasal endoscopy is a common examination technique for the evaluation of laryngeal lesions, while the use of narrow band imaging (NBI) has been reported to enhance the diagnostic value of white light endoscopy (WLE). The purpose of this study is to assess observer variability and diagnostic value of both modalities and investigate the possible influence of previous laryngeal surgery on the detection rates of laryngeal malignancy.

Methods

The study was based on the retrospective evaluation of 170 WLE and NBI images of laryngeal lesions by three observers in a random order. The histopathological diagnoses serve as the gold standard.

Results

In identifying laryngeal malignancy, the sensitivity of NBI proved to be higher than that of WLE (93.3% vs. 77.0%). NBI was also superior to WLE in terms of accuracy (96.3% vs. 92%) and diagnostic odds ratio (501.83 vs. 120.65). Both modalities had a specificity of 97.3%. The inter-observer agreement was substantial (kappa = 0.661) for WLE and almost perfect (kappa = 0.849) for NBI. Both WLE and NBI showed a high level of intra-observer agreement. The sensitivity was significantly lower in images with history of previous laryngeal surgery compared to those without.

Conclusions

Flexible transnasal endoscopy has been proved to be a valuable tool in the diagnosis of laryngeal malignancy. The use of NBI can increase the sensitivity and observer reliability in that context and can also provide a diagnostic gain in cases with previous laryngeal surgery

Clinical and surgical implications of intraoperative optical coherence tomography imaging for benign pediatric vocal fold lesions

INTRODUCTION

Benign vocal disorders in children include an extensive list of abnormalities creating a variety of debilitating levels of dysphonia. Precise delineation of the benign lesion type and margins may have significant public health implications in children. An innovative technology such as optical coherence tomography (OCT) is being explored to delineate pediatric benign laryngeal lesions. An accurate assessment of the subepithelial morphology may help towards tailoring more personalized therapeutic treatments. This study was established to highlight key morphological and optical features of benign pediatric laryngeal lesions using intraoperative OCT and to suggest clinical implications that arise from such optical imaging.

METHODS AND MATERIALS

This in vivo study was performed at Massachusetts Eye and Ear Infirmary. Intraoperative imaging was performed on twenty-five pediatric patients ranging from 1 year to 16 years of age presenting hoarseness. Three-dimensional OCT images of benign laryngeal lesions or a subsite of the lesion were acquired.

RESULTS

High-resolution OCT images of 25 patients with benign laryngeal lesions such as nodules, cysts, Reinke's edema, vocalis sulcus, and papilloma revealed distinct and specific morphological differences with normal tissue. Nodules show a symmetrical superficial remodeling of the vocal fold epithelial layer and the basement membrane. Cysts have oval-like shape and are either superficial or deeply located in the lamina propria. Sulcus vocalis OCT imaging allows characterizing if the lesion is shallow or deep according to Ford's classification system. Reinke's edema of the mucosa can be observed and quantified, which may lead to suspicion on the underlying social and medical conditions. Finally, the ability to assess margins and depth of invasion of papilloma lesions is demonstrated, raising the possibility to use OCT with angiolytic lasers for patient-tailored treatments.

CONCLUSIONS

OCT imaging of benign pediatric vocal lesions is promising as it could improve preoperative decision-making and possibly peroperative imaging-guidance for patient-tailored treatments. An assessment of the optical contrast between healthy and abnormal tissue may help towards a more qualitative and quantitative approach to current standard care, especially when diagnosis remains unclear.

The usefulness of narrow band imaging in the assessment of laryngeal papillomatosis

OBJECTIVES/HYPOTHESIS

Recurrent respiratory papillomatosis (RRP) is a benign disease caused by human papillomavirus 6 and 11. The characteristic feature of this disease are wart-like lesions covering the respiratory epithelium with a predilection for the larynx. There is no curative treatment for the disease. The goal of the treatment is a total surgical removal of the papillomatous lesions in order to reduce the number of relapses. Therefore, a good visualization method of papillomas is crucial during surgery. The aim of the study was to compare the accuracy of narrow band imaging (NBI) to the use of white light alone in detecting RRP.

METHODS

The study was carried out between April 2013 and November 2015 at Poznan University of Medical Sciences, Department of Otolaryngology, Poland. Rigid endoscopy with conventional white light (WL) and NBI (CV-260SL processor and CLV- 260SL light source, Olympus Optical Co. Ltd, Tokyo, Japan) was performed in all patients during direct laryngoscopy. All anatomical sites of the larynx and trachea were assessed using the Dikkers scale and Derkay total site scoring system with WL and NBI. The consensus was reached as to the number of lesions seen in WL compared to NBI.

RESULTS

During 36 microlaryngoscopies, the number of papillomas detected in the larynx (by Derkay total site score) differed significantly between white light endoscopy and NBI (Wilcoxon test p = 0.000655). In endoscopy with NBI, a mean of 1.3 more papillomas in Derkay total site score was detected in comparison to white light endoscopy NBI showed additional areas of diseased tissue in 15/36 (41.67%) patients.

CONCLUSIONS

NBI as an additional tool during microlaryngoscopy can improve the detection of papillomatous lesions.

Narrow band imaging for head and neck malignancies: Lessons learned from mistakes

BACKGROUND

The accuracy of white light endoscopy in combination with narrow band imaging (WLE + NBI) for diagnosis of squamous cell carcinoma (SCC) does not reach 100%. We evaluated the characteristics of the false-negative and false-positive cases.

METHODS

Five hundred thirty lesions of the upper airways were evaluated. The WLE was followed by NBI examination before performing a biopsy.

RESULTS

The false-negative lesions (7.36%) were represented by submucosal and non-SCC tumors. Among the 25 non-SCC tumors, 72% did not show any suspicious vascular pattern under NBI. The false-positive lesions (6.04%) were mainly represented by postradiotherapy mucosal changes, ulcers, and infections. Regarding papillomas, NBI accuracy reached 95.32%, although cases with dysplasia were difficult to distinguish from SCC.

CONCLUSION

The WLE + NBI improved diagnostic accuracy, but not all lesions were ideally evaluated with current defined patterns. An accurate anamnesis is mandatory, because, in some cases, it may be more relevant than the NBI pattern.

Evaluation of the combined use of narrow band imaging and high-speed imaging to discriminate laryngeal lesions

BACKGROUND AND OBJECTIVE

Laryngeal lesions are usually investigated by microlaryngoscopy, biopsy, and histopathology. This study aimed to evaluate the combined use of Narrow Band Imaging (NBI) and High-Speed Imaging (HSI) in the differentiation of glottic lesions in awake patients.

STUDY DESIGN

Prospective diagnostic study.

MATERIALS AND METHODS

Thirty-six awake patients with 41 glottic lesions were investigated with both NBI and HSI, and the suspected diagnoses were compared to the histopathological results of tissue biopsies taken during subsequent microlaryngoscopies. Of the 41 lesions, 28 were primary lesions and 13 recurrent lesions after previous laryngeal pathologies.

RESULTS

Sensitivity, specificity, positive predictive value, and negative predictive value in the differentiation between benign/premalignant and malignant lesions with both NBI and HSI accounted to 100.0%, 79.4%, 50.0%, and 100.0%. Sensitivities and specificities were 100.0% and 85.7% for HSI alone, and 100.0% and 79.4% for NBI alone. Regarding only primary lesions the results were generally better with sensitivities and specificities of 100% and 81% for NBI, 100% and 84.2% for HSI and 100% and 85.7% for the combination of both methods, respectively.

CONCLUSION

NBI and HSI both seem to be promising adjunct tools in the differentiation of various laryngeal lesions in awake patients with high sensitivities. Specificities, however, were moderate but could be increased when using NBI and HSI in combination in a subgroup of patients with only primary lesions. Although both methods still have limitations they might ameliorate the evaluation of suspicious laryngeal lesions in the future and could possibly spare patients from repeated invasive tissue biopsies. Lasers Surg. Med. 49:609-618, 2017. © 2017 Wiley Periodicals, Inc.

Narrow band imaging improves observer reliability in evaluation of upper aerodigestive tract lesions

OBJECTIVES/HYPOTHESIS

Visualization by endoscopy is essential in the diagnosis of upper aerodigestive tract lesions. Recent studies showed that narrow band imaging (NBI) increases the diagnostic potential of conventional white light imaging (WLI) by highlighting the superficial vessels. The objective of this study was to evaluate whether the use of NBI would influence inter- and intraobserver agreement while making diagnostic decisions using rigid endoscopy of the upper aerodigestive tract.

STUDY DESIGN

Retrospective study.

METHODS

One hundred routinely collected pictures of laryngeal, hypopharyngeal, and oropharyngeal lesions were used. Rigid endoscopies and patient data collection were performed according to standard protocol. Twelve observers, grouped in different levels of experience, assessed all lesions twice with a 2 to 4 week interval. Fleiss and Cohen's kappa (κ) values were calculated to assess inter- and intraobserver agreement.

RESULTS

Overall interobserver agreement increased from κ = 0.34 to κ = 0.40 by adding NBI to WLI (WLI and WLI + NBI, respectively). In experienced observers, an improvement from κ = 0.39 to κ = 0.43 was observed; in less-experienced observers an improvement from κ = 0.30 to κ = 0.37 was observed. Overall intraobserver agreement increased from moderate (κ = 0.54) to substantial (κ = 0.63) with addition of NBI. Intraobserver agreement for less-experienced observers improved remarkably when WLI was combined with NBI (κ = 0.51 vs. κ = 0.67).

CONCLUSIONS

Addition of NBI during rigid endoscopies of the upper aerodigestive tract led to improvement of both inter- and intraobserver agreement.

LEVEL OF EVIDENCE

4 Laryngoscope, 126:2276-2281, 2016.

[Narrow band imaging for early diagnosis of epithelial dysplasias and microinvasive tumors in the upper aerodigestive tract]

The various stages of tumor growth are characterized by typical epithelial, vascular, and secondary connective tissue changes. Narrow band imaging (NBI) endoscopy is a minimally invasive imaging technique that presents vascular structures in particular at a higher contrast than white light endoscopy alone. In combination with high-resolution image recording and reproduction (high-definition television, HDTV; ultra-high definition, 4K), progress has been made in otolaryngological differential diagnostics, both pre- and intraoperatively. This progress represents an important step towards a so-called optical biopsy. Flexible endoscopy in combination with NBI allows detailed assessment of areas of the upper aerodigestive tract which are difficult to assess by rigid endoscopy. Papillomas, precancerous, and cancerous lesions are characterized by epithelial and connective tissue changes, as well as by typical perpendicular vascular changes. Systematic use of NBI is recommended in the differential diagnosis of malignant lesions of the upper aerodigestive tract. NBI also convinces by a significant improvement in pre- and intraoperative assessment of superficial resection margins. In particular, the combination of NBI and contact endoscopy (compact endoscopy) permits excellent therapeutic decisions during tumor surgery. Intraoperative determination of resection margins at unprecedented precision is possible. In addition, assessment of the form and extent of the perpendicular vessel loops stimulated by epithelial signaling enables differential diagnostic decisions to be made, approximating our goal of an optical biopsy.

Proposal for a descriptive guideline of vascular changes in lesions of the vocal folds by the committee on endoscopic laryngeal imaging of the European Laryngological Society

In the last decades new endoscopic tools have been developed to improve the diagnostic work-up of vocal fold lesions in addition to normal laryngoscopy, i.e., contact endoscopy, autofluorescence, narrow band imaging and others. Better contrasted and high definition images offer more details of the epithelial and superficial vascular structure of the vocal folds. Following these developments, particular vascular patterns come into focus during laryngoscopy. The present work aims at a systematic pathogenic description of superficial vascular changes of the vocal folds. Additionally, new nomenclature on vascular lesions of the vocal folds will be presented to harmonize the different terms in the literature. Superficial vascular changes can be divided into longitudinal and perpendicular. Unlike longitudinal vascular lesions, e.g., ectasia, meander and change of direction, perpendicular vascular lesions are characterized by different types of vascular loops. They are primarily observed in recurrent respiratory papillomatosis, and in pre-cancerous and cancerous lesions of the vocal folds. These vascular characteristics play a significant role in the differential diagnosis. Among different parameters, e.g., epithelial changes, increase of volume, stiffness of the vocal fold, vascular lesions play an increasing role in the diagnosis of pre- and cancerous lesions.

Narrow Band Imaging

Objectives:

Narrow band imaging (NBI) is supposed to be a technique for a better visualization of vessel structures in superficial tissue as it selects the wavelengths of hemoglobin. It was hypothesized that, in the regular follow-up examination of patients with recurrent laryngeal papillomatosis, NBI enables a better detection of laryngeal papillomatosis in contrast to normal white light endoscopy.

Methods:

Eleven patients, 10 with a known recurrent papillomatosis (8 with a relapse, 2 without) and 1 with a primary diagnosis of papillomatosis, were examined with normal white light and NBI endoscopy. Twenty-six video sequences (11 white, 11 NBI, 4 doubled for validity) were generated and randomly presented to 20 otolaryngologists who rated the videos in terms of lesions seen and number of lesions identified. Results were compared with the histopathologic findings of microlaryngoscopy.

Results:

Detection of papillomatosis and the correct number of lesions identified were more accurate with NBI than with normal white light endoscopy. There was a significantly higher probability of detecting laryngeal papillomata with NBI.

Conclusions:

NBI endoscopy enables a more accurate detection of laryngeal papillomatosis than white light endoscopy.

Multi-color reflectance imaging of middle ear pathology in vivo

Otoscopic examination using white-light illumination has remained virtually unchanged for well over a century. However, the limited contrast of white-light otoscopy constrains the ability to make accurate assessment of middle ear pathology and is subject to significant observer variability. Here, we employ a modified otoscope with multi-color imaging capabilities for superior characterization of the middle ear constituents in vivo and for enhanced diagnosis of acute otitis media and cholesteatoma. In this pilot study, five patients undergoing surgery for tympanostomy tube placement and congenital cholesteatoma excision were imaged using the custom-designed multi-color video-rate reflectance imaging system. We show that the multi-color imaging approach offers an increase in image contrast, thereby enabling clear visualization of the middle ear constituents, especially of the tympanic membrane vascularity. Differential absorption at the multiple wavelengths provides a measure of biochemical and morphological information, and the rapid acquisition and analysis of these images aids in objective evaluation of the middle ear pathology. Our pilot study shows the potential of using label-free narrow-band reflectance imaging to differentiate middle ear pathological conditions from normal middle ear. This technique can aid in obtaining objective and reproducible diagnoses as well as provide assistance in guiding excisional procedures.

The role of NBI HDTV magnifying endoscopy in the prehistologic diagnosis of laryngeal papillomatosis and spinocellular cancer

Narrow band imaging (NBI) HDTV (high definition television) magnifying endoscopy is considered to be superior for the accurate display of the microvascular patterns of superficial mucosal lesions. Observation of changes in intraepithelial papillary capillary loops (IPCL) can help distinguish benign from malignant lesions as part of an "optical biopsy." However, IPCL changes in papillomas may be mistaken for spinocellular cancer (SCC). The aim of the study was to determine whether observing microvascular changes alone is sufficient for discriminating between laryngeal SCC and papillomatosis. An additional aim was to identify associated characteristics that could clarify the diagnosis. The study included 109 patients with a suspected laryngeal tumor or papilloma. HDTV NBI magnifying endoscopy was performed during direct laryngoscopy. It was possible to visualize IPCL changes in 82 out of 109 patients (75.2%). In 71 (86.6%) patients, the diagnosis was correctly determined. In 4 (4.9%) cases, the diagnosis of SCC was expressed on the basis of finding pathologic IPCL, but histology did not demonstrate malignancy. To achieve a correct diagnosis using HDTV NBI magnifying endoscopy, it is important not only to observe changes in the shape of IPCL but also to note possible papillary structures with central-axis capillaries typical of papillomatosis.

The effect of endoscopic sheaths on visualization in distal chip and fiberoptic laryngoscopy

Endoscopic sheaths covering the laryngoscope are advised to prevent cross contamination, but might hamper visualization as the most important tool in the diagnostic approach of laryngeal disease. We evaluated whether endoscopic sheaths change image quality and diagnostic accuracy of flexible distal chip laryngoscopy (DCL) and flexible fiberoptic laryngoscopy (FOL). Twelve healthy volunteers underwent a flexible laryngoscopy using a distal chip and a fiberoptic laryngoscope with and without endoscopic sheaths, and in this way 48 images were collected. To determine diagnostic accuracy, the 48 images were mixed with images of 40 patients. All images were randomly shown to four experts in the field of laryngology and head and neck oncology. Observers were asked to validate image quality, choose a diagnosis, and express their confidence level of that diagnosis. Image quality was validated better in DCL as compared to FOL (p < 0.05) both with or without endoscopic sheaths. Endoscopic sheaths worsened image quality in DCL (p < 0.05) but not in FOL. No differences were observed between DCL and FOL with or without endoscopic sheaths in diagnostic accuracy (79-89%). Confidence levels (7.7-8.1) were comparable in DCL and FOL and not influenced by endoscopic sheaths. Image quality in DCL is superior to FOL, but significantly hampered by the use of endoscopic sheaths. In FOL the image quality is already low and not further diminished by endoscopic sheaths.