Fluorescence based characterization of early oral squamous cell carcinoma using the Visually Enhanced Light Scope technique

Clinical Experience with Autofluorescence Guided Oral Squamous Cell Carcinoma Surgery

In our study, the effect of the use of autofluorescence (Visually Enhanced Lesion Scope-VELscope) on increasing the success rate of surgical treatment in oral squamous carcinoma (OSCC) was investigated. Our hypothesis was tested on a group of 122 patients suffering from OSCC, randomized into a study and a control group enrolled in our study after meeting the inclusion criteria. The preoperative checkup via VELscope, accompanied by the marking of the range of a loss of fluorescence in the study group, was performed before the surgery. We developed a unique mucosal tattoo marking technique for this purpose. The histopathological results after surgical treatment, i.e., the margin status, were then compared. In the study group, we achieved pathological free margin (pFM) in 55 patients, pathological close margin (pCM) in 6 cases, and we encountered no cases of pathological positive margin (pPM) in the mucosal layer. In comparison, the control group results revealed pPM in 7 cases, pCM in 14 cases, and pFM in 40 of all cases in the mucosal layer. This study demonstrated that preoperative autofluorescence assessment of the mucosal surroundings of OSCC increased the ability to achieve pFM resection 4.8 times in terms of lateral margins.

Autofluorescence Image-Guided Endoscopy in the Management of Upper Aerodigestive Tract Tumors

At this juncture, autofluorescence and narrow-band imaging have resurfaced in the medicine arena in parallel with current technology advancement. The emergence of newly developed optical instrumentation in addition to the discovery of new fluorescence biomolecules have contributed to a refined management of diseases and tumors, especially in the management of upper aerodigestive tract tumors. The advancement in multispectral imaging and micro-endoscopy has also escalated the trends further in the setting of the management of this tumor, in order to gain not only the best treatment outcomes but also facilitate early tumor diagnosis. This includes the usage of autofluorescence endoscopy for screening, diagnosis and treatment of this tumor. This is crucial, as microtumoral deposit at the periphery of the gross tumor can be only assessed via an enhanced endoscopy and even more precisely with autofluorescence endoscopic techniques. Overall, with this new technique, optimum management can be achieved for these patients. Hence, the treatment outcomes can be improved and patients are able to attain better prognosis and survival.

Analyzing the relationship between tissue color observed in VELscope examination and histopathological factors in OSCC patients

OBJECTIVE

Early detection of OSCC is a crucial step towards improving OSCC prognosis. In recent years, novel diagnostic aids such as light-based detection systems have been introduced for early diagnosis. VELscope is one such light-based device which is used to examine tissue fluorescence. Based on different studies, VELscope has a sensitivity of 90% in the diagnosis of oral premalignant and malignant lesions. Tumor depth of invasion and invasive front have recently been proposed as influential factors in OSCC prognosis. Therefore, the aim of this study was to assess the relationship between tissue color seen through this device and tumor depth of invasion.

METHODS & MATERIALS

20 histopathologically approved OSCCs were included in this study. Conventional oral examination was carried out followed by an assessment of the lesion using VELscope. The H&E slides prepared following the final OSCC surgeries were then examined by an oral pathologist to assess tumor depth of invasion (interpreted as low-risk/high-risk), invasivefront (low-risk/high-risk) and perivascular and perineural invasions. Data was transferred to SPSS 16 software. The association between color changes and histopathological factors was analyzed using the fisher's exact and chi-square tests.

RESULTS

The mean age of the patients was 51/5+/-16/74, 60% of which were men. Most lesions were exophytic and the most common color seen during VELscope examination was red. 55% and 50% of the OSCCs showed high-risk tumor depths and high-risk invasive fronts respectively. Perivascular and perineural invasion was seen in 55% and 35% of the samples respectively. Statistical analysis showed that 72/2% of the lesions with high tumor depths and 70% with high-risk invasive fronts were seen as red, although these associations were not significant (P>0/05). Tumor depth was significantly correlated with invasive front (P<0/05).

CONCLUSION

There was no significant relationship between the type of color seen through VELscope and tumor depth of invasion, however most cases with high-risk depth of invasions were red.

Evaluation of Oral Mucosal Lesions Using the IllumiScan® Fluorescence Visualisation Device: Distinguishing Squamous Cell Carcinoma

We evaluated whether fluorescence intensity (FI) and its coefficient of variation (CV) can be used to diagnose squamous cell carcinoma (SCC) through IllumiScan®, an oral mucosa fluorescence visualisation (FV) device. Overall, 190 patients with oral mucosal lesions (OMLs; SCC, 59; non-SCC OMLs, 131) and 49 patients with normal oral mucosa (NOM) were enrolled between January 2019 and March 2021. The FI of the images was analysed using image analysis software. After establishing regions of interest for SCC, non-SCC, and NOM, the average FI, standard deviation (SD), and CV were compared. There was a significant difference in the average FI for all pairs of comparisons. The SD was not significantly different between the SCC and NOM groups (p = 0.07). The CV differed significantly for NOM (p < 0.001) and non-SCC groups (p < 0.001) relative to the SCC group but was not different between NOM and non-SCC groups (p = 0.15). Univariate analysis of SCC and non-SCC groups showed significant differences for all factors, except age. However, multivariate analysis showed a significant intergroup difference only in the CV (p = 0.038). Therefore, analysing the CV in FV images of OML may be useful for the diagnosis of oral cancer.

Role of Fluorescence Imaging Device in Screening of Oral Cancer: A Cross-Sectional Study in Chhattisgarh Population

Background:

Oral squamous cell carcinoma is a major health issue worldwide. Screening and early diagnosis are the key elements for the better prognosis of potentially malignant oral disorders.

Objectives:

This study establishes the effectiveness of fluorescence imaging device in the early detection and precise examination of the normal-appearing oral mucosa of tobacco chewer patients in white light and fluorescence light.

Materials and Methods:

The study consists of a total of 150 patients equally categorized into frequent tobacco chewers with normal mucosa, precancerous lesion, and cancerous lesion. Out of which 10 cases were excluded due to technical errors and consent-related issues. The correlation between examined oral mucosa under white light and fluorescence light was evaluated through a 2 × 3 contingency table Chi-square test.

Results:

Out of 140 participants with a positive cancer diagnosis, there are 43 and 53 patients were sensitive to white light andfluorescence light, respectively. The estimated values for sensitivity and specificity were 0.83 (95% confidence interval: 0.736–0.906) for biopsy report diagnosis.

Conclusions:

Although autofluorescence device plays a critical role in the diagnosis of precancerous oral mucosal lesions in the early stages, the histopathological evaluation remains the gold standard diagnostic approach for this life-threatening disease. Due to the high sensitivity of autofluorescence examination, it has a vital role in determining high-risk oral lesions (precancerous) and oral cancer in mass screening programs for the cancer-prone population.

Histopathological determinants of autofluorescence patterns in oral carcinoma

Biological tissues (including oral mucosa) can absorb and re-emit specific light wavelengths, detectable through spectrophotometric devices. Such a phenomenon is known as "autofluorescence" (AF). Several devices evaluating tissue AF have been developed and commercialized in the last two decades. Among these, the VELscope® system has been proposed as a visual diagnostic aid for potentially malignant disorders and malignant lesions of the oral mucosa. In the present pilot study, we investigated which are the main histopathological features possibly related to variations in AF patterns in a set of 20 oral squamous cell verrucous carcinoma. Among all the histological features investigated, only the mean width of keratin was significantly different between hypofluorescent and hyperfluorescent carcinomas. The results of the present study demonstrate that AF features of oral malignant lesions are significantly associated with the width of their keratin layer.

Differences between auto-fluorescence and tetracycline-fluorescence in medication-related osteonecrosis of the jaw-a preclinical proof of concept study in the mini-pig

Objectives

Fluorescence-guided bone surgery is a well-established technique in the treatment of medication-related osteonecrosis of the jaw. No histopathological evidence for bone auto-fluorescence is currently available, and thus, any differences from tetracycline-fluorescence remain unclear. Therefore, the goals of this study were to find out if macroscopic and histological differences occur between the auto- and tetracycline-fluorescence in the delineation of viable and necrotic jawbone in the mini-pig.

Materials and methods

According to the proof of concept, osteonecrosis was provoked in eight Göttingen minipigs. Pigs were divided into two groups (AF group: no fluorochrome label; TF group: tetracycline label). Delineation of necrosis and viable bone was evaluated in vivo and in vitro macro−/microscopically, correlated to fluorescence properties and compared between the two study groups.

Results

No macroscopic and microscopic clinical differences were seen in fluorescence between the AF and TF groups. Macroscopic and microscopic viable bone fluoresced green, whereas necrotic bone showed no or only pale fluorescence in both groups. The auto-fluorescence was attributable to the arrangements and structure of collagen and the cell-filled bone lacunae.

Conclusion

Neither in vivo nor in vitro macroscopically differences are apparent between the auto-fluorescence and the tetracycline-fluorescence of bone. The auto-fluorescence is attributable to the arrangements and structure of collagen and the cell-filled bone lacunae. Tetracycline-fluorescence is a mixture of tetracycline (at the bone edges with increased bone formation) and large components of auto-fluorescence.

Clinical relevance

Because auto-fluorescence is easy to apply, reproducible, and does not rely on the subjective impression of the surgeon, it promises to be an important standardized alternative to tetracycline-labeled MRONJ therapy.

Multiclass classification of autofluorescence images of oral cavity lesions based on quantitative analysis

Background

Oral cancer is one of the most common diseases globally. Conventional oral examination and histopathological examination are the two main clinical methods for diagnosing oral cancer early. VELscope is an oral cancer-screening device that exploited autofluorescence. It yields inconsistent results when used to differentiate between normal, premalignant and malignant lesions. We develop a new method to increase the accuracy of differentiation.

Materials and methods

Five samples (images) of each of 21 normal mucosae, as well as 31 premalignant and 16 malignant lesions of the tongue and buccal mucosa were collected under both white light and autofluorescence (VELscope, 400-460 nm wavelength). The images were developed using an iPod (Apple, Atlanta Georgia, USA).

Results

The normalized intensity and standard deviation of intensity were calculated to classify image pixels from the region of interest (ROI). Linear discriminant analysis (LDA) and quadratic discriminant analysis (QDA) classifiers were used. The performance of both of the classifiers was evaluated with respect to accuracy, precision, and recall. These parameters were used for multiclass classification. The accuracy rate of LDA with un-normalized data was increased by 2% and 14% and that of QDA was increased by 16% and 25% for the tongue and buccal mucosa, respectively.

Conclusion

The QDA algorithm outperforms the LDA classifier in the analysis of autofluorescence images with respect to all of the standard evaluation parameters.

Early Diagnosis on Oral and Potentially Oral Malignant Lesions: A Systematic Review on the VELscope® Fluorescence Method

The fluorescence method is an innovative technique used by pathologists for examining body mucosa, and for the abnormalities tissue screening, potentially leading to the earlier discovery of pre-cancer, cancer or other disease processes. The early detection is one of the best mechanisms for enabling treatment success, increasing survival rates and maintaining a high quality of life. The purpose of this review is to evaluate the clinical efficiency of this diagnostic tool applied to the oral cavity (VELscope^®). A literature systematic review has been performed. The initial research provided 53 results after applying the inclusion and exclusion criteria, and after a manual screening of the abstracts by the authors, only 25 results were eligible for review. The results and data contained in all the researches, no older than 10 years, were manually evaluated, and provided useful information on this diagnostic method. The VELscope^® mean value about sensitivity and specificity resulted of 70.19% and 65.95%, respectively, by results analysis, but despite this some studies disagree about its clinical effectiveness, and this diagnostic method is still much debated in scientific and clinical medical literature. Surely being able to have efficient and effective tools from this point of view could help the clinician in the diagnosis, and also make timelier the pharmacological or surgical therapy, improving the quality of life of the patient, and in some cases guaranteeing a longer survival term.

Potential role of autofluorescence imaging in determining biopsy of oral potentially malignant disorders: A large prospective diagnostic study

Autofluorescence examination of oral tissues using the VELscope has been suggested as an adjunctive tool for cancer detection and diagnosis. This study aimed to determine the diagnostic value of VELscope in a large prospective study of 517 patients with oral potentially malignant disorders (OPMD). For the outcome assessments of discrimination of carcinoma form general OPMD and distinguishing high-risk lesions (moderate/severe dysplasia and carcinoma) from low-risk lesions (no/mild dysplasia), high sensitivity (100% and 95.9% respectively) and negative predictive value (100% and 98.2% respectively) were observed. All the carcinoma and showed loss of autofluorescence (LAF) and only 3 (0.6%) moderate/severe dysplasia were observed without LAF. These data indicate that the cases without LAF using VELscope substantially rule out the presence of high-risk lesions including cancer. This may prove to be useful specially to alleviate patient anxiety regarding a clinically suspicious oral lesion without the LAF, and to avoid a unnecessary biopsy for these cases. Collectively, a perspective to highlight was that a no biopsy strategy may be appropriate for OPMD without LAF using VELscope after conventional oral examination.

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.

Porphyrinoids in photodynamic diagnosis and therapy of oral diseases

Photodynamic methods have found application not only in the treatment process as photodynamic therapy but also for the early detection of neoplastic lesions and tumors as photodynamic diagnosis. Early detection of the disease allows not only to avoid the patient’s lifetime risk but also significantly reduce the costs of anticancer therapy, which are increasing every year. There is a constant search for new and more effective photosensitizers which will provide safety in therapy while maintaining efficiency. This paper summarizes recent reports focused on the photodynamic diagnosis of oral cancers. Moreover, it shows methods of the photodynamic treatment of oral verrucous hyperplasia, erythroleukoplakia, and oral leukoplakia. The treatment of choice for these diseases is a surgical excision, which always leads to scar formation. Photodynamic therapy provides a new scar-less tool for the treatment.

Fluorescence and Near-Infrared Light Transillumination

This article describes the current applications of various technologies based on either autofluorescence or near-infrared light illumination, tailored to aid practitioners in detecting and quantitatively monitoring oral diseases such as dental caries and oral cancer at the earliest stage of their formation, or in the conservative surgical excision of necrotic bones in diseases such as chronic osteomyelitis, osteoradionecrosis, and medication-related osteonecrosis of the jaw. The data discussed are primarily based on published scientific studies and reviews from case reports, clinical trials, and in vitro and in vivo studies. References have been traced manually, by MEDLINE, or through manufacturer's websites.

An Overview on Current Non-invasive Diagnostic Devices in Oral Oncology

Oral squamous cell carcinoma (OSCC) is the most common head and neck malignancy, and despite advances in cancer therapies, the overall 5-year survival rate has remained below 50% over the past decades. OSCC is typically preceded by potentially malignant disorders (PMD), but distinguishing high-risk from low-risk PMD is challenging. In the last years, several diagnostic methods as light-based detection systems (LBDS) have been proposed to facilitate the detection of OSCC and PMD. Furthermore, the recent evolution of nanotechnology may provide new opportunities to detect PMD and OSCC at an early stage. Indeed, several preclinical studies showed the potential of nanotechnology to enhance diagnostic accuracy. For these reasons, it is fundamental to conduct studies to evaluate the efficacy of nanotechnology implementation in LBDS. The aim of this article is to review the current literature on LBDS and to provide a summary of the sensitivity and specificity of each technique, and possible future applications of nanotechnologies. The LBDS showed great potential for screening and monitoring oral lesions, but there are several factors that hinder an extensive use of these devices. These devices seem to be useful in assessing lesion margins that must be biopsied. However, to date, conventional oral examination, and tissue biopsy remain the gold standard for OSCC diagnosis. The use of nanotechnologies could be the next step in the evolution of LBDS, thus providing devices that can help clinicians to detect and better monitor oral lesions.