Detecting early oral cancer: narrowband imaging system observation of the oral mucosa microvasculature

Recent advances of photodiagnosis and treatment for head and neck squamous cell carcinoma

Head and neck squamous cell carcinoma (HNSCC) are the most common type of head and neck tumor that severely threatens human health due to its highly aggressive nature and susceptibility to distant metastasis. The diagnosis of HNSCC currently relies on biopsy and histopathological examination of suspicious lesions. However, the early mucosal changes are subtle and difficult to detect by conventional oral examination. As for treatment, surgery is still the primary treatment modality. Due to the complex anatomy and the lack of intraoperative modalities to accurately determine the incision margins, surgeons are in a dilemma between extensive tumor removal and improving the quality of patient survival. As more knowledge is gained about HNSCC, the increasing recognition of the value of optical imaging has been emphasized. Optical technology offers distinctive possibilities for early preoperative diagnosis, intraoperative real-time visualization of tumor margins, sentinel lymph node biopsies, phototherapy. Fluorescence imaging, narrow-band imaging, Raman spectroscopy, optical coherence tomography, hyperspectral imaging, and photoacoustic imaging have been reported for imaging HNSCC. This article provides a comprehensive overview of the fundamental principles and clinical applications of optical imaging in the diagnosis and treatment of HNSCC, focusing on identifying its strengths and limitations to facilitate advancements in this field.

Laryngeal Carcinoma Characteristics Associated with Positive Margins and Endoscopic Understaging

Background/Objectives: The study aims to analyse the factors associated with positive margins and endoscopic understaging in laryngeal carcinoma. It also aims to assess the diagnostic accuracy of Narrow Band Imaging (NBI) in comparison to White Light Endoscopy (WLE) and other diagnostic methods. Methods: In this retrospective comparative cohort analysis, 206 patients who underwent endoscopic laser surgery for T1 and T2a glottic squamous cell carcinoma between 1 January 2016 and 30 April 2023 were included. The data were collected from endoscopy, CT, histopathology, and NBI images. Statistical analysis was performed and associations between variables were analysed using binary logistic regression and receiver operating characteristic analysis. Results: The types of cordectomy performed included type III (51 patients), type IV (40 patients), and type VI (23 patients). Positive margins were found in 14.01% of patients, with significant correlations observed between positive margins and bilateral laryngeal carcinoma, right-sided laryngeal carcinoma, higher clinical and histopathologic T categories, and higher NBI grade. Endoscopic understaging versus histopathologic T category correlated with various factors, including cordectomy type, tumour size, and clinical T category. The NBI findings correlated with positive margins but did not correlate with endoscopic understaging. Conclusions: The study highlights several clinical and pathological factors associated with positive margins and endoscopic understaging in laryngeal carcinoma. NBI demonstrated high diagnostic accuracy, correlating with histopathological results and serving as an independent predictive factor for positive margins. Recognizing these factors is crucial for improving preoperative assessments, refining treatment strategies, and enhancing patient care.

Prospects for Narrow Band Imaging Magnification Endoscopy in Oral Lesions: Recommendations from Oral and Maxillofacial Surgeons and a Gastroenterologist

Narrow band imaging (NBI) magnification endoscopy for the diagnosis of early-stage oral cavity-related cancer and precancerous lesions can recognize oral lesions as brownish areas, and can observe intraepithelial papillary capillary loops (IPCLs) in the mucosa and submucosa to make a qualitative diagnosis of the lesion and highlight the mucosal surface microstructure to facilitate appropriate diagnosis and early treatment. IPCLs are classified from Type 0 to IV: Type 0 is normal mucosa or no blood vessels observed, e.g., in keratinization; Type I is mainly normal mucosa; Type II is mainly inflammatory sites or non-malignant lesions; Type III is mainly precancerous or suspected malignant lesions; and Type IV is cancerous or malignant lesions. NBI magnification endoscopy is a useful noninvasive method for identifying the malignant transformation of oral potentially malignant disorders (OPMDs). Oral lesions classified as IPCL Type II or higher are atypical epithelial or oral squamous cell carcinoma (OSCC); oral biopsy is recommended for early and accurate diagnosis, and is an indicator of the appropriate biopsy site in the follow-up for OPMDs. In the future, the accuracy of NBI magnification endoscopy for malignant transformation of OPMDs and OSCC will be further confirmed.

Prognostic Effect of Patterns of Local Extension and Satellitosis in cT3 Squamous Cell Carcinoma of the Oral Tongue: A Prospective Observational Study

INTRODUCTION

The anatomy of the tongue is three-dimensionally complex and is thought to play a central role in the local growth of oral tongue squamous cell carcinoma (OTSCC). Understanding patterns of tumor extension could improve a multimodal therapeutic approach. Thus, the main aim of this study was to provide a histological and microanatomical analysis of surgical specimens after compartmental surgery for OTSCC.

MATERIALS AND METHODS

The present prospective observational study included primary cT3 OTSCC (according to the eighth edition of the TNM classification) treated in an academic tertiary referral center with curative compartmental surgery, from July 2016 to July 2019. Analysis of histologic macrosections allowed assessment of standard pathologic parameters as well as a detailed analysis of the position of OTSCC cells from microanatomic and topographic standpoints.

RESULTS

Of the 28 patients included, 71.4% were males, with a mean age of 64.9 years. Nine (32.1%) patients presented satellitosis, which was always located within the T-N tract. OTSCCs displaying satellitosis had a significantly higher median pathologic depth of invasion (DOI). A radiologic and pathological DOI > 15 mm significantly predicted the presence of satellites. There was a significant relationship between the presence of satellites and both positive lymph nodes and distant metastases.

CONCLUSION

Approximately one-third of cases of intermediate-to-advanced OTSCC are characterized by tumor satellites located in the T-N tract. DOI exceeding 15 mm and the presence of clinically appreciable nodal metastases best predict the presence of satellitosis. Satellite-bearing OTSCC behave more aggressively, with an increased risk of distant metastasis and reduced survival.

Anti-VEGFR2 neutralising antibody slows the progression of multistep oral carcinogenesis

Angiogenesis plays an important role in cancer growth and metastasis, and it is considered a therapeutic target to control tumour growth following anti-angiogenic therapy. However, it is still unclear when tissues initiate angiogenesis during malignant transformation from premalignant condition and whether this premalignant condition could be a therapeutic target of anti-angiogenic therapy. In this study, we aimed to analyse the onset of angiogenesis by evaluating morphological and functional alterations of microvessels during oral multistep carcinogenesis using a 4-nitroquinoline 1-oxide (4NQO)-induced oral carcinogenesis mouse model. In the study, we initially confirmed that with the use of 4NQO, oral lesions develop in a stepwise manner from normal mucosa through oral epithelial dysplasia (OED) to oral squamous cell carcinoma (OSCC). Evaluation of CD31-immunostained specimens revealed that microvessel density (MVD) increases in a stepwise manner from OEDs. Histological and functional analyses revealed the structural abnormalities and leakage of blood vessels had already taken place in OED. Then we evaluated the expression profiles of Hif1a and Vegfa along with hypoxic status and found that OED exhibited increased Vegfa expression under hypoxic conditions. Finally, we tested the possibility of OEDs as a target of anti-angiogenic therapy and found that anti-VEGFR2 neutralising antibody in OED slowed the disease progression from OED to OSCC. These data indicate that an angiogenic switch occurs at the premalignant stage and morphological, and functional alterations of microvessels already exist in OED. These findings also elucidate the tumour microenvironment, which gradually develops along with carcinogenic processes, and highlight usefulness of the 4NQO-induced carcinogenesis model in the study of epithelial and stromal components, which will support epithelial carcinogenesis. © 2024 The Author(s). The Journal of Pathology published by John Wiley & Sons Ltd on behalf of The Pathological Society of Great Britain and Ireland.

Achieving negative superficial resection margins with NBI and white light in carcinoma oral cavity: Could it be a norm?

INTRODUCTION

In India, oral cavity cancer rates are the highest, largely due to tobacco and areca nut use. The primary goal of oncologic surgery is complete tumor resection with adequate margins, yet no accepted guidelines exist margin identification. NBI enhances mucosal lesion detection and may improve margin assessment in OSCC.

AIMS

This study aims to evaluate the proportion of negative superficial resection margins using NBI and to compare these results with margins assessed using white light (WL) examination.

MATERIALS AND METHODS

The study at AIIMS, Rishikesh, included 38 patients with T1-T3 biopsy-proven OSCC. Surgical margins were marked using WL and NBI. Histopathology classified margins as clear (>5mm), close (1-5 mm), or involved. Sensitivity, specificity, and predictive values of NBI were calculated.

RESULTS

The average NBI examination duration was 227 s. Negative margins were achieved in 68.42 % (>5mm) and 78.94 % (>3mm) of NBI cases, compared to 71.05 % and 84.21 % for WL. NBI had a sensitivity of 12.50 %, specificity of 96.67 %, and overall accuracy of 78.95 %.

DISCUSSION

NBI showed high specificity but low sensitivity. This could be due to the smaller number of patients in NBI positive group. In the present study, the single positive margin identified with NBI could also have been detected with the combined approach of white light and palpation, ensuring that no positive margins were missed.

CONCLUSION

NBI can complement WL for margin assessment in oral SCC but requires a long learning curve and a dedicated team. Integrating NBI into standard protocols could improve surgical outcomes and reduce recurrence.

Can Serum and Saliva Inflammatory Cytokines Be Considered a Reliable Marker in Chronic Oral Graft-Versus-Host Disease Patients?

Background/Objectives: Chronic graft-versus-host disease (cGVHD) and oral lichen planus (LPO) are chronic inflammatory conditions with similar oral manifestations. This study aimed to assess whether serum and salivary cytokines (IL-1α, IL-6, IL-17) could serve as reliable biomarkers for cGVHD. Methods: A prospective cohort study was conducted involving cGVHD patients, LPO patients, and healthy controls. Cytokine levels in serum and saliva were measured by ELISA and compared across the groups using the Kruskal-Wallis test. Results: IL-17 levels were significantly elevated in the serum of cGVHD patients compared to LPO patients and controls (p < 0.05). However, IL-6 and IL-1α did not show significant differences among the groups. A comparison of salivary samples between the three groups did not reach statistical significance (p > 0.05). Conclusions: This study suggests that IL-17 could be a potential biomarker for cGVHD-related inflammation, warranting further investigation. Salivary samples do not seem to be a reliable biological marker for the diagnosis of cGVHD. The findings underline the need for larger studies to validate these preliminary results.

New IPCL Classification Using NBI for Early Detection of OPMDs Malignant Transformation

OBJECTIVES

Introduce a new intrapapillary capillary loop (IPCL) classification using narrow-band imaging (NBI) to diagnose early malignant transformation in oral potentially malignant disorders (OPMDs).

METHODS

In the exploratory phase, NBI images from 241 patients with OPMDs and oral squamous cell carcinoma (OSCC) were assessed for three basic IPCL features-dilation, unevenness, and tortuosity-to identify patterns associated with OPMDs malignant transformation. Chi-square analysis and logistic regression differentiated these patterns between low-risk (no/mild dysplasia) and high-risk (moderate/severe dysplasia, invasive carcinoma) lesions, establishing a new classification system. In the validation phase, the system was applied to 90 patients with histopathological results confirming diagnostic accuracy.

RESULTS

Four distinct IPCL types were identified: normal, dilated, irregular, and chaotic, with increasing odds ratios for high-risk lesions. The ROC curve had an AUC of 0.913, with irregular and chaotic types providing the best diagnostic performance, achieving sensitivities and specificities of 84.2% and 88.4%, respectively. In the validation phase, the new classification achieved an overall diagnostic accuracy of 84.4% and substantial inter-observer consistency (κ = 0.694).

CONCLUSION

The new IPCL classification effectively identifies high-risk oral lesions, enhancing the diagnostic utility of NBI for early detection of OPMDs malignant transformations.

Narrow band imaging in oral cancer did not improve visualisation of the tumour borders: a prospective cohort study

BACKGROUND

In oral cancers, tumour borders are typically defined by white light (WL). Narrow-band imaging (NBI) is an optical endoscopic technique commonly used for the larynx and for cancers of unknown primary. However, evidence for using NBI in oral cancers is insufficient.

AIMS/OBJECTIVES

We investigated whether NBI is a better predictor of the true mucosal tumour borders than WL in oral cancers. Additionally, we examined the agreement between NBI-based Takano intrapapillary capillary loop classifications and pathology reports.

MATERIALS AND METHODS

In this prospective study, the tumour borders were assessed by both NBI and WL at the time of surgical resection and then compared. Pathology reports of the examined areas were used as gold standard.

RESULTS

Forty-nine participants were included. After exclusion of 15 patients due to missing data, 34 were included in analyses. In 26.5% of the assessments, the tumour borders defined by NBI were outside the borders defined by WL. However, 55.5% of these were false-positives.

CONCLUSIONS AND SIGNIFICANCE

The delineation of mucosal tumour borders in oral cancers by NBI was not better than that by WL in this study. Several methodological challenges may have influenced the findings of this study, similar to the limitations reported in previous studies.

Oral Mucosa Capillaroscopy: A Narrative Review

The oral cavity may suffer from diseases and lesions of different natures that can result in changes to the underlying microvasculature. These changes are typically observed during the examination of biopsy samples, but there is still a need to investigate methods for characterizing them in live tissues. Capillaroscopy, a medical imaging technique using polarized light and magnification, has shown promise in providing enhanced imaging of the oral mucosa microvasculature in preliminary studies. The present work proposed to review the literature on what capillaroscopy is, its applications in the imaging of oral mucosa microvasculature, and its diagnostic and prognostic significance in various diseases and conditions. While there is the limited literature available, further research in oral capillaroscopy, particularly in the field of oral oncology, is needed to determine its potential benefits in diagnosing and predicting outcomes for potentially malignant oral disorders and cancers.

Narrow band imaging reveals field cancerisation undetected by conventional white light: Optical diagnosis versus histopathology

OBJECTIVE

To assess whether narrow band imaging (NBI) detects fields of cancerisation around suspicious lesions in the upper aerodigestive tract, which were undetected by white light imaging (WLI).

METHODS

In 96 patients with laryngeal and pharyngeal lesions suspicious for malignancy, 206 biopsies were taken during laryngoscopy: 96 biopsies of suspicious lesions detected by both WLI and NBI (WLI+/NBI+), 60 biopsies adjacent mucosa only suspicious with NBI (WLI-/NBI+), and 46 biopsies of NBI and WLI unsuspicious mucosa (WLI-/NBI-) as negative controls. Optical diagnosis according to the Ni-classification was compared with histopathology.

RESULTS

Signs of (pre)malignancy were found in 88% of WLI+/NBI+ biopsies, 32% of WLI-/NBI+ biopsies and 0% in WLI-/NBI- (p < .001). In 58% of the WLI-/NBI+ mucosa any form of dysplasia or carcinoma was detected.

CONCLUSION

The use of additional NBI led to the detection of (pre)malignancy in 32% of the cases, that would have otherwise remained undetected with WLI alone. This highlights the potential of NBI as a valuable adjunct to WLI in the identification of suspicious lesions in the upper aerodigestive tract.

Evaluation of narrow-band imaging in the diagnosis of sinonasal inverted papilloma

KEY POINTS

Narrow-band imaging (NBI) can be used to differentiate benign sinonasal lesions NBI can be used in the preoperative identification of sinonasal inverted papilloma Future studies can focus on NBI for recurrent inverted papilloma and surgical margin guidance.

Comparison of narrow-band imaging with autofluorescence imaging for endoscopic detection of squamous cell carcinoma of the tonsil

PURPOSE

Early detection of mucosal neoplastic lesions is crucial for a patient's prognosis. This has led to the development of effective optical endoscopic diagnostic methods such as narrow band imaging (NBI) and autofluorescence (AFI). Independent of each other, both of these methods were proven useful in the detection of mucosal neoplasias. There are limited reported data comparing both methods for oropharyngeal cancer diagnostics. The aim of the study was to compare NBI and AFI endoscopic visualization of signs in identifying tonsillar squamous cell carcinoma (SCC) and assessing its extent and to determine whether the score was related to the evaluator's experience.

METHODS

Patients with tonsillar SCC underwent endoscopic pharyngeal examination using NBI and AFI. Fiftyseven video sequences of examinations of lesions proven to be SCC were evaluated by three reviewers. The accuracy of determination of lesion extent and visualization of its endoscopic signs of malignancy were evaluated.

RESULTS

Endoscopic visualization of tumour spread was significantly better using AFI than NBI (p = 0.0003). No significant difference was found between NBI and AFI in the visualization of endoscopic malignancy determining signs (p = 0.1405). No significant difference was found among the three reviewers in the visualization of tumour spread and for identifying malignancy-determining signs in NBI endoscopy or AFI endoscopy.

CONCLUSIONS

The results show that AFI obtained better results for assessing the extent of tonsillar cancers than NBI. Both methods were proven to be equal in the visualization of endoscopic malignancy-determining signs. Both are useful even for less experienced evaluators.

Scanning darkfield high-resolution microendoscope for label-free microvascular imaging

Characterization of microvascular changes during neoplastic progression has the potential to assist in discriminating precancer and early cancer from benign lesions. Here, we introduce a novel high-resolution microendoscope that leverages scanning darkfield reflectance imaging to characterize angiogenesis without exogenous contrast agents. Scanning darkfield imaging is achieved by coupling programmable illumination with a complementary metal-oxide semiconductor (CMOS) camera rolling shutter, eliminating the need for complex optomechanical components and making the system portable, low-cost (<$5,500) and simple to use. Imaging depth is extended by placing a gradient-index (GRIN) lens at the distal end of the imaging fiber to resolve subepithelial microvasculature. We validated the capability of the scanning darkfield microendoscope to visualize microvasculature at different anatomic sites in vivo by imaging the oral cavity of healthy volunteers. Images of cervical specimens resected for suspected neoplasia reveal distinct microvascular patterns in columnar and squamous epithelium with different grades of precancer, indicating the potential of scanning darkfield microendoscopy to aid in efforts to prevent cervical cancer through early diagnosis.

Narrow-band imaging features of oral lichenoid conditions: A multicentre retrospective study

OBJECTIVE

Narrow-band imaging (NBI), which highlights epithelial intrapapillary capillary loops (IPCLs) classified into five patterns (0 toIV) with increasing correlation to malignancy, has demonstrated effectiveness for detection of oral squamous cell carcinoma (OSCC). Lack of standardised procedures limits its use for routine inspection of oral lichenoid lesions including oral lichen planus (OLP), oral lichenoid lesion (OLL) and oral lichenoid reaction (OLR). The aim of this study was to analyse IPCL patterns of such lesions, assessing correlations with histopathological outcomes.

MATERIALS AND METHODS

A multicentre, retrospective study was performed on 84 patients who underwent NBI and subsequent biopsy for suspected OLP/OLL/OLR. Patients were examined with Evis Exera III NBI system. Recorded NBI video endoscopies were evaluated to assess IPCL patterns and correlated with histopathological outcomes.

RESULTS

No significant differences were detected among OLP/OLL/OLR on NBI inspection. All lichenoid lesions were significantly related to low-grade (0-II) IPCL patterns, clearly distinguishable from OSCC, showing pattern IV (p < 0.05).

CONCLUSIONS

NBI cannot discern among OLP/OLL/OLR lesions. Interpretation should be modulated when assessing lichenoid lesions. NBI has potential to discern malignant transformation occurring in lichenoid lesions undergoing long-term follow-up, as IPCL pattern IV may be used as a clinical marker of malignancy arising in chronic inflammatory lesions.

The Role of Peritumoral Depapillation and Its Impact on Narrow-Band Imaging in Oral Tongue Squamous Cell Carcinoma

A recent study reported that the occurrence of depapillated mucosa surrounding oral tongue squamous cell carcinomas (OTSCC) is associated with perineural invasion (PNI). The present study evaluates the reliability of depapillation as a PNI predictor and how it could affect narrow-band imaging (NBI) performance. This is thus a retrospective study on patients affected by OTSCC submitted to radical surgery. The preoperative endoscopy was evaluated to identify the presence of depapillation. Differences in distribution between depapillation and clinicopathological variables were analyzed. NBI vascular patterns were reported, and the impact of depapillation on those was studied. We enrolled seventy-six patients. After evaluation of the preoperative endoscopies, 40 (53%) patients had peritumoral depapillation, while 59 (78%) had a positive NBI pattern. Depapillation was strongly correlated to PNI, 54% vs. 28% (p = 0.022). Regarding the NBI pattern, there was no particular association with depapillation-associated tumors. The presence of depapillation did not affect the intralesional pattern detected by the NBI, while no NBI-positive pattern was found in the depapillation area. Finally, the NBI-guided resection margins were not affected by depapillation. Peritumoral depapillation is a reliable feature for PNI in OTSCC. NBI margin detection is not impaired by depapillation.

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.

Accuracy of narrow band imaging for detecting the malignant transformation of oral potentially malignant disorders: A systematic review and meta-analysis

Objective

Oral potentially malignant disorders (OPMDs) are a spectrum of diseases that harbor the potential of malignant transformation and developing into oral squamous cell carcinoma (OSCC). Narrow band imaging (NBI) has been clinically utilized for the adjuvant diagnosis of OPMD and OSCC. This study aimed to comprehensively evaluate the diagnostic accuracy of NBI for malignant transformations of OPMD by applying the intraepithelial papillary capillary loop (IPCL) classification approach.

Methods

Studies reporting the diagnostic validity of NBI in the detection of OPMD/OSCC were selected. Four databases were searched and 11 articles were included in the meta-analysis. We performed four subgroup analyses by defining IPCL I/II as negative diagnostic results and no/mild dysplasia as negative pathological outcome. Pooled data were analyzed using random-effects models. Meta-regression analysis was performed to explore heterogeneity.

Results

After pooled analysis of the four subgroups, we found that subgroup 1, defining IPCL II and above as a clinically positive result, demonstrated the most optimal overall diagnostic accuracy for the malignant transformation of OPMDs, with a sensitivity and specificity of NBI of 0.87 (95% confidence interval (CI) [0.67, 0.96], p < 0.001) and 0.83 [95% CI (0.56, 0.95), p < 0.001], respectively; while the other 3 subgroups displayed relatively low sensitivity or specificity.

Conclusions

NBI is a promising and non-invasive adjunctive tool for identifying malignant transformations of OPMDs. The IPCL grading is currently a sound criterion for the clinical application of NBI. After excluding potentially false positive results, these oral lesions classified as IPCL II or above are suggested to undergo biopsy for early and accurate diagnosis as well as management.

Implementation of Routine Endoscopy with Narrow Band Imaging in the Evaluation of Oral and Upper Airways Lesions in Oral Chronic Graft-Versus-Host Disease: A Preliminary Study

(1) Background: The aim of our study is to investigate the main oral lesion patterns in patients with oral graft-versus-host disease and to describe and validate the use of endoscopy enhanced with narrow-band imaging (NBI) as a personalized, reliable and user-friendly tool for the early detection of oral potentially diseases. (2) Methods: We retrospectively evaluated the medical records of 20 patients with chronic GVHD and with oral manifestations, who were referred to our “Interdisciplinary Center for Oropharyngeal Pathology (CIPO)” from January 2017 to July 2022. (3) Results: Data on GVHD, oral localization and NBI endoscopic evaluation are collected. A total of six mucositis, one mucosal erythematous change, ten lichenoid-like changes, eight erosive lesions, one leukoplakia, two erythroplakia and two case of blisters were observed. Two vascular abnormalities were seen with NBI, leading to one excisional biopsy. The patient was diagnosed with squamous cell carcinoma. (4) Conclusion: Our study is the first to highlight the relevance of the routine use of endoscopy with NBI in patients with oral chronic GVHD. We highlighted its role as a reliable, reproducible, easy-to-use and tailor-made tool in the follow-up of those patients and to allow an earlier identification of aberrant neoangiogenesis related to oral potentially malignant disorders and oral cancer.

Non-invasive imaging of oral potentially malignant and malignant lesions: A systematic review and meta-analysis

Non-invasive (NI) imaging techniques have been developed to overcome the limitations of invasive biopsy procedures, which is the gold standard in diagnosis of oral dysplasia and Oral Squamous Cell Carcinoma (OSCC). This systematic review and meta- analysis was carried out with an aim to investigate the efficacy of the NI-imaging techniques in the detection of dysplastic oral potentially malignant disorders (OPMDs) and OSCC. Records concerned in the detection of OPMDs, Oral Cancer were identified through search in PubMed, Science direct, Cochrane Library electronic database (January 2000 to October 2020) and additional manual searches. Out of 529 articles evaluated for eligibility, 56 satisfied the pre-determined inclusion criteria, including 13 varying NI-imaging techniques. Meta-analysis consisted 44 articles, wherein majority of the studies reported Autofluorescence (AFI-38.6%) followed by Chemiluminescence (CHEM), Narrow Band Imaging (NBI) (CHEM, NBI-15.9%), Fluorescence Spectroscopy (FS), Diffuse Reflectance Spectroscopy (DRS), (FS, DRS-13.6%) and 5aminolevulinic acid induced protoporphyrin IX fluorescence (5ALA induced PPIX- 6.8%). Higher sensitivities (Sen) and specificities (Spe) were obtained using FS (Sen:74%, Spe:96%, SAUC=0.98), DRS (Sen:79%, Spe:86%, SAUC = 0.91) and 5 ALA induced PPIX (Sen:91%, Spe:78%, SAUC = 0.98) in the detection of dysplastic OPMDs from non-dysplastic lesions(NDLs). AFI, FS, DRS, NBI showed higher sensitivities and SAUC (>90%) in differentiating OSCC from NDLs. Analysed NI-imaging techniques suggests the higher accuracy levels in the diagnosis of OSCC when compared to dysplastic OPMDs. 5 ALA induced PPIX, DRS and FS showed evidence of superior accuracy levels in differentiation of dysplastic OPMDs from NDLs, however results need to be validated in a larger number of studies.

Diagnostic Accuracy of High-Grade Intraepithelial Papillary Capillary Loops by Narrow Band Imaging for Early Detection of Oral Malignancy: A Cross-Sectional Clinicopathological Imaging Study

This study aimed to clarify the advantages and disadvantages of conventional visual inspection (CVI), endoscopic white light imaging (WLI), and narrow-band imaging (NBI) and to examine the diagnostic accuracy of intraepithelial papillary capillary loops (IPCL) for the detection of oral squamous cell carcinoma (OSCC). This cross-sectional study included 60 participants with oral mucosal diseases suspected of having oral potentially malignant disorders (OPMDs) or OSCC. The patients underwent CVI, WLI, NBI, and incisional biopsy. Images were evaluated to assess the lesion size, color, texture, and IPCL. Oral lichen planus (OLP) and oral leukoplakia lesions were observed in larger areas with NBI than with WLI; 75.0% were associated with low-grade (Type 0-II) IPCL. Various types of oral leukoplakia were seen; however, all OSCC cases showed high-grade (Type III-IV) IPCL. The diagnostic accuracy of high-grade IPCL for OSCC showed a sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of 100%, 80.9%, 59.1%, 100%, and 85.0%, respectively. A non-homogeneous lesion with high-grade IPCL strongly suggested malignancy. Overall, our results indicate that WLI and NBI are powerful tools for detecting precancerous and cancerous lesions using IPCL. However, NBI is influenced by mucosal thickness; therefore, image interpretation is important for accurate diagnosis.

In vivo lensless microscopy via a phase mask generating diffraction patterns with high-contrast contours

The simple and compact optics of lensless microscopes and the associated computational algorithms allow for large fields of view and the refocusing of the captured images. However, existing lensless techniques cannot accurately reconstruct the typical low-contrast images of optically dense biological tissue. Here we show that lensless imaging of tissue in vivo can be achieved via an optical phase mask designed to create a point spread function consisting of high-contrast contours with a broad spectrum of spatial frequencies. We built a prototype lensless microscope incorporating the 'contour' phase mask and used it to image calcium dynamics in the cortex of live mice (over a field of view of about 16 mm2) and in freely moving Hydra vulgaris, as well as microvasculature in the oral mucosa of volunteers. The low cost, small form factor and computational refocusing capability of in vivo lensless microscopy may open it up to clinical uses, especially for imaging difficult-to-reach areas of the body.

Optical Imaging in the Diagnosis of OPMDs Malignant Transformation

Oral potentially malignant disorders (OPMDs) are a heterogeneous group of oral lesions with a variable risk of malignant transformation to oral squamous cell carcinoma. The current OPMDs malignant transformation screening depends on conventional oral examination (COE) and is confirmed by biopsy and histologic examination. However, early malignant lesions with subtle mucosal changes are easily unnoticed by COE based on visual inspection and palpation. Optical techniques have been used to determine the biological structure, composition, and function of cells and tissues noninvasively by analyzing the changes in their optical properties. The oral epithelium and stroma undergo persistent structural, functional, and biochemical alterations during malignant transformation, leading to variations in optical tissue properties; optical techniques are thus powerful tools for detecting OPMDs malignant transformation. The optical imaging methods already used to detect OPMDs malignant transformation in vivo include autofluorescence imaging, narrowband imaging, confocal reflectance microscopy, and optical coherence tomography. They exhibit advantages over COE in detecting biochemical or morphologic changes at the molecular or cellular level in vivo; however, limitations also exist. This article comprehensively reviews the various real-time in vivo optical imaging methods used in the adjunctive diagnosis of OPMDs malignant transformation. We focus on the principles of these techniques, review their clinical application, and compare and summarize their advantages and disadvantages. Finally, we conclude with a discussion of current challenges and future directions of this field.

Leukoplakia: An Invasive Cancer Hidden within the Vocal Folds. A Multivariate Analysis of Risk Factors

Introduction

Discerning the preoperative nature of vocal fold leukoplakia (VFL) with a substantial degree of certainty is fundamental, seeing that the histological diagnosis of VFL includes a wide spectrum of pathology and there is no consensus on an appropriate treatment strategy or frequency of surveillance. The goal of our study was to establish a clear schedule of the diagnostics and decision-making in which the timing and necessity of surgical intervention are crucial to not miss this cancer hidden underneath the white plaque.

Material and Methods

We define a schedule as a combination of procedures (white light and Narrow Band Imaging diagnostic tools), methods of evaluating the results (a combination of multiple image classifications in white light and Narrow Band Imaging), and taking into account patient-related risk factors, precise lesion location, and morphology. A total number of 259 patients with 296 vocal folds affected by leukoplakia were enrolled in the study. All patients were assessed for three classifications, in detail according to Ni 2019 and ELS 2015 for Narrow Band Imaging and according to Chen 2019 for white light. In 41 of the 296 folds (13.9%), the VFL specimens in the final histology revealed invasive cancer. We compared the results from the classifications to the final histology results.

Results

The results showed that the classifications and evaluations of the involvement of anterior commissure improve the clinical utility of these classifications and showed improved diagnostic performance. The AUC of this model was the highest (0.973) with the highest sensitivity, specificity, PPV, and NPV (90.2%, 89%, 56.9%, and 98.3%, respectively).

Conclusion

The schedule that combines white light and Narrow Band Imaging, with a combination of the two classifications, improves the specificity and predictive value, especially of anterior commissure involvement.

Clinical value of entire-circumferential intraoperative frozen section analysis for the complete resection of superficial squamous cell carcinoma of the tongue

OBJECTIVES

We aimed to evaluate the clinical value of an entire-circumferential intraoperative frozen section analysis (e-IFSA) for the complete resection of superficial squamous cell carcinoma (SCC) of the tongue.

MATERIALS AND METHODS

A total 276 specimens from 51 patients with pT1-2, N0, mucosal or submucosal invasion SCC were analyzed to evaluate the diagnostic accuracy of the e-IFSA and the added value of the e-IFSA to iodine staining. The e-IFSA results were compared with the final histologic results obtained using permanent sections. All specimens for the e-IFSA were taken over the entire circumference 5 mm outside from the iodine unstained areas. The outline of the main resected specimen after taking these outer mucosal specimens were defined as the surgical margins determined by iodine staining alone.

RESULTS

The e-IFSA results were in excellent agreement with final histological results (Cohen's kappa value: 0.85) and the e-IFSA showed high sensitivity (100%) and high negative predictive value (100%). The actual complete resection rate with an e-IFSA was 100% (51/51), and no patient required additional resection after surgery. In contrast, 10/51 patients (20%) patients showed residual atypical mucosal epithelium at or beyond the margin determined by iodine staining alone; this difference was statistically significant (P = 0.002). The 5-year local control rate and 5-year overall survival rate after this procedure were both 100%.

CONCLUSION

An e-IFSA has additional value when performed in conjunction with iodine staining. An e-IFSA would be useful for achieving complete resection of superficial SCC of the tongue.

In Vivo Imaging-Based Techniques for Early Diagnosis of Oral Potentially Malignant Disorders-Systematic Review and Meta-Analysis

Objectives: Oral potentially malignant disorders (OPMDs) are lesions that may undergo malignant transformation to oral cancer. The early diagnosis and surveillance of OPMDs reduce the morbidity and mortality of patients. Diagnostic techniques based on medical images analysis have been developed to diagnose clinical conditions. This systematic review and meta-analysis aimed to evaluate the efficacy of imaging-based techniques compared to the gold standard of histopathology to assess their ability to correctly identify the presence of OPMDs. Design: Literature searches of free text and MeSH terms were performed using MedLine (PubMed), Scopus, Google Scholar, and the Cochrane Library (from 2000 to 30 June 2020). The keywords used in the search strategy were: (“oral screening devices” or “autofluorescence” or “chemiluminescence” or “optical imaging” or “imaging technique”) and (“oral dysplasia” or “oral malignant lesions” or “oral precancerosis”). Results: The search strategy identified 1282 potential articles. After analyzing the results and applying the eligibility criteria, the remaining 43 papers were included in the qualitative synthesis, and 34 of these were included in the meta-analysis. Conclusions: None of the analyzed techniques based on assessing oral images can replace the biopsy. Further studies are needed to explore the role of techniques-based imaging analysis to identify an early noninvasive screening method.

An overview of the current clinical status of optical imaging in head and neck cancer with a focus on Narrow Band imaging and fluorescence optical imaging

Early and accurate identification of head and neck squamous cell carcinoma (HNSCC) is important to improve treatment outcomes and prognosis. New optical imaging techniques may assist in both the diagnostic process as well as in the operative setting by real-time visualization and delineation of tumor. Narrow Band Imaging (NBI) is an endoscopic technique that uses blue and green light to enhance mucosal and submucosal blood vessels, leading to better detection of (pre)malignant lesions showing aberrant blood vessel patterns. Fluorescence optical imaging makes use of near-infrared fluorescent agents to visualize and delineate HNSCC, resulting in fewer positive surgical margins. Targeted fluorescent agents, such as fluorophores conjugated to antibodies, show the most promising results. The aim of this review is: (1) to provide the clinical head and neck surgeon an overview of the current clinical status of various optical imaging techniques in head and neck cancer; (2) to provide an in-depth review of NBI and fluorescence optical imaging, as these techniques have the highest potential for clinical implementation; and (3) to describe future improvements and developments within the field of these two techniques.

The role of NBI with flexible video-endoscope in the follow-up of head and neck cancer patients: a prospective study

PURPOSE

Narrow band imaging (NBI) enhances mucosal vasculature and could help in the identification of recurrences. We assessed the effectiveness of NBI with flexible video-endoscope in the early detection of recurrence after treatment of head and neck squamous cell carcinoma, its diagnostic advantage over high-definition white-light (HD WL) endoscopy, also in relation to recurrence site, and the influence of previous radiotherapy (RT) or chemotherapy (CT). Moreover, we investigated the association between index tumor site and the risk of developing recurrence, and the relation between index tumor site and recurrence site.

METHODS

From January 2018 to November 2020, 160 patients previously treated with surgery and/or RT ± CT were evaluated using NBI with flexible video-endoscope. Sensitivity, specificity, positive/negative predictive value, and accuracy were calculated for NBI and HD WL, and compared using the McNemar test. The Fisher exact test was used to compare the other associations investigated.

RESULTS

The difference between NBI and HD WL sensitivity was statistically significant (p < 0.001). The NBI diagnostic advantage was 62.5%, highest in the hypopharynx (p = 0.05), and was not influenced by previous RT or CT (p = 0.49). Index tumor site statistically related with recurrence site (p < 0.001), but not with the risk of developing recurrence (p = 0.81).

CONCLUSION

NBI with flexible video-endoscope could represent a valid option to detect recurrence early during the follow-up, especially in a difficult-to-visualize site such as the hypopharynx.

Noninvasive Imaging Methods to Improve the Diagnosis of Oral Carcinoma and Its Precursors: State of the Art and Proposal of a Three-Step Diagnostic Process

Simple Summary

Oral squamous cell carcinoma (OSCC) accounts for 90–95% of malignant tumors of the lip and oral cavity and is associated with high mortality in the advanced stages. Early diagnosis is a challenge for oral pathologists and dentists, due to the ambiguous appearance of early OSCC, which is often misdiagnosed, mistreated, and associated with diagnostic delay. The gold standards for OSCC diagnosis are biopsy and histopathological assessment, but these procedures are invasive and time-consuming. Adjunctive noninvasive techniques allow the definition of the malignant features of a suspicious lesion in real time and noninvasively, thus improving the diagnostic procedure. The present review aimed to focus on some of the main promising noninvasive imaging techniques, to highlight their perspective adoption in a three-step diagnosis, which is idealistically faster and better, as well as enables the patient’s compliance.

Abstract

Oral squamous cell carcinoma (OSCC) is the most prevalent form of cancer of lips and oral cavity, and its diagnostic delay, caused by misdiagnosis at the early stages, is responsible for high mortality ratios. Biopsy and histopathological assessment are the gold standards for OSCC diagnosis, but they are time-consuming, invasive, and do not always enable the patient’s compliance, mainly in cases of follow-up with the need for more biopsies. The use of adjunctive noninvasive imaging techniques improves the diagnostic approach, making it faster and better accepted by patients. The present review aims to focus on the most consolidated diagnostic techniques, such as vital staining and tissue autofluorescence, and to report the potential role of some of the most promising innovative techniques, such as narrow-band imaging, high-frequency ultrasounds, optical coherence tomography, and in vivo confocal microscopy. According to their contribution to OSCC diagnosis, an ideal three-step diagnostic procedure is proposed, to make the diagnostic path faster, better, and more accurate.

Deep Learning for Automatic Segmentation of Oral and Oropharyngeal Cancer Using Narrow Band Imaging: Preliminary Experience in a Clinical Perspective

Introduction

Fully convoluted neural networks (FCNN) applied to video-analysis are of particular interest in the field of head and neck oncology, given that endoscopic examination is a crucial step in diagnosis, staging, and follow-up of patients affected by upper aero-digestive tract cancers. The aim of this study was to test FCNN-based methods for semantic segmentation of squamous cell carcinoma (SCC) of the oral cavity (OC) and oropharynx (OP).

Materials and Methods

Two datasets were retrieved from the institutional registry of a tertiary academic hospital analyzing 34 and 45 NBI endoscopic videos of OC and OP lesions, respectively. The dataset referring to the OC was composed of 110 frames, while 116 frames composed the OP dataset. Three FCNNs (U-Net, U-Net 3, and ResNet) were investigated to segment the neoplastic images. FCNNs performance was evaluated for each tested network and compared to the gold standard, represented by the manual annotation performed by expert clinicians.

Results

For FCNN-based segmentation of the OC dataset, the best results in terms of Dice Similarity Coefficient (Dsc) were achieved by ResNet with 5(×2) blocks and 16 filters, with a median value of 0.6559. In FCNN-based segmentation for the OP dataset, the best results in terms of Dsc were achieved by ResNet with 4(×2) blocks and 16 filters, with a median value of 0.7603. All tested FCNNs presented very high values of variance, leading to very low values of minima for all metrics evaluated.

Conclusions

FCNNs have promising potential in the analysis and segmentation of OC and OP video-endoscopic images. All tested FCNN architectures demonstrated satisfying outcomes in terms of diagnostic accuracy. The inference time of the processing networks were particularly short, ranging between 14 and 115 ms, thus showing the possibility for real-time application.

Role of Narrow Band Imaging Technology in the Diagnosis and Follow up of Laryngeal Lesions: Assessment of Diagnostic Accuracy and Reliability in a Large Patient Cohort

BACKGROUND

The aim of this study was to assess diagnostic accuracy and reliability of narrow band imaging (NBI) in the differential diagnosis of laryngeal premalignant lesion, early cancers and recurrences.

MATERIAL AND METHODS

We enrolled 231 patients who underwent endoscopic examination with white light endoscopy (WLE) + NBI and divided them into two groups, group A, without previous radiochemotherapy and group B, with previous radiochemotherapy. When indicated, we performed surgical biopsies to evaluate sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), accuracy and likelihood of endoscopic examination comparing WLE alone and WLE + NBI.

RESULTS

A positive NBI lesion, compared with a negative NBI lesion, had a 29.68 (group A) and 13.96 (group B) times higher probability to be histologically positive (i.e., confirmed) compared with WLE alone improving the diagnostic accuracy. In group A, the NBI mode showed excellent sensitivity (95.0%), which was higher than WLE 2 mode (77.5%). However, the greatest differences were recorded regarding specificity (96.8% vs. 40.6%). In group B, both NBI alone and WLE + NBI mode showed a 94.1% specificity compared with WLE alone, which had a maximum specificity of 85.3%. The mode comparison between NBI and WLE in both groups showed a statistically significant difference, with p-values <0.0001.

CONCLUSIONS

NBI represents a reliable technology in challenging situations, especially in the context of post-radiotherapy or post-surgical mucosal changes showing a high NPV. NBI could reduce the number of unnecessary biopsies related to increased microvascular anomaly revelation, which could help to identify early-stage lesions suitable for minimally invasive surgery and, consequently, decrease hospital admissions.

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.

Narrow-Band Imaging in oncologic otorhinolaryngology: State of the art

OBJECTIVES

To describe the diagnostic performance of Narrow Band Imaging (NBI) combined with White Light Imaging (WLI) in the diagnosis of mucosal lesions at each location of the upper aerodigestive tract, for detection of primary tumor in case of carcinoma of unknown primary, for determination of intraoperative resection margins, and to describe its main diagnostic pitfalls.

MATERIAL AND METHODS

A PubMed search was carried out according to the PRISMA method.

RESULTS

Four hundred and seventy-seven articles published between 2007 and 2020 were identified, 133 of which met the study inclusion criteria and were assessed.

CONCLUSION

The current literature seems to support the use of NBI in diagnosis and/or follow-up of (pre-)malignant head & neck tumors, and in the determination of intraoperative resection margins.

Macroscopic and microscopic imaging modalities for diagnosis and monitoring of urogenital schistosomiasis

Urogenital schistosomiasis remains a major global challenge. Optimal management of this infection depends upon imaging-based assessment of sequelae. Although established imaging modalities such as ultrasonography, plain radiography, magnetic resonance imaging (MRI), narrow band imaging, and computerized tomography (CT) have been used to determine tissue involvement by urogenital schistosomiasis, newer refinements in associated technologies may lead to improvements in patient care. Moreover, application of investigational imaging methods such as confocal laser endomicroscopy and two-photon microscopy in animal models of urogenital schistosomiasis are likely to contribute to our understanding of this infection's pathogenesis. This review discusses prior use of imaging in patients with urogenital schistosomiasis and experimentally infected animals, the advantages and limitations of these modalities, the latest radiologic developments relevant to this infection, and a proposed future diagnostic standard of care for management of afflicted patients.

Enhanced detection of oral dysplasia by structured illumination fluorescence lifetime imaging microscopy

We demonstrate that structured illumination microscopy has the potential to enhance fluorescence lifetime imaging microscopy (FLIM) as an early detection method for oral squamous cell carcinoma. FLIM can be used to monitor or detect changes in the fluorescence lifetime of metabolic cofactors (e.g. NADH and FAD) associated with the onset of carcinogenesis. However, out of focus fluorescence often interferes with this lifetime measurement. Structured illumination fluorescence lifetime imaging (SI-FLIM) addresses this by providing depth-resolved lifetime measurements, and applied to oral mucosa, can localize the collected signal to the epithelium. In this study, the hamster model of oral carcinogenesis was used to evaluate SI-FLIM in premalignant and malignant oral mucosa. Cheek pouches were imaged in vivo and correlated to histopathological diagnoses. The potential of NADH fluorescence signal and lifetime, as measured by widefield FLIM and SI-FLIM, to differentiate dysplasia (pre-malignancy) from normal tissue was evaluated. ROC analysis was carried out with the task of discriminating between normal tissue and mild dysplasia, when changes in fluorescence characteristics are localized to the epithelium only. The results demonstrate that SI-FLIM (AUC = 0.83) is a significantly better (p-value = 0.031) marker for mild dysplasia when compared to widefield FLIM (AUC = 0.63).

The role of Narrow Band Imaging (NBI) in the diagnosis of sinonasal diseases

BACKGROUND

Narrow band imaging (NBI) endoscopy is an optical method that helps to characterise tissue vasculature. Its appli- cation in sinonasal pathology remains scarce and a systematic study of its application to rhinology is lacking. The aim of this study is to analyse and describe the normal sinonasal mucosa under NBI light and to characterise the microvascular features of various sinonasal pathologies. We also want to suggest a classification of the patterns, peculiar to this district, and to evaluate whether they can be indicative of a specific physiological or pathological condition.

METHODS

Digital videos and images under white light and NBI of 103 patients (82 evaluated) with 29 sinonasal pathologies and 55 controls (33 evaluated). were independently analysed by three otolaryngologists and the final pattern was then arranged for each image, reaching an agreement between the individual evaluations.

RESULTS

Once the appearance of normal sinonasal (SN) mucosa was established (SN1), four patterns for the pathological mucosa were described and a working classification was proposed (SN2, SN3, SN4, SN5). We calculated specificity (80.6% vs 90.6%), sensi- tivity (20% vs 38.5%), PPV (46.1% vs 50%), NPV (54.7% vs 85.7%) and accuracy (53% vs 80.3%) of the ability of SN4 and SN5 pattern to discriminate between benign and malignant nasal neoformations.

CONCLUSIONS

This is the first study to propose a systematic NBI description and a classification of the vasculature of healthy and pathological mucosa in the sinonasal tract. Our preliminary results show that this technique can help in the workup of several rhinologic conditions and especially in distinguishing benign from malignant tumors.

Narrow-band imaging for screening of oral premalignant or cancerous lesions: A systematic review and meta-analysis

BACKGROUND

It remains unclear whether the use of adjunctive diagnostic screening methods improves the diagnostic efficacies of oral premalignant and cancerous lesions.

OBJECTIVE OF REVIEW

We evaluated the diagnostic accuracy of narrow-band imaging used to detect oral cancer and precancerous lesions defined employing different narrow-band imaging criteria.

TYPE OF REVIEW

Systematic review and meta-analyses.

SEARCH STRATEGY

We searched PubMed, Scopus, the Web of Science, Embase, Google Scholar and the Cochrane Central Register of Controlled Trials to May 2020.

EVALUATION METHODS

Three different criteria for oral mucosal vascular changes using narrow-band imaging were compared: class I: well-demarcated brownish areas with thick dark spots and/or winding vessels; class II: intraepithelial papillary capillary looping of grades 2, 3 and 4; and class III: intraepithelial papillary capillary looping of grades 3 and 4. Methodological quality was assessed using the Quality Assessment of Diagnostic Accuracy Studies (ver. 2) tool. We compared narrow-band imaging to conventional white-light imaging.

RESULTS

We included 10 prospective or retrospective studies (1374 patients). To detect all dysplastic and cancerous lesions, the class I criteria afforded the optimal specificity and sensitivity; the area under the summary receiver operating characteristic curve was 0.918. To detect highly dysplastic and advanced cancerous lesions, the class III criteria afforded appropriate specificity and sensitivity. The summary receiver operating characteristic curve was 0.905. When using the class III criteria, narrow-band imaging afforded better specificity (0.941 [range 0.920, 0.9572], P < .0001) compared to white-light imaging (0.520 [range 0.409, 0.629]). However, the white-light imaging data were inconsistent and the ranges were broad; narrow-band imaging may be considerably more accurate than white-light imaging when using the class III criteria.

CONCLUSION

Narrow-band imaging diagnosed oral premalignant or cancerous lesions much more reliably than white-light imaging.

Narrow band imaging observed oral mucosa microvasculature as a tool to detect early oral cancer: an Indian experience

BACKGROUND

Narrow band imaging (NBI) is a novel method with the potential to improve the diagnostic capability of white-light.

METHODS

A prospective observational study of 50 consecutive patients, with suspicious malignant/premalignant lesions. White-light images were assessed as suspicious for malignancy/negative for malignancy, whereas NBI images were classified based on the IPCL patterns. All lesions underwent biopsy and accuracy was compared with the histopathology (Fig. 1). Fig. 1 Representative images of the IPCL patterns from Types I-IV RESULTS: 25 lesions (49%) were positive for malignancy, 2 (3.9%) lesions showed severe dysplasia, and 24(47%) were considered negative on histopathology. The sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of white light and NBI in detecting invasive carcinoma was 74.07%, 79.17%, 80.00%, 73.08% and 76.47%, and 92.67%, 90.16%, 92.56%, 91.67% and 92.16% respectively. The NBI group had a significantly better sensitivity and specificity to white light. The interobserver concordance was κ = 0.881.

CONCLUSION

NBI is a highly effective tool to detect invasive carcinomas amongst suspicious lesions of the oral cavity.

NBI utility in oncologic surgery: An organ by organ review

The main aims of the oncologic surgeon should be an early tumor diagnosis, complete surgical resection, and a careful post-treatment follow-up to ensure a prompt diagnosis of recurrence. Radiologic and endoscopic methods have been traditionally used for these purposes, but their accuracy might sometimes be suboptimal. Technological improvements could help the clinician during the diagnostic and therapeutic management of tumors. Narrow band imaging (NBI) belongs to optical image techniques, and uses light characteristics to enhance tissue vascularization. Because neoangiogenesis is a fundamental step during carcinogenesis, NBI could be useful in the diagnostic and therapeutic workup of tumors. Since its introduction in 2001, NBI use has rapidly spread in different oncologic specialties with clear advantages. There is an active interest in this topic as demonstrated by the thriving literature. It is unavoidable for clinicians to gain in-depth knowledge about the application of NBI to their specific field, losing the overall view on the topic. However, by looking at other fields of application, clinicians could find ideas to improve NBI use in their own specialty. The aim of this review is to summarize the existing literature on NBI use in oncology, with the aim of providing the state of the art: we present an overview on NBI fields of application, results, and possible future improvements in the different specialties.

Real-Time Optical Vascular Imaging, a new method for the diagnosis and monitoring of oral diseases

INTRODUCTION

Real-Time Optical Vascular Imaging (RTOVI) is a technology developed in the Centre for Oral Clinical & Translational Sciences, within the Faculty of Dentistry, Oral & Craniofacial Sciences, King's College London, that allows rapid and preparation free, in vivo imaging of the microvascular anatomy of the human oral cavity. Microvascular changes are known to be related to disease subtypes, in particular cancer. This makes in vivo microvascular examination clinically valuable. However, at present there is lack of any analytical method able to objectively assess microvascular morphology images.

DISCUSSION

The assessment of microvascular morphology based on a subjective evaluation was proven to be unreliable. There was a need to develop a software-based analysis for in vivo microvascular images to support the validation of RTOVI. This paper reviews the authors work to develop and test an automated microvascular analysis method for RTOVI based on ImageJ, an open-source software. This allowed to determined which parameters offered a more robust mathematical representation of the microvascular anatomy of the gingival margin, such as the mean area per capillary and mean aspect ratio. However, in vivo microvascular images from elsewhere within the oral cavity posed a bigger challenge to the analysis procedure due to the microvascular architectural complexity and poorer contrast. Angiogenesis Analyzer, a well-known ImageJ plugin used for the quantification of in vitro microvascular images, is under development in collaboration with the University of Paris Est Créteil. The aim of this work is to obtain an automated analysis method for in vivo microvascular images able to offer a solid foundation for the diagnostic potential of RTOVI and subsequent clinical integration of this technology.

CONCLUSION

An automated analysis method for in vivo microvascular images is paramount before any attempt to clinically validate RTOVI. Our initial work of testing a software-based analysis demonstrated the effectiveness of some parameters, which is valuable for future work, and led us to move into a more sophisticated method involving customising the Angiogenesis Analyzer plugin. This is an essential step, aiming to extend the potential of in vivo microscopy with the clinical integration of RTOVI.

LAY DESCRIPTION

This article summarises the initial research work done in the field on in vivo microvascular imaging aiming to develop a technique for the diagnosis of oral diseases based on the shape of small blood vessels found just below the surface of the "skin" inside the mouth. This offers the potential to examine lesions without the need to take a sample (biopsy/cutting tissue) to observe it microscopically. This ultimately offers a potential to accelerate diagnostic decision making, avoid unpleasant and often deterrent surgical procedures and reducing diagnostic laboratory time and cost burdens. However, in order to assess images of small blood vessels obtained in clinic, we needed to develop and test a software-based analysis to avoid the subjective human interpretation, known not to work. This article describes the authors journey to achieve an automated and sophisticated analysis method unique in the world for in vivo microvascular images derived from real-time optical vascular imaging.

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.

Relationship between the immunohistological examination and fluorescence visualization of oral squamous cell carcinoma

Disorders of the oral mucosa are considered easy to diagnose since they can be visualized and examined directly. A change in the color of the oral mucosa reflects histopathological changes and is an important diagnostic parameter. However, the subjective perception of color varies. To determine the extent of resection for oral mucosa conditions, it is necessary to digitize the color and perform objective assessments. In recent years, fluorescence visualization devices and analysis software that measure tissue luminance G have been employed for the identification of oral mucosa diseases. Fluorescence visualization is presumably based on the decrease in epithelial flavin adenine dinucleotide content and luminance G values due to the destruction of collagen cross-links [fluorescence visualization loss (FVL)]. However, cases with differences between luminance values and histopathological presentation exist. Therefore, additional factors may affect fluorescence visualization. The present study used a portable, non-contact oral mucosa fluorescence visualization device for luminance measurements in seven patients with oral squamous cell carcinoma. Furthermore, Picro-Sirius Red and immunohistochemical staining were performed for CK13, CK17, Ki67, p53 and E-cadherin in the FVL(+) (lesion) and FVL(−) (resection stump) areas to elucidate the principle of fluorescence visualization. Fluorescence was significantly lower in the FVL(+) than in the FVL(−) areas, and the mean luminance G value was 56. The Picro-Sirius Red stain revealed collagen destruction in the FVL(+) areas but no collagen disruption in the FVL(−) areas. CK13 was negative in the FVL(+) and positive in the FVL(−) areas, whereas the opposite pattern was observed for CK17. In the FVL(+) area, p53 staining was positive. E-cadherin expression was enhanced in the FVL(−) areas and reduced in the FVL(+) areas. Furthermore, the luminance G value tended to be lower in cases with weaker E-cadherin staining. The aforementioned results suggest that decreased E-cadherin expression may be a factor that regulates fluorescence visualization.

The value of narrowband imaging using the Ni classification in the diagnosis of laryngeal cancer

INTRODUCTION

Narrowband imaging (NBI) is a special endoscopic optical enhancement setting allowing better visualization of mucosal microvasculature compared to white light endoscopy. This study evaluates the validity of NBI using the Ni classification in the detection and differentiation of severe dysplasia (SD) and glottic squamous cell carcinoma (SCC).

METHODS

Patients with suspicious vocal cord lesions underwent conventional white light endoscopy followed by clinically indicated biopsy. At the same time, NBI images were obtained and graded independently. Lesions were graded from I to V according to the Ni classification and compared to histopathological findings.

RESULTS

Fifty-two patients were included in this study (40 SCC and 12 SD). The sensitivity and specificity of NBI in diagnosing laryngeal cancer was 95.0% (CI, 83.9%-99.4%) and 83.3% (CI, 51.6%-97.9%), respectively. The negative likelihood ratio was 0.06. Higher Ni grades correlated very strongly with more advanced disease.

CONCLUSIONS

NBI using the Ni classification is a sensitive diagnostic tool for the detection and differentiation of early neoplastic and preneoplastic glottic lesions. As higher Ni classification correlates strongly with advanced disease, it serves as a useful adjunct to white light endoscopy in the diagnosis of laryngeal cancer.Level of Evidence: Level IV.

Ni endoscopic classification for Storz Professional Image Enhancement System (SPIES) endoscopy in the detection of upper aerodigestive tract (UADT) tumours

The diagnostic procedure for upper aerodigestive tract (UADT) tumours is by white light endoscopy (WLE) combined with biopsy. However, WLE has difficulty identifying minute epithelial changes which hinders early diagnosis. Storz Professional Image Enhancement System (SPIES) is designed to enhance the visualization of microvasculature on the mucosal surface and detect any epithelial changes. In this study, we aimed to evaluate the use of Ni endoscopic classification with SPIES endoscopy in the detection of UADT tumours. Fifty-nine patients with suspected UADT tumours underwent WLE followed by SPIES endoscopy. All the tumours were biopsied and sent for histopathological examination (HPE). The kappa index (κ) was used to evaluate the agreement between the methods. The level of agreement between SPIES using Ni classification and HPE showed almost perfect agreement as compared to moderate agreement between WLE and HPE. The sensitivity and specificity for WLE and HPE were 77.5% and 84.2% respectively with positive predictive value (PPV) of 91.2% and negative predictive value (NPV) of 64%. The sensitivity and specificity for SPIES endoscopy using Ni classification and HPE were 97.5% and 94.7% respectively with PPV of 97.5% and NPV of 94.7%. SPIES endoscopy using Ni classification is a valid tool for earlier tumour detection.

The use of Velscope to assess cellular changes occuring in oral premalignancy

Objectives

To improve visualization of suspicious lesions of the oral mucosa and to assess the accuracy of Velscope in assessing cellular changes occurring in oral premalignancy for early diagnosis.

Materials and methods

In this prospective, randomized in-vivo clinical study a total of 250 patients who gave history of chewing tobacco were screened. The selection of the site of biopsy was taken based on the area of loss of fluorescence identified by the Velscope within the lesion. Routine blood investigations were done. A biopsy was performed to confirm the findings of clinical examination. The data was collected and analysed.

Results

Among 200 patients only 110 underwent incisional biopsy. Of these only 89 patients showed neoplastic changes. Of the control biopsies, none of them showed any dysplastic changes. Out of 106 who exhibited speckling under autofluorescence, only 89 showed dysplastic changes whereas only 17 showed no dysplastic changes. Out of these 17 specimens, the histopathological diagnosis of 5 was coated tongue, 3 were pigmented lesions, 3 were geographic tongue and 2 were mucositis. Of the remaining 4, the histopathological diagnosis of 1 was oral submucous fibrosis, 1 was lichen planus and 2 were frictional keratosis.

Conclusion

False positive findings are possible in presence of highly inflamed tissues, and it is possible that use of Velscope alone may result in failure to detect regions of dysplasia, but it has its use definitely to improve clinical decision making about the nature of oral lesions and aids in decisions to biopsy regions of concern. Use of the scope has allowed practitioners to identify the best region for biopsy. It is much better to occasionally sample tissue that turns out to be benign than to fail to diagnose dysplastic or malignant lesions. However, poor specificity is a major limitation for using it as a screening tool.

Oral epithelial dysplasia: Causes, quantification, prognosis, and management challenges

Oral epithelial dysplasia is a spectrum of architectural and cytological epithelial changes caused by accumulation of genetic changes, and is associated with an increased risk of progression to squamous cell carcinoma. It is a microscopic diagnosis of immense clinical importance. The initial reports of oral potentially malignant disorders with oral epithelial dysplasia transforming to oral cancer helped in understanding the nature of oral malignancies. Since then, clinical studies on oral potentially malignant disorders have combined microscopic findings of oral epithelial dysplasia to assess the malignant transformation potential of different grades of epithelial dysplasia. A significant amount of scientific literature has amassed on oral epithelial dysplasia relating to aspects of its diagnosis and management. However, the evidence base is weak as a result of the significant variability of published research. Poorly described study methods, variability in different oral epithelial dysplasia grading systems, inter- and intra-examiner variability causing issues of reliability, inadequate sample size, and inconsistent durations of follow-up are some of the methodological issues contributing to the failure to provide dependable information. Randomized clinical trials on the malignant transformation potential of oral epithelial dysplasia and its treatment outcomes are limited. This comprehensive literature review on oral epithelial dysplasia summarizes the scientific knowledge published in the scientific literature in English since its first description. The historical development, etiological factors, grading systems, diagnostic criteria, assessment of risk factors and prevention of malignant transformation, management principles of different grades of oral epithelial dysplasia (surgical and nonsurgical), recommendations on follow-up, and prognostic indicators are discussed in detail.

Oral lichen planus and other confounding factors in narrow band imaging (NBI) during routine inspection of oral cavity for early detection of oral squamous cell carcinoma: a retrospective pilot study

Background

Narrow Band Imaging is a noninvasive optical diagnostic tool. It allows the visualization of sub-mucosal vasculature; four patterns of shapes of submucosal capillaries can be recognized, increasingly associated with neoplastic transformation. With such characteristics, it has showed high effectiveness for detection of Oral Squamous Cell Carcinoma. Still, scientific literature highlights several bias/confounding factors, such as Oral Lichen Planus. We performed a retrospective observational study on patients routinely examined with Narrow Band Imaging, investigating for bias, confounding factors and conditions that may limit its applicability.

Methods

Age, sex, smoking, use of dentures, history of head & neck radiotherapy, history of Oral Squamous Cell Carcinoma, site of the lesion and thickness of the epithelium of origin were statistically evaluated as possible bias/confounding factors. Pearson’s Chi-squared test, multivariate logistic regression, Positive Predictive Value, Negative Predictive Value, Sensitivity, Specificity, Positive Likelihood Ratio, Negative Likelihood Ratio and accuracy were calculated, normalizing the cohort with/without patients affected by Oral Lichen Planus, to acknowledge its role as bias/confounding factor.

Results

Five hundred fifty-six inspections were performed on 106 oral cavity lesions from 98 patients. Age, sex, smoking, use of dentures and anamnesis of Oral Squamous Cell Carcinoma were not found to influence Narrow Band Imaging. History of head & neck radiotherapy was not assessed due to insufficient sample. Epithelium thickness does not seem to interfere with feasibility. Presence of Oral Lichen Planus patients in the cohort led to false positives but not to false negatives. Among capillary patterns, number IV was the most significantly associated to Oral Squamous Cell Carcinoma (p < 0.001), not impaired by the presence of Oral Lichen Planus patients in the cohort (accuracy: 94.3, 95% confidence interval: 88.1–97.9%; odds ratio: 261.7, 95% confidence interval: 37.7–1815.5).

Conclusion

Narrow Band Imaging showed high reliability in detection of Oral Squamous Cell Carcinoma in a cohort of patients with oral cavity lesions not normalized for bias/confounding factors. Still, Oral Lichen Planus may lead to false positives. Narrow Band Imaging could help in the follow-up of patients with multiple lesions through detection of capillary pattern IV, which seems to be the most significantly associated to neoplastic epithelium.

Intraoperative Margin Control in Transoral Approach for Oral and Oropharyngeal Cancer

OBJECTIVES

Piecemeal resection provides an innovative conceptual tool for margins surveillance because it entails the intraoperative evaluation of the whole resection margins and not just sample points, which should result in a better control of deep margins compared to en bloc resection. Although it is recognized that the intraoperative use of narrow band imaging (NBI) results in a better control of superficial margins, in this exploratory study we investigated whether NBI and piecemeal resection could be used in combination to improve margin control at both superficial and deep levels. Because piecemeal resection is based on frozen section analysis, we wanted to verify its reliability compared to definitive histological examination.

METHODS

The status of resection margins in a group of patients with oral and oropharyngeal cancers treated with NBI and laser CO2 piecemeal resection (group 1) was compared with that of an historical group of patients (group 2) treated with NBI and conventional en bloc resection. In group 1, sensitivity, specificity, and positive and negative predictive values were used to verify the rate of concordance between frozen section and definitive histology.

RESULTS

The difference between deep positive margins in the two groups was statistically significant (P = 0.042). The high sensitivity and specificity (94.6% and 94.7%, respectively) of frozen section analysis also demonstrated its reliability in the examination of larger samples corresponding to the whole margin.

CONCLUSION

Even if our findings are limited by the small number of patients, we are confident that the combined use of NBI and piecemeal resection could represent an attractive surgical strategy to improve margin control.

LEVEL OF EVIDENCE

2b Laryngoscope, 129:1810-1815, 2019.