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

Value of high-speed videoendoscopy as an auxiliary tool in differentiation of benign and malignant unilateral vocal lesions

PURPOSE

The study aimed to assess the relevance of objective vibratory parameters derived from high-speed videolaryngoscopy (HSV) as a supporting tool, to assist clinicians in establishing the initial diagnosis of benign and malignant glottal organic lesions.

METHODS

The HSV examinations were conducted in 175 subjects: 50 normophonic, 85 subjects with benign vocal fold lesions, and 40 with early glottic cancer; organic lesions were confirmed by histopathologic examination. The parameters, derived from HSV kymography: amplitude, symmetry, and glottal dynamic characteristics, were compared statistically between the groups with the following ROC analysis.

RESULTS

Among 14 calculated parameters, 10 differed significantly between the groups. Four of them, the average resultant amplitude of the involved vocal fold (AmpInvolvedAvg), average amplitude asymmetry for the whole glottis and its middle third part (AmplAsymAvg; AmplAsymAvg_2/3), and absolute average phase difference (AbsPhaseDiffAvg), showed significant differences between benign and malignant lesions. Amplitude values were decreasing, while asymmetry and phase difference values were increasing with the risk of malignancy. In ROC analysis, the highest AUC was observed for AmpAsymAvg (0.719; p < 0.0001), and next in order was AmpInvolvedAvg (0.70; p = 0.0002).

CONCLUSION

The golden standard in the diagnosis of organic lesions of glottis remains clinical examination with videolaryngoscopy, confirmed by histopathological examination. Our results showed that measurements of amplitude, asymmetry, and phase of vibrations in malignant vocal fold masses deteriorate significantly in comparison to benign vocal lesions. High-speed videolaryngoscopy could aid their preliminary differentiation noninvasively before histopathological examination; however, further research on larger groups is needed.

The Effectiveness of White Light Endoscopy Combined With Narrow Band Imaging Technique Using Ni Classification in Detecting Early Laryngeal Carcinoma in 114 Patients: Our Clinical Experience

INTRODUCTION

By displaying tumor-specific neoangiogenesis, narrow band imaging (NBI), a novel imaging approach, enhances the diagnosis of head and neck cancers and makes it more accurate OBJECTIVE: To determine the effect of NBI in combination with white light endoscopy (WLE) for diagnosis of preneoplastic or neoplastic laryngeal cancers according to Ni classification and to conclude if higher Ni classification and tumor stage are related.

METHODS

We enrolled 114 patients with various laryngeal cancer between December 2018 and June 2021. Patients were examined with WLE and NBI. Squamous cell carcinoma (SCC) accounted for 46 cases, benign lesions 30 cases, and nondysplastic, low-grade, and severe dysplasias for 38 cases. Based on characteristics of the intraepithelial papillary capillary loop (IPCL), endoscopic NBI results were divided into five categories (I, II, III, IV, and V). Type I-IV are regarded to be benign, while type V is considered to be cancerous. An incisional biopsy was conducted to assess histopathology, and the histopathology was compared to the NBI results. We assessed the negative predictive value (NPV), positive predictive value (PPV), specificity, and sensitivity for WLE alone and WLE combined with NBI. Analyses were conducted using SPSS software version 26.

RESULTS

The WLE combined with NBI showed excellent sensitivity (96%) compared to WLE (86.4%). Specificity was higher in the WLE combined with NBI (96.4%) than WLE alone (91.7%). WLE combined with NBI saw a NPV of 89% as compared with WLE with 88%. WLE and WLE in combination with NBI, recorded a PPV of 90% and 98%, respectively.

CONCLUSION

The accuracy of detecting laryngeal cancer increases when WLE and NBI are combined. Combined NBI with WLE remains highly sensitive to early glottis cancer. Accuracy of preoperative NBI was high. In the diagnosis of laryngeal cancer, a higher Ni classification closely correlates with the late stages of the glottis tumor.

Evaluation of an image enhancement system for the assessment of nasal and paranasal sinus diseases

PURPOSE

Dysplasia and cancer of the upper aerodigestive tract are characterized by significant neoangiogenesis. This can be recognized by optical methods like the Storz Professional Image Enhancement System (SPIES). Up to now, there are no reports of using this novel technique for examining nasal diseases. The objective of this study was to evaluate the use of SPIES during sinus surgery to help differentiate various nasal pathologies and determine their extension.

METHODS

Patients (n = 27) with different pathologies in the region of the paranasal sinuses were operated via functional endoscopic surgery using a 2D-HD-camera with white light and SPIES. In addition, 10 healthy individuals were examined. The system was evaluated using two different questionnaires.

RESULTS

The handling and operation of SPIES was intuitive and easy. Use of SPIES did not prolong the procedure. There was no disturbing image distortion. SPIES seemed to improve the visualization, differentiation and evaluation of vascularization of paranasal pathologies and allowed for precise and accurate surgery. Compared to examination with the 2D-HD-camera and white light alone, SPIES appeared to facilitate the identification of mucosal pathologies.

CONCLUSION

SPIES could be a promising adjunct tool to evaluate nasal pathologies intraoperatively. Especially in the case of vascularized tumors the enhanced image endoscopy seemed to be clearly superior to standard white light alone. In our study, the system facilitated the assessment of tumor extension and vascularization as well as the differentiation of healthy mucosa. Future randomized studies will be necessary to prove the potential of integrating this novel technique into the clinical routine for the differentiation of nasal pathologies and the improvement of resection margins during nasal tumor surgery.

LPCANet: Classification of Laryngeal Cancer Histopathological Images Using a CNN with Position Attention and Channel Attention Mechanisms

Laryngeal cancer is one of the most common malignant tumors in otolaryngology, and histopathological image analysis is the gold standard for the diagnosis of laryngeal cancer. However, pathologists have high subjectivity in their diagnoses, which makes it easy to miss diagnoses and misdiagnose. In addition, according to a literature search, there is currently no computer-aided diagnosis (CAD) algorithm that has been applied to the classification of histopathological images of laryngeal cancer. Convolutional neural networks (CNNs) are widely used in various other cancer classification tasks. However, the potential global and channel relationships of images may be ignored, which will affect the feature representation ability. Simultaneously, due to the lack of interpretability, the results are often difficult to accept by pathologists. we propose a laryngeal cancer classification network (LPCANet) based on a CNN and attention mechanisms. First, the original histopathological images are sequentially cropped into patches. Then, the patches are input into the basic ResNet50 to extract the local features. Then, a position attention module and a channel attention module are added in parallel to capture the spatial dependency and the channel dependency, respectively. The two modules produce the fusion feature map to enhance the feature representation and improve network classification performance. Moreover, the fusion feature map is extracted and visually analyzed by the grad-weighted class activation map (Grad_CAM) to provide a certain interpretability for the final results. The three-class classification performance of LPCANet is better than those of the five state-of-the-art classifiers (VGG16, ResNet50, InceptionV3, Xception and DenseNet121) on the two original resolutions (534 * 400 and 1067 * 800). On the 534 * 400 data, LPCANet achieved 73.18% accuracy, 74.04% precision, 73.15% recall, 72.9% F1-score, and 0.8826 AUC. On the 1067 * 800 data, LPCANet achieved 83.15% accuracy, 83.5% precision, 83.1% recall, 83.1% F1-score, and 0.9487 AUC. The results show that LPCANet enhances the feature representation by capturing the global and channel relationships and achieves better classification performance. In addition, the visual analysis of Grad_CAM makes the results interpretable, which makes it easier for the results to be accepted by pathologists and allows the method to become a second tool for auxiliary diagnosis.

The Impact of Narrow-band Imaging on the Pre- and Intra- operative Assessments of Neoplastic and Preneoplastic Laryngeal Lesions. A Systematic Review

Introduction  Narrow-band imaging is an endoscopic diagnostic tool that, focusing on superficial vascular changes, is useful to detect suspicious laryngeal lesions, enabling their complete excision with safe and tailored resection margins.

Objectives  To analyze the applications and benefits of narrow-band imaging in detecting premalignant and malignant laryngeal lesions through a comparison with white-light endoscopy.

Data Synthesis  A literature search was performed in the PubMed, Scopus and Web of Science databases using strict keywords. Then, two authors independently analyzed the articles, read the titles and abstracts, and read completely only the relevant studies according to certain eligibility criteria. In total, 14 articles have been included in the present review; the sensitivity, specificity, positive and negative predictive values, and accuracy of pre- and/or intraoperative narrow-band imaging were analyzed. The analysis showed that narrow-band imaging is better than white-light endoscopy in terms of sensitivity, specificity, positive and negative predictive values, and accuracy regarding the ability to identify cancer and/or precancerous laryngeal lesions. Moreover, the intraoperative performance of narrow-band imaging resulted more effective than the in-office performance.

Conclusion  Narrow-band imaging is an effective diagnostic tool to detect premalignant and malignant laryngeal lesions and to define proper resection margins. Moreover, narrow-band imaging is useful in cases of leukoplakia that may cover a possible malignant lesion and that cannot be easily assessed with white-light endoscopy. Finally, a shared, simple and practical classification of laryngeal lesions, such as that of the European Laryngological Society, is required to identify a shared lesion management strategy.

Key Points

Laryngeal Image Processing of Vocal Folds Motion

This review provides a comprehensive compilation, from a digital image processing point of view of the most important techniques currently developed to characterize and quantify the vibration behaviour of the vocal folds, along with a detailed description of the laryngeal image modalities currently used in the clinic. The review presents an overview of the most significant glottal-gap segmentation and facilitative playbacks techniques used in the literature for the mentioned purpose, and shows the drawbacks and challenges that still remain unsolved to develop robust vocal folds vibration function analysis tools based on digital image processing.

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.

Value of pre- and intraoperative diagnostic methods in suspected glottic neoplasia

PURPOSE

To evaluate the individual and combined ability of videostroboscopy (VS), high-speed digital imaging (HSDI), enhanced endoscopy (EE) and saline infusion (SI) to predict neoplasia, defined as glottic precursor lesion (GPL) or T1a glottic cancer, in patients suspected for glottic neoplasia.

METHODS

A nationwide prospective cohort study of patients treated by cordectomy for suspected GPL or T1a glottic cancer from August 1st 2016 to October 31st 2018 was conducted in the five Danish University Departments of Head and Neck surgery. Sensitivity, specificity, negative and positive predictive values, and area under Receiver Operating Curves (AUC-ROC) were calculated with 95% confidence intervals with respect to the histological diagnosis. Logistic regression with an imputation model for missing data was applied.

RESULTS

261 patients aged 34-91 years participated; 79 (30.3%) with non-neoplasia (i.e., inflammation, papilloma, hyperkeratosis) and 182 (69.7%) neoplasia, hereof 95 (36.4%) with GPL and 87 (33.3%) with T1a glottic cancer. Data from 188 VS, 60 HSDI, 100 preoperative EE, 209 intraoperative EE, and 234 SI were analyzed. In the complete case analysis the AUC-ROC of each diagnostic test was low, but increased when the tests were combined and especially if the combination included EE. However, multinomial logistic regression with imputation showed significant association (p < 0.05) only between age, male gender, and perpendicular vasculature in intraoperative EE, and the endpoint neoplasia.

CONCLUSIONS

Intraoperative EE was the most accurate diagnostic method in detecting neoplasia. The prediction ability of methods applied preoperatively was more limited, but improved when test modalities were combined.

The Prognostic Value of Adding Narrow-Band Imaging in Transoral Laser Microsurgery for Early Glottic Cancer: A Review

BACKGROUND AND OBJECTIVES

Transoral laser microsurgery (TLM) is a universally recognized safe and minimally invasive approach for early glottic cancer. Narrow band imaging (NBI) is an optical technique working with a filtered light that reveals superficial mucosal abnormalities through the neoangiogenic pattern. The aim of this systematic review is to demonstrate the role of intraoperative NBI during TLM for early glottic cancer to better evaluate tumor extension and for more precise margin resection.

STUDY DESIGN/MATERIALS AND METHODS

A systematic review of the literature following the PRISMA guidelines was performed. A literature search was performed using the following keywords: TLM, NBI, and early glottic cancer. Two independent authors evaluated the extracted data. Data regarding status of surgical margins after TLM, local recurrence, recurrence-free survival, and need of additional samples following NBI were collected.

RESULTS

Five articles met inclusion criteria with a total of 577 patients undergoing TLM with intraoperative NBI. A significant reduction of positive superficial margins was found in patients treated with (52%) and without (28.6%) intraoperative use of NBI (P < 0.05) CONCLUSIONS: Routine use of intraoperative NBI increases the accuracy of neoplastic superficial spreading evaluation and accuracy of mass resection during TLM for early glottic cancer. The significant reduction of superficial positive margins dramatically decreases the number of patients at risk and improves clinical outcomes. Lasers Surg. Med. © 2019 Wiley Periodicals, Inc.

Computational analysis of six optical coherence tomography systems for vocal fold imaging: A comparison study

OBJECTIVES

There have been many advancements in laryngeal imaging using optical coherence tomography (OCT), with varying system design and probes for use in research, office, and operating room settings. We evaluated the performance of six distinct OCT systems in imaging porcine vocal folds (cords) using computational image processing and segmentation.

METHODS

Porcine vocal folds were scanned using six OCT systems. Imaging system and probe performance were quantitatively assessed for signal penetration, layer differentiation, and epithelium (EP) measurement. Fitted exponential decay curves with corresponding α constant and intensity thresholding segmentation were utilized to quantify the aforementioned parameters.

RESULTS

The smallest average α constant and deepest signal penetration was of the SS-OCT 1700 nm 90 kHz microscope system (α = -1.74), followed by the SS-OCT 1310 nm 200 kHz VCSEL microscope system (α = -1.99), and SS-OCT 1310 nm 50 kHz rigid forward viewing endoscope system (α = -2.23). The EP was not readily visualized for three out of six systems, but was detected using automated segmentation. Average EP thickness (mean ± SD) was calculated as 55.79 ± 31.86 μm which agrees favorably with previous literature.

CONCLUSION

Comparisons of OCT systems are challenging, as they encompass different probe design, optical path, and lasers, depending on application. Practical evaluation of different systems using computer based quantitative image processing and segmentation revealed basic, constructive information, such as EP measurements. To further validate the comparisons of system performance with clinical usability, in vivo human laryngeal imaging will be conducted. Further development of automated image processing and segmentation can be useful in rapid analysis of information. Lasers Surg. Med. 51:412-422, 2019. © 2019 Wiley Periodicals, Inc.

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

Development of three-dimensional laryngostroboscopy for office-based laryngeal diagnostics and phonosurgical therapy

OBJECTIVE

To develop a three-dimensional (3D) laryngostroboscopic examination unit, compare the optic playback quality in relation to established 2D procedures, and report the first case series using 3D rigid laryngostroboscopy for diagnosis and management of laryngotracheal diseases.

STUDY DESIGN

Laboratory study, prospective case series.

METHODS

The optical efficacy of newly developed rigid 3D endoscopes was examined in a laboratory setting. Diagnostic suitability was investigated in 100 subjects (50 male, 50 female) receiving 2D high-definition (HD) and 3D laryngostroboscopy. Two of the subjects subsequently underwent 3D-assisted office-based transoral phonosurgery under local anesthesia. Main outcome measures were comparative visualization of laryngotracheal pathologies, influence on preoperative planning, and evaluation of prognostic factors for the outcome of phonosurgical interventions.

RESULTS

Three-dimensional endostroboscopic procedures were effectively optimized to establish an examination protocol for all-day clinical use. Office-based 3D laryngostroboscopy was successfully applied in subjects with normal anatomy (n = 10) and various laryngotracheal findings (n = 90). In comparison to 2D HD videolaryngostroboscopy, the 3D view offered enhanced visualization of laryngotracheal anatomy, with qualitatively improved depth perception and spatial representation. In organic pathologies, this resulted in a more precise indication of phonosurgical procedures, increased accuracy in surgical planning, facilitated office-based endoscopic surgery, and better evaluation of prognostic factors for the outcome of phonosurgical interventions.

CONCLUSION

Three-dimensional laryngostroboscopy proved to increase the understanding of functional and surgical anatomy. Its application has enormous potential for improving the diagnostic value of laryngoscopy, surgical precision in laryngotracheal interventions, tissue preservation, and methods of teaching.

LEVEL OF EVIDENCE

NA Laryngoscope, 128:2823-2831, 2018.

The value of narrow band imaging combined with stroboscopy for the detection of applanate indiscernible early-stage vocal cord cancer

BACKGROUND

Narrow band imaging (NBI) and stroboscopy are non-invasive techniques to detect the malignant lesions of the vocal cord. This study was to assess the diagnostic value of combined endoscopic analysis in the applanate indiscernible early-stage vocal cord cancer.

METHODS

A total of 110 patients with 160 suspicious vocal cord malignant lesions were included in this retrospective study. Stroboscopy was immediately performed after NBI and white light endoscopy (WLE) were performed in all patients. Excisional biopsy was performed to examine histopathology examination.

RESULTS

We found that the diagnostic specificity and PPV were higher in the NBI and WLE combined with stroboscopy group than in the NBI and WLE group without stroboscopy (88.9% vs 72.5%, 88.4% vs 60.9%). However, the diagnostic sensitivity was not significantly different in those two groups (69.3% vs 67.7%).

CONCLUSION

NBI and WLE combined with stroboscopy is a promising method to detect early-stage vocal cord cancer with the advantage of clinical feasibility and diagnostic specificity.

Primary and salvage laser surgery of 341 glottic cancers-Comparison of treatment outcomes between University Head Neck Tertiary Referral Center and Local Head Neck Department

OBJECTIVE

The main goal was to compare the clinical data of patients with T1 and T2 glottic cancer treated with CO₂ transoral laser microlaryngoscopy (TLM) in the Tertiary Referral University Department of Otolaryngology, Head Neck Surgery, Poznan and the local Department of Otolaryngology, Oncology and Maxillofacial Surgery, Bydgoszcz.

MATERIAL AND METHODS

Unified databases for the 7-year period January 2005-December 2011 were created to compare these two cohorts. The database contained 341 patients: 231 from the tertiary center and 110 from the local department, of which 298 (87%) were men, and 43 (13%) were women.

RESULTS

Cordectomy type I-IV was performed in 250 (73%) patients, cordectomy type V-VI in 84 (25%) patients, and cordectomy enlarged to epiglottic petiole in 7 (2%) patients. Local recurrence was observed in 96 (28%) cases. Among these cases, 81 (87.5%) patients had salvage surgery: 43 re-cordectomy, 10 open partial laryngectomy, and 28 total laryngectomy. The outcomes for the whole cohort, Tertiary Referral Center and Local Department respectively were as follows: larynx preservation rate was 91.8%, 93.6%, and 88%; 3-year disease specific survival was 97.4%, 97.9%, and 93.3%; 3-year overall survival was 93.5%, 96.6%, and 85.5%; 5-year disease specific survival was 95.2%, 95.2%, and 96.3%; and 5-year overall survival was 84.5%, 88.7%, and 76%, respectively.

CONCLUSION

Comparison of the cohorts showed that outcomes of primary treatment were similar but there were noticeable differences in salvage treatment efficacy, favoring patients from the Tertiary Referral Center. Lasers Surg. Med. 50:311-318, 2018. © 2017 Wiley Periodicals, Inc.