Contact Endoscopy of mucosal lesions of oral cavity - Preliminary experience

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

Background

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

Methods

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

Results

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

Conclusion

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

Contact endoscopy for detection of residual or recurrent disease after radiotherapy for squamous cell carcinoma of the upper aerodigestive tract

OBJECTIVE

The aim of this study was to evaluate contact endoscopy in detecting local treatment failures post-radiotherapy in squamous cell carcinoma of the upper aerodigestive tract.

METHOD

A total of 135 consecutive patients with suspected residual or recurrent cancer after definitive radiotherapy underwent contact endoscopy before biopsy. Contact endoscopy findings were compared with histopathological examination findings. Contact endoscopy could not be completed in 7 patients (5.9 per cent) and histopathological examination was inconclusive in 5 patients (3.7 per cent). The findings of the remaining 123 patients were compared.

RESULTS

The sensitivity, specificity and accuracy of contact endoscopy were 88.75, 88.72 and 86.99 per cent, respectively, with similar results across various sites of upper aerodigestive tract. Inter-observer kappa value was 0.86 (95 per cent confidence interval: 0.79-0.93). The intra-observer kappa value was 0.93 (95 per cent confidence interval: 0.87-1.00) for the first observer and 0.95 (95 per cent confidence interval: 0.90-1.00) for second and third observers.

CONCLUSION

Contact endoscopy showed the same high sensitivity and specificity with low inter- and intra-observer variability in detecting post-radiotherapy failures in cancer of the upper aerodigestive tract as has been shown in non-irradiated tissues in earlier studies.

Novel automated vessel pattern characterization of larynx contact endoscopic video images

Purpose

Contact endoscopy (CE) is a minimally invasive procedure providing real-time information about the cellular and vascular structure of the superficial layer of laryngeal mucosa. This method can be combined with optical enhancement methods such as narrow band imaging (NBI). However, these techniques have some problems like subjective interpretation of vascular patterns and difficulty in differentiation between benign and malignant lesions. We propose a novel automated approach for vessel pattern characterization of larynx CE + NBI images in order to solve these problems.

Methods

In this approach, five indicators were computed to characterize the level of vessel’s disorder based on evaluation of consistency of gradient and two-dimensional curvature analysis and then 24 features were extracted from these indicators. The method evaluated the ability of the extracted features to classify CE + NBI images based on the vascular pattern and based on the laryngeal lesions. Four datasets were generated from 32 patients involving 1485 images. The classification scenarios were implemented using four supervised classifiers.

Results

For classification of CE + NBI images based on the vascular pattern, polykernel support vector machine (SVM), SVM with radial basis function (RBF), k-nearest neighbor (kNN), and random forest (RF) show an accuracy of 97%, 96%, 96%, and 96%, respectively. For the classification based on the histopathology, Polykernel SVM showed an accuracy of 84%, 86% and 84%, RBF SVM showed an accuracy of 81%, 87% and 83%, kNN showed an accuracy of 89%, 87%, 91%, RF showed an accuracy of 90%, 88% and 91% for classification between benign histopathologies, between malignant histopathologies and between benign and malignant lesions, respectively.

Conclusion

These promising results show that the proposed method could solve the problem of subjectivity in interpretation of vascular patterns and also support the clinicians in the early detection of benign, pre-malignant and malignant lesions.

Support Immersion Endoscopy in Post-Extraction Alveolar Bone Chambers: A New Window for Microscopic Bone Imaging In Vivo

Using an endoscopic approach, small intraoral bone chambers, which are routinely obtained during tooth extraction and implantation, provide visual in vivo access to internal bone structures. The aim of the present paper is to present a new method to quantify bone microstructure and vascularisation in vivo. Ten extraction sockets and 6 implant sites in 14 patients (6 men / 8 women) were examined by support immersion endoscopy (SIE). After tooth extraction or implant site preparation, microscopic bone analysis (MBA) was performed using short distance SIE video sequences of representative bone areas for off-line analysis with ImageJ. Quantitative assessment of the microstructure and vascularisation of the bone in dental extraction and implant sites in vivo was performed using ImageJ. MBA revealed bone morphology details such as unmineralised and mineralised areas, vascular canals and the presence of bleeding through vascular canals. Morphometric examination revealed that there was more unmineralised bone and less vascular canal area in the implant sites than in the extraction sockets.

Enhanced contact endoscopy for the assessment of the neoangiogenetic changes in precancerous and cancerous lesions of the oral cavity and oropharynx

Dysplasia and squamous cell carcinoma of the upper aerodigestive tract show significant neoangiogenesis appearing as subepithelial and epithelial microvascular irregularities that can be detected by Image-Enhanced Endoscopy such as Narrow Band Imaging and Storz Professional Image Enhancement System. In the present study, the most advanced endoscopic enhancement systems were coupled with Contact Endoscopy (Enhanced Contact Endoscopy). This original method improved the identification and the understanding of the neoangiogenetic changes of the chorion in 42 patients with leukoplakia, erythroplakia, and leuko-erythroplakia of the oral cavity and oropharynx. The physiologic and pathologic mucosa was described in five obvious vascular patterns observed at Enhanced Contact Endoscopy ranging from normal to squamous cell carcinoma, passing through inflammation, hyperplasia, and dysplasia. Each vascular pattern was then compared to histology, showing that the microvascular architectural changes seen with Enhanced Contact Endoscopy are almost constant. Sensitivity, specificity, positive predictive value, and negative predictive value in the differentiation between healthy mucosa and inflammation versus pathologic hyperplasia, dysplasia, and carcinoma were, respectively, 96.6, 93.3, 98.2, 87.5, and 95.9 %. Sensitivity and specificity were 100 % in differentiation between non-malignant lesions versus squamous cell carcinoma. Our preliminary experience shows that accuracy of Image-Enhanced Endoscopy in the diagnosis of precancerous lesions and squamous cell carcinoma of the oral cavity and oropharynx can be increased if associated to Contact Endoscopy.