Autofluorescence imaging of potentially malignant mucosa lesions

Current advances in noninvasive methods for the diagnosis of oral squamous cell carcinoma: a review

Oral squamous cell carcinoma (OSCC), one of the most common types of cancers worldwide, is diagnosed mainly through tissue biopsy. However, owing to the tumor heterogeneity and other drawbacks, such as the invasiveness of the biopsy procedure and high cost and limited usefulness of longitudinal surveillance, there has been a focus on adopting more rapid, economical, and noninvasive screening methods. Examples of these include liquid biopsy, optical detection systems, oral brush cytology, microfluidic detection, and artificial intelligence auxiliary diagnosis, which have their own strengths and weaknesses. Extensive research is being performed on various liquid biopsy biomarkers, including novel microbiome components, noncoding RNAs, extracellular vesicles, and circulating tumor DNA. The majority of these elements have demonstrated encouraging clinical outcomes in early OSCC detection. This review summarizes the screening methods for OSCC with a focus on providing new guiding strategies for the diagnosis of the disease.

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.

Clinical Evaluation of the Optical Filter for Autofluorescence Glasses for Oral Cancer Curing Light Exposed (GOCCLES®) in the Management of Potentially Premalignant Disorders: A Retrospective Study

Background: Any oral potentially malignant disorders (OPMDs) must be regularly monitored through clinical examination to detect any possible malignant transformation. Conventional intraoral exams, however, can be difficult because these conditions may resemble benign lesions. For this reason, several non-invasive diagnostic technologies have been developed to help the clinician in detecting and distinguishing between cancerous and benign lesions. Epithelial dysplasia can be considered the most important predictor of malignant evolution. Therefore, in this study we aim to evaluate the ability of an optical filter for autofluorescence Glasses for Oral Cancer Curing Light Exposed (GOCCLES^®) and of toluidine blue staining in identifying dysplastic areas in patients with OPMDs. Methods: In this retrospective study, medical records, photographs and videos of 25 patients with oral lesions were analyzed. Forty-two biopsy samples in 25 patients with OPMDs and at least one suspicious oral mucosa lesion that were evaluated in white light, autofluorescence with optical filter GOCCLES^®, toluidine blue staining and then biopsied with histopathological analysis were analyzed. Results: The sensitivity and specificity for the autofluorescence evaluation with GOCCLES^® for identifying dysplasia or carcinoma were 66% and 48%, respectively. The positive and negative predictive values were 34% and 77%, respectively, and the accuracy was 53%. The sensitivity and specificity for toluidine blue staining were 91% and 68%, respectively. The positive and negative predictive values were 55% and 95%, respectively, and the accuracy was 75%. Conclusions: The optical filter for autofluorescence (GOCCLES^®) and toluidine blue staining are simple, inexpensive, rapid and non-invasive procedures that can assist the clinician in distinguishing OPMDs from healthy mucosa but they are not able to distinguish benign and malignant lesions.

Accuracy of autofluorescence and chemiluminescence in the diagnosis of oral Dysplasia and Carcinoma: A systematic review and Meta-analysis

OBJECTIVES

To define the accuracy of autofluorescence-based (AF) and chemiluminescence-based (CL) systems in the diagnosis of oral dysplastic and malignant lesions in addition to the Conventional Oral Examination (COE).

MATERIALS AND METHODS

The study was performed according to the PRISMA-DTA guidelines.

RESULTS

A total of 2631 oral cavity lesions (AF, n = 2076; CL, n = 555) from 26 studies (AF = 17; CL = 9) was used for calculation of diagnostic accuracy parameters. The overall pooled sensitivity and specificity of the AF were 81.3% (95% CI: 74.3% - 87.5%) and 52.1% (95% CI: 36.9% - 67.1%), respectively. Cumulative diagnostic odds ratio (DOR) was 5.44 (95% CI: 2.29 - 10.56) with a significant heterogeneity between studies (I² = 80.7%, 95% CI: 70.0% - 86.7%; p < .05). The overall pooled sensitivity and specificity for the CL were 84.9% (95% CI: 66.7% - 96.7%) and 51.8% (95% CI: 37.3% - 65.9%), respectively. The overall pooled DOR was 8.59 (95% CI: 2.11 - 22.38) with a significant heterogeneity between studies (I² = 65.4%, 95% CI: 29.6% - 83.0%; p < .05).

CONCLUSIONS

AF and CL present a high sensitivity in the diagnosis of dysplastic and malignant oral cavity lesions, demonstrating that diagnostic biopsies may be avoided in case of a negative test result. Both tests have a low specificity, and the reduction of the false positive rate compared to the COE alone remains poor.

Diagnostic tests for oral cancer and potentially malignant disorders in patients presenting with clinically evident lesions

BACKGROUND

Squamous cell carcinoma is the most common form of malignancy of the oral cavity, and is often proceeded by oral potentially malignant disorders (OPMD). Early detection of oral cavity squamous cell carcinoma (oral cancer) can improve survival rates. The current diagnostic standard of surgical biopsy with histology is painful for patients and involves a delay in order to process the tissue and render a histological diagnosis; other diagnostic tests are available that are less invasive and some are able to provide immediate results. This is an update of a Cochrane Review first published in 2015.

OBJECTIVES

Primary objective: to estimate the diagnostic accuracy of index tests for the detection of oral cancer and OPMD, in people presenting with clinically evident suspicious and innocuous lesions.

SECONDARY OBJECTIVE

to estimate the relative accuracy of the different index tests.

SEARCH METHODS

Cochrane Oral Health's Information Specialist searched the following databases: MEDLINE Ovid (1946 to 20 October 2020), and Embase Ovid (1980 to 20 October 2020). The US National Institutes of Health Ongoing Trials Register (ClinicalTrials.gov) and the World Health Organization International Clinical Trials Registry Platform were also searched for ongoing trials to 20 October 2020. No restrictions were placed on the language or date of publication when searching the electronic databases. We conducted citation searches, and screened reference lists of included studies for additional references.

SELECTION CRITERIA

We selected studies that reported the diagnostic test accuracy of the following index tests when used as an adjunct to conventional oral examination in detecting OPMD or oral cavity squamous cell carcinoma: vital staining (a dye to stain oral mucosa tissues), oral cytology, light-based detection and oral spectroscopy, blood or saliva analysis (which test for the presence of biomarkers in blood or saliva).

DATA COLLECTION AND ANALYSIS

Two review authors independently screened titles and abstracts for relevance. Eligibility, data extraction and quality assessment were carried out by at least two authors, independently and in duplicate. Studies were assessed for methodological quality using the Quality Assessment of Diagnostic Accuracy Studies 2 (QUADAS-2). Meta-analysis was used to combine the results of studies for each index test using the bivariate approach to estimate the expected values of sensitivity and specificity.

MAIN RESULTS

This update included 63 studies (79 datasets) published between 1980 and 2020 evaluating 7942 lesions for the quantitative meta-analysis. These studies evaluated the diagnostic accuracy of conventional oral examination with: vital staining (22 datasets), oral cytology (24 datasets), light-based detection or oral spectroscopy (24 datasets). Nine datasets assessed two combined index tests. There were no eligible diagnostic accuracy studies evaluating blood or salivary sample analysis. Two studies were classed as being at low risk of bias across all domains, and 33 studies were at low concern for applicability across the three domains, where patient selection, the index test, and the reference standard used were generalisable across the population attending secondary care. The summary estimates obtained from the meta-analysis were: - vital staining: sensitivity 0.86 (95% confidence interval (CI) 0.79 to 0.90) specificity 0.68 (95% CI 0.58 to 0.77), 20 studies, sensitivity low-certainty evidence, specificity very low-certainty evidence; - oral cytology: sensitivity 0.90 (95% CI 0.82 to 0.94) specificity 0.94 (95% CI 0.88 to 0.97), 20 studies, sensitivity moderate-certainty evidence, specificity moderate-certainty evidence; - light-based: sensitivity 0.87 (95% CI 0.78 to 0.93) specificity 0.50 (95% CI 0.32 to 0.68), 23 studies, sensitivity low-certainty evidence, specificity very low-certainty evidence; and - combined tests: sensitivity 0.78 (95% CI 0.45 to 0.94) specificity 0.71 (95% CI 0.53 to 0.84), 9 studies, sensitivity very low-certainty evidence, specificity very low-certainty evidence.

AUTHORS' CONCLUSIONS

At present none of the adjunctive tests can be recommended as a replacement for the currently used standard of a surgical biopsy and histological assessment. Given the relatively high values of the summary estimates of sensitivity and specificity for oral cytology, this would appear to offer the most potential. Combined adjunctive tests involving cytology warrant further investigation. Potentially eligible studies of blood and salivary biomarkers were excluded from the review as they were of a case-control design and therefore ineligible. In the absence of substantial improvement in the tests evaluated in this updated review, further research into biomarkers may be warranted.

Evaluation of oral potentially malignant disorders with autoflorescence, reflectance spectroscopy and vital staining and their correlation with histopathology - Hospital based prospective study

OBJECTIVES

To evaluate diagnostic efficacy of Identafi® and toluidine blue in screening of Oral Potentially Malignant Disorders (OPMDs).

MATERIALS AND METHODS

Forty nine patients (63 lesions) with OPMDs visiting Department of Oral Medicine and Radiology, B.P.Koirala Institute of Health Science (BPKIHS) were included in the study. After thorough history and oral examination, screening was done by Identafi® followed by toluidine blue staining. Then incisional biopsy under local anesthesia was performed from the site showing positive change followed by histopathological examination.

RESULTS

The overall sensitivity and specificity of Identafi®^'s violet light was 73% and 46.2%. The overall sensitivity and specificity of Identafi®^'s green-amber light were 78.4% and 15.4% respectively. The overall sensitivity and specificity of toluidine blue were 51.4 and 84.6 respectively. A statistically-significant association was observed between the toluidine blue and histopathology results, (p = 0.04), p value set at ≤ 0.05.

CONCLUSION

Identafi®'s violet light and green amber light are more sensitive in detecting true positives. Toluidine blue is highly specific in ruling out true negative cases. The screening of OPMDs will help in selecting proper biopsy site followed by early diagnosis and intervention, hence increasing the prognosis, outcome and decrease complications associated with it.

Diagnostic accuracy of clinical visualization and light-based tests in precancerous and cancerous lesions of the oral cavity and oropharynx: a systematic review and meta-analysis

OBJECTIVE

Evaluate and compare the performance of autofluorescence, chemiluminescence, and clinical visual examination in the detection of oral potentially malignant disorders (OPMD), oral cancer (OC), and oropharyngeal cancer (OPC).

MATERIALS AND METHODS

A systematic review with meta-analysis based on diagnostic test studies. A literature search was carried out in the MEDLINE and EMBASE databases through August 30, 2020. For this review, the quality assessment tool of diagnostic precision studies (QUADAS-2) was used. Hierarchical regression models were used to estimate pooled diagnostic precision values in a random effects model.

RESULTS

A total of 40 studies were identified for this review according to each test evaluated: 5.562 samples for autofluorescence, 1.353 samples for chemiluminescence, and 1.892 samples for clinical examination. The summary measures sensitivity and specificity of the clinical examination were 63% and 78%, respectively, AUC = 0.78 95% CI (0.74-0.81). In the autofluorescence test, these were 86% and 72%, respectively, AUC = 0.86 95% CI (0.83-0.89); and the chemiluminescent test were 67% and 48%, respectively, AUC = 0.59 95% CI (0.54-0.63) CONCLUSIONS: Autofluorescence devices displayed superior accuracy levels in the identification of premalignant lesions and early neoplastic changes compared to clinical examination and chemiluminescent test. Overall, biopsy remains the gold standard for the definitive diagnosis of OPMD, OC, and OPC.

CLINICAL RELEVANCE

Light-based clinical methods such as autofluorescence and chemiluminescence techniques have been used in clinical diagnosis for the differentiation of OPMD and malignant and benign lesions; although detailed visual examination appears to be effective in identifying, previous systematic reviews have not evaluated a relevant number of studies and they did not evaluate the accuracy of the clinical examination.

Non-Invasive Early Detection of Oral Cancers Using Fluorescence Visualization with Optical Instruments

Simple Summary

Oral cancer has a high mortality rate. Then, oral cancer screening is needed for early detection and treatment. Fluorescence visualization is non-invasive, convenient, and in real-time, and examinations can be repeated. Our study aimed to show the usefulness of oral cancer screening with fluorescence visualization. A total of 502 patients were performed using fluorescence visualization that was analyzed using subjective and objective evaluation. Results of this study, subjective evaluation for detection oral cancer was high sensitivity and low specificity, while objective evaluation using imaging processing analysis was high sensitivity and high specificity. Therefore, oral cancer screening using fluorescence visualization is useful for the detection of oral cancer. The widespread use of this screening can reduce the mortality rate of oral cancer.

Abstract

Background: Oral cancer screening is important for early detection and early treatment, which help improve survival rates. Biopsy is the gold standard for a definitive diagnosis but is invasive and painful, while fluorescence visualization is non-invasive, convenient, and real-time, and examinations can be repeated using optical instruments. The purpose of this study was to clarify the usefulness of fluorescence visualization in oral cancer screening. Methods: A total of 502 patients, who were examined using fluorescence visualization with optical instruments in our hospitals between 2014 and 2019, were enrolled in this study. The final diagnosis was performed by pathological examination. Fluorescence visualization was analyzed using subjective and objective evaluations. Results: Subjective evaluations for detecting oral cancer offered 96.8% sensitivity and 48.4% specificity. Regarding the objective evaluations, sensitivity and specificity were 43.7% and 84.6% for mean green value, 55.2% and 67.0% for median green value, 82.0% and 44.2% for coefficient of variation of value, 59.6% and 45.3% for skewness, and 85.1% and 75.8% for value ratio. For the sub-analysis of oral cancer, all factors on objective and subjective evaluation showed no significant difference. Conclusions: Fluorescence visualization with subjective and objective evaluation is useful for oral cancer screening.

Analysis of the results obtained by national research groups with the Russian state cancer program for the screening of diseases of the oral mucosa and the vermillion border

AIMS AND OBJECTIVES

The purpose of the article is to analyze the results obtained by the national research groups with the Russian State Cancer Program for the screening of diseases of the oral mucosa and the vermillion border. This article analyzes the results obtained by national research groups in the implementation of the Russian State Cancer Program.

BACKGROUND

Based on the Department of Therapeutic Dentistry of A.I. Yevdokimov Moscow State University of Medicine and Dentistry, national research groups were created to implement the state program draft for the screening of oncological and precancerous diseases of the oral mucosa and the vermillion border - a grant of the "A" format to support applied research on a competitive basis in the form of subsidies of the federal target program.

MATERIALS AND METHODS

From 2015 to the first half of 2019, the national clinical groups studied the epidemiology (prevalence rate and structure) of oncological and precancerous diseases of the oral mucosa and the vermillion border in 486,059 persons aged 18-92 years living in Tula, the Tula region, Moscow and Noyabrsk as a result of active pathology detection during targeted examination of the population (screening) and appealability in the preclinical period, early, timely and late detection.

RESULTS

the results of the research confirm low cancer alertness of practicing dentists. An individual patient registration card has been developed to systematize data and create a diagnostic register for the screening of cancer and precancerous diseases of the oral mucosa and the vermillion border.

CONCLUSION

A project has been developed to implement the Russian State Cancer Program for oncological and precancerous diseases of the oral mucosa among the population of the Russian Federation.

Does autofluorescence help detect recurrent squamous cell carcinoma? A prospective clinical study

OBJECTIVE

In oral squamous cell carcinoma (OSCC), 20% of patients experience local recurrences. In this study, the addition of autofluorescence to a standard incandescent light examination was evaluated to enhance detection rates of recurrences in OSCC.

STUDY DESIGN

Patients with OSCC who underwent follow-up examinations were included in this prospective cohort study. All patients (with or without recurrences) were examined clinically and with autofluorescence (using VELscope; Mectron, Cologne, Germany) and biopsy was used to examine suspect lesions for recurrences. Variables likely to influence results were analyzed. An analysis of dependencies, a general log-linear analysis, and a binary regression analysis were performed using SPSS version 26 (SPSS Inc., Chicago, IL).

RESULTS

The study included 195 patients and in 39 cases a biopsy was performed. Results showed significantly more recurrences with the addition of autofluorescence to the usual clinical examination (P ≥ .5). Sensitivity was 95.2% and specificity was 100%.

CONCLUSIONS

This study showed the advantages of adding autofluorescence to routine clinical assessments in OSCC follow-up examinations.

CLINICAL TRIAL REGISTRATION

German Clinical Trials Register DRKS-ID: DRKS00004836.

A personalized computational model predicts cancer risk level of oral potentially malignant disorders and its web application for promotion of non-invasive screening

BACKGROUND

Despite their high accuracy to recognize oral potentially malignant disorders (OPMDs) with cancer risk, non-invasive oral assays are poor in discerning whether the risk is high or low. However, it is critical to identify the risk levels, since high-risk patients need active intervention, while low-risk ones simply need to be follow-up. This study aimed at developing a personalized computational model to predict cancer risk level of OPMDs and explore its potential web application in OPMDs screening.

METHODS

Each enrolled patient was subjected to the following procedure: personal information collection, non-invasive oral examination, oral tissue biopsy and histopathological analysis, treatment, and follow-up. Patients were randomly divided into a training set (N = 159) and a test set (N = 107). Random forest was used to establish classification models. A baseline model (model-B) and a personalized model (model-P) were created. The former used the non-invasive scores only, while the latter was incremented with appropriate personal features.

RESULTS

We compared the respective performance of cancer risk level prediction by model-B, model-P, and clinical experts. Our data suggested that all three have a similar level of specificity around 90%. In contrast, the sensitivity of model-P is beyond 80% and superior to the other two. The improvement of sensitivity by model-P reduced the misclassification of high-risk patients as low-risk ones. We deployed model-P in web.opmd-risk.com, which can be freely and conveniently accessed.

CONCLUSION

We have proposed a novel machine-learning model for precise and cost-effective OPMDs screening, which integrates clinical examinations, machine learning, and information technology.

Reproducibility of tissue autofluorescence for screening potentially malignant disorders

Introduction: Direct tissue autofluorescence (AF) visualization devices such as VELscope® are gaining interest to improve early detection of oral potentially malignant disorders (OPMD) and cancers. The main objective of this study was to assess inter-observer reproducibility of incandescent light (IL) and AF observations for OPMD and cancer. Materials and methods: High risk patients (exposed to alcohol or tobacco) were screened by two independent operators with a conventional oral examination (IL) followed by AF examination. The primary endpoint was the inter-observer agreement on the decision to biopsy assessed by kappa coefficients.Accuracy of IL and AF were estimated by the relative true positive rate (RTPR, increase of sensitivity), relative false positive rate (RFPR, loss of specificity) and their ratio. Results: 179 patients were included. 833 lesions were identified after IL and AF. Indication for biopsy was retrieved for 41 patients (61 lesions). Inter-observer agreement on the indications for biopsy was 93.3% after IL (Kappa coefficient 0.88 [0.80, 0.97]) and 96.1% after IL and AF (Kappa coefficient 0.78 [0.66, 0.90]). RTPR was 1.2, RFPR was 1 and their ratio was 1.2. Conclusion: IL and AF examination has shown good inter-observer reproducibility. Adjunction of AF allowed diagnosing more leukoplakia without dysplasia.

A Meta-analysis on efficacy of auto fluorescence in detecting the early dysplastic changes of oral cavity

Background

Light-based detection agents using autofluorescence may be helpful in the detection of early dysplasia, which would otherwise be misdiagnosed as nondysplastic by conventional oral examination (COE) with white light. Visually-enhanced lesion scope (VELscope) is one of such an aid used for the purpose. A meta-analysis was carried out on the sensitivity and specificity of VELscope that would enable in providing evidence of its usage in oral dysplasia.

Materials and Methods

MeSH terms such as auto florescence in oral dysplasia, VELscope, Oral ID, Identifi, in a different medical database such as PubMed, Cochrane, EBSCO, and Google scholar was carried out by four research associates. The total articles available were 242, of which, 230 were excluded based on strict criteria of randomized control trials and proper design. Finally, only 12 studies were chosen for the present analysis. Of 1643 patients from 12 studies, 1264 patients had undergone the autofluorescence examination after the COE. Only 774 patients have shown the loss of fluorescence with VELScope examination and 487 had retained the fluorescence. Biopsy was performed on 1176 patients after the autofluorescence examination in the areas where there was the loss of fluorescence. The available data were subjected to software Review Manager for analysis.

Results and Discussion

Of the 11 studies analyzed, majority of them showed that the autofluorescence device were sensitive enough > 0.70; however, the values of sensitivity and specificities varied significantly. With the VELscope the diagnostic performance of the inexpert examiner was not improved, obtaining a sensitivity of 0.40 (95% of confidence interval [CI]: 0.406-0.773) and a specificity of 0.80 (95% CI: 0.614-0.923).

Conclusion

The new technique may help as an adjunct to histopathology in detecting the dysplasia initially and stop further progression to the carcinoma.

Endogenous Fluorescence Lifetime Imaging (FLIM) Endoscopy For Early Detection Of Oral Cancer And Dysplasia

We have performed a pilot clinical study, in which multispectral endogenous fluorescence (or autofluorescence) lifetime imaging (FLIM) was performed on clinically suspicious oral lesions of 73 patients undergoing tissue biopsy for oral dysplasia and cancer diagnosis. The results from this pilot study indicated that mild-dysplasia and early stage oral cancer could be detected from benign lesions using a computed aided diagnosis system developed based on biochemical and metabolic biomarkers derived from the endogenous FLIM images. The diagnostic performance of this novel FLIM clinical tool was estimated using a leave-onepatient-out cross-validation approach, which reported levels of sensitivity >90%, specificity >85%, and Area Under the Receiving Operating Curve (ROC-AUC) >0.9.

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.

Adjuncts for the evaluation of potentially malignant disorders in the oral cavity: Diagnostic test accuracy systematic review and meta-analysis-a report of the American Dental Association

BACKGROUND

Oral squamous cell carcinoma is the most common manifestation of malignancy in the oral cavity. Adjuncts are available for clinicians to evaluate lesions that seem potentially malignant. In this systematic review, the authors summarized the available evidence on patient-important outcomes, diagnostic test accuracy (DTA), and patients' values and preferences (PVPs) when using adjuncts for the evaluation of clinically evident lesions in the oral cavity.

TYPES OF STUDIES REVIEWED

The authors searched for preexisting systematic reviews and assessed their quality using the Assessing the Methodological Quality of Systematic Reviews tool. The authors updated the selected reviews and searched MEDLINE, Embase, and the Cochrane Central Register of Controlled Trials to identify randomized controlled trials and DTA and PVPs studies. Pairs of reviewers independently conducted study selection, data extraction, and assessment of the certainty in the evidence by using the Grading of Recommendations Assessment, Development and Evaluation approach.

RESULTS

The authors identified 4 existing reviews. DTA reviews included 37 studies. The authors retrieved 7,534 records, of which 9 DTA and 10 PVPs studies were eligible. Pooled sensitivity and specificity of adjuncts ranged from 0.39 to 0.96 for the evaluation of innocuous lesions and from 0.31 to 0.95 for the evaluation of suspicious lesions. Cytologic testing used in suspicious lesions appears to have the highest accuracy among adjuncts (sensitivity, 0.92; 95% confidence interval, 0.86 to 0.98; specificity, 0.94; 95% confidence interval, 0.88 to 0.99; low-quality evidence).

CONCLUSIONS AND PRACTICAL IMPLICATIONS

Cytologic testing appears to be the most accurate adjunct among those included in this review. The main concerns are the high rate of false-positive results and serious issues of risk of bias and indirectness of the evidence. Clinicians should remain skeptical about the potential benefit of any adjunct in clinical practice.

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.

Optical fluorescence imaging in oral cancer and potentially malignant disorders: A systematic review

OBJECTIVES

This study aimed to systematically review the efficacy of direct optical fluorescence imaging as an adjunct to comprehensive oral examination in the clinical evaluation, risk assessment and surgical management of oral cancer and potentially malignant disorders.

METHODS

Studies adopting autofluorescence devices, evaluating the efficacy of comprehensive oral examination and optical fluorescence imaging in detection, visualisation or management of oral squamous cell carcinoma or oral potentially malignant disorders, as well as discriminating oral epithelial dysplasia from other mucosal lesions, were included in the literature search across bibliographic databases until October 2018.

RESULTS

Twenty-seven studies were found to be eligible for inclusion in qualitative analysis. Of these, only six studies demonstrated a low risk of bias across all domains of the methodological assessment tool (QUADAS-2). Optical fluorescence imaging demonstrated positive results, with higher sensitivity scores, increased lesion detection and visualisation than comprehensive oral examination alone in the clinical evaluation of oral squamous cell carcinoma and oral potentially malignant disorders.

CONCLUSIONS

This review provides promising evidence for the utilisation of optical fluorescence imaging as an adjunct to comprehensive oral examination in varying clinical settings. It is important that devices utilising optical fluorescence imaging are viewed strictly as clinical adjuncts and not specifically as diagnostic devices.

Point-of-care, smartphone-based, dual-modality, dual-view, oral cancer screening device with neural network classification for low-resource communities

Oral cancer is a growing health issue in a number of low- and middle-income countries (LMIC), particularly in South and Southeast Asia. The described dual-modality, dual-view, point-of-care oral cancer screening device, developed for high-risk populations in remote regions with limited infrastructure, implements autofluorescence imaging (AFI) and white light imaging (WLI) on a smartphone platform, enabling early detection of pre-cancerous and cancerous lesions in the oral cavity with the potential to reduce morbidity, mortality, and overall healthcare costs. Using a custom Android application, this device synchronizes external light-emitting diode (LED) illumination and image capture for AFI and WLI. Data is uploaded to a cloud server for diagnosis by a remote specialist through a web app, with the ability to transmit triage instructions back to the device and patient. Finally, with the on-site specialist's diagnosis as the gold-standard, the remote specialist and a convolutional neural network (CNN) were able to classify 170 image pairs into 'suspicious' and 'not suspicious' with sensitivities, specificities, positive predictive values, and negative predictive values ranging from 81.25% to 94.94%.

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.

Detection accuracy for epithelial dysplasia using an objective autofluorescence visualization method based on the luminance ratio

The autofluorescence visualization method (AVM) uses blue excitation light to assist in the diagnosis of epithelial dysplasia. It detects epithelial dysplasia as a black area, which is known as fluorescence visualization loss (FVL). In this study, we evaluated the detection accuracy for epithelial dysplasia of the tongue using the objective AVM and assessed its possible clinical utility. Seventy-nine tongue specimens clinically suspected to have leukoplakia or squamous cell carcinoma (SCC) were analyzed. First, the AVM was subjectively performed using the Visually Enhanced Lesion scope (VELscope), and the iodine-staining method was then performed. After biopsy, the histopathological results and the luminance ratio between the lesion and healthy tissue were compared, and a receiver operating characteristic curve was created. The cutoff value for the objective AVM was determined; the lesion was considered FVL-positive or -negative when the luminance ratio was higher or lower than the cutoff value, respectively. The histopathological diagnoses among the 79 specimens were SCC (n=30), leukoplakia with dysplasia (n=34), and leukoplakia without dysplasia (n=15). The cutoff value of the luminance ratio was 1.62, resulting in 66 FVL-positive and 13 FVL-negative specimens. The luminance ratio was significantly higher in the epithelial dysplasia-positive than -negative group (P<0.000 1). The objective AVM showed much higher consistency between histopathological results than did the two methods (kappa statistic=0.656). In conclusion, objective autofluorescence visualization has a potential as an auxiliary method for diagnosis of epithelial dysplasia.

Evaluation of the diagnostic efficacy and spectrum of autofluorescence of benign, dysplastic and malignant lesions of the oral cavity using VELscope

OBJECTIVES

Conventional oral examination and biopsy are the only reliable methods for the early detection of oral cancer at present. Autofluorescence examination of oral tissues using the VELscope has been suggested as an adjunctive tool for cancer detection and diagnosis. The aim of our study was to evaluate the efficacy of the VELscope in recognizing dysplastic and/or neoplastic changes in oral mucosal lesions that were identified on conventional oral examination.

MATERIALS AND METHODS

Two hundred patients with oral mucosal lesions were subjected to conventional oral examination followed by VELscope examination and their autofluorescence characteristics were compared with the histopathological diagnosis. The sensitivity, specificity, positive and negative predictive values of the VELscope examination was calculated.

RESULTS

The VELscope examination showed sensitivity and specificity values of 76% (95% CI: 54.87-90.64%) and 66.29% (95% CI: 58.76-73.24%) respectively while the positive and negative predictive values were 24.36% (95% CI: 19.22-30.36%) and 95.08% (95% CI: 90.52-97.51%) respectively.

CONCLUSION

The VELscope examination alone cannot provide a definitive diagnosis as to the presence of dysplastic tissue change. In spite of having a reasonable sensitivity, the high number of false-positive results limits its efficiency as an adjunct. However, a high negative predictive value can serve to alleviate patient anxiety regarding suspicious mucosal lesions in a general practice setting.

The diagnostic value of the native fluorescence visualization device for early detection of premalignant/malignant lesions of the oral cavity

PURPOSE

The present study aimed to determine the diagnostic value of a native fluorescence visualization device in the identification of oral malignant/dysplastic lesions.

METHODS

This study involved 45 patients who had oral lesions that were suspected to be malignant, potentially malignant, or benign. The patients visited the Oral Medicine Department of the Mashhad Dental School. The sensitivity, specificity, positive and negative predictive values, and likelihood ratio of this device were determined.

RESULTS

The histopathological assessment of samples showed 9 cases of oral squamous cell carcinoma and 12 lesions with dysplasia. Ten samples of dysplastic lesions and all malignant lesions appeared dark or red/orange when examined with the native fluorescence visualization device. In 90% of the dysplastic/malignant lesions, the label-free fluorescence results were positive. The sensitivity, specificity, and positive and negative predictive values of this device were 90%, 15%, 40%, and 71%, respectively.

CONCLUSIONS

The native fluorescence visualization device can be used in specialized centers as an adjunctive device to increase the sensitivity of a clinical examination, but is not capable of distinguishing benign lesions from malignant and dysplastic ones due to its low specificity.

Diagnostic accuracy of Narrow Band Imaging for the detection of oral potentially malignant disorders

OBJECTIVE

To determine the clinical diagnostic accuracy of Narrow Band Imaging(™) for the detection of oral potentially malignant disorders in a prospective series of patients.

MATERIALS AND METHODS

New and existing patients referred to an oral medicine and pathology specialist clinic for assessment of at least one white, red or red-white oral mucosal lesion underwent conventional oral examination, followed by examination with the white light mode and then narrow band imaging mode of a Narrow Band Imaging(™) system. The clinical presentation, microvascular architecture and relevant histopathology of all lesions were recorded.

RESULTS

A total of 272 lesions from 95 patients were observed. The sensitivity, specificity, positive predictive value, negative predictive value and accuracy for the detection of oral potentially malignant disorders or worse by Narrow Band Imaging(™) were 100%, 74.63%, 92.38%, 100% and 93.77%, respectively, when compared with conventional oral examination. Narrow Band Imaging(™) aided the detection of 24 lesions undetected by conventional oral examination and 13 lesions undetected by white light endoscopy.

CONCLUSION

Narrow Band Imaging(™) demonstrates great utility as a visualisation adjunct for detecting and monitoring oral potentially malignant diseases, particularly lesions not identified by conventional oral examination or white light examination alone.

Automated algorithm for actinic cheilitis diagnosis by wide-field fluorescence imaging

Actinic cheilitis (AC) is a disease caused by prolonged and cumulative sun exposure that mostly affects the lower lip, which can progress to a lip squamous cell carcinoma. Routine diagnosis relies on clinician experience and training. We investigated the diagnostic efficacy of wide-field fluorescence imaging coupled to an automated algorithm for AC recognition. Fluorescence images were acquired from 57 patients with confirmed AC and 46 normal volunteers. Three different algorithms were employed: two based on the emission characteristics of local heterogeneity, entropy and intensity range, and one based on the number of objects after K-mean clustering. A classification model was obtained using a fivefold cross correlation algorithm. Sensitivity and specificity rates were 86% and 89.1%, respectively.

Objective Detection of Oral Carcinoma with Multispectral Fluorescence Lifetime Imaging In Vivo

Successful early detection and demarcation of oral carcinoma can greatly impact the associated morbidity and mortality rates. Current methods for detection of oral cancer include comprehensive visual examination of the oral cavity, typically followed by tissue biopsy. A noninvasive means to guide the clinician in making a more objective and informed decision toward tissue biopsy can potentially improve the diagnostic yield of this process. To this end, we investigate the potential of fluorescence lifetime imaging (FLIM) for objective detection of oral carcinoma in the hamster cheek pouch model of oral carcinogenesis in vivo. We report that systematically selected FLIM features can differentiate between low-risk (normal, benign and low-grade dysplasia) and high-risk (high-grade dysplasia and cancer) oral lesions with sensitivity and specificity of 87.26% and 93.96%, respectively. We also show the ability of FLIM to generate "disease" maps of the tissue which can be used to evaluate relative risk of neoplasia. The results demonstrate the potential of multispectral FLIM with objective image analysis as a noninvasive tool to guide comprehensive oral examination.

Accuracy of autofluorescence in diagnosing oral squamous cell carcinoma and oral potentially malignant disorders: a comparative study with aero-digestive lesions

Presently, various studies had investigated the accuracy of autofluorescence in diagnosing oral squamous cell carcinoma (OSCC) and oral potentially malignant disorders (OPMD) with diverse conclusions. This study aimed to assess its accuracy for OSCC and OPMD and to investigate its applicability in general dental practice. After a comprehensive literature search, a meta-analysis was conducted to calculate the pooled diagnostic indexes of autofluorescence for premalignant lesions (PML) and malignant lesions (ML) of the oral cavity, lung, esophagus, stomach and colorectum and to compute indexes regarding the detection of OSCC aided by algorithms. Besides, a u test was performed. Twenty-four studies detecting OSCC and OPMD in 2761 lesions were included. This demonstrated that the overall accuracy of autofluorescence for OSCC and OPMD was superior to PML and ML of the lung, esophagus and stomach, slightly inferior to the colorectum. Additionally, the sensitivity and specificity for OSCC and OPMD were 0.89 and 0.8, respectively. Furthermore, the specificity could be remarkably improved by additional algorithms. With relatively high accuracy, autofluorescence could be potentially applied as an adjunct for early diagnosis of OSCC and OPMD. Moreover, approaches such as algorithms could enhance its specificity to ensure its efficacy in primary care.

Topical MMP beacon enabled fluorescence-guided resection of oral carcinoma

Each year almost 300,000 individuals worldwide are diagnosed with oral cancer, more than 90% of these being oral carcinoma [N. Engl. J. Med.328, 1841993]. Surgical resection is the standard of care, but accurate delineation of the tumor boundaries is challenging, resulting in either under-resection with risk of local recurrence or over-resection with increased functional loss and negative impact on quality of life. This study evaluates, in two pre-clinical in vivo tumor models, the potential of fluorescence-guided resection using molecular beacons activated by metalloproteinases, which are frequently upregulated in human oral cancer. In both models there was rapid (<15 min) beacon activation upon local application, allowing clear fluoresecence imaging in vivo and confirmed by ex vivo fluorescence microscopy and HPLC, with minimal activation in normal oral tissues. Although the tissue penetration was limited using topical application, these findings support further development of this approach towards translation to first-in-human trials.

Autofluorescence based diagnostic techniques for oral cancer

Oral cancer is one of the most common cancers worldwide. Despite of various advancements in the treatment modalities, oral cancer mortalities are more, particularly in developing countries like India. This is mainly due to the delay in diagnosis of oral cancer. Delay in diagnosis greatly reduces prognosis of the treatment and also cause increased morbidity and mortality rates. Early diagnosis plays a key role in effective management of oral cancer. A rapid diagnostic technique can greatly aid in the early diagnosis of oral cancer. Now a day's many adjunctive oral cancer screening techniques are available for the early diagnosis of cancer. Among these, autofluorescence based diagnostic techniques are rapidly emerging as a powerful tool. These techniques are broadly discussed in this review.

A novel multimodal optical imaging system for early detection of oral cancer

OBJECTIVES

Several imaging techniques have been advocated as clinical adjuncts to improve identification of suspicious oral lesions. However, these have not yet shown superior sensitivity or specificity over conventional oral examination techniques. We developed a multimodal, multi-scale optical imaging system that combines macroscopic biochemical imaging of fluorescence lifetime imaging with subcellular morphologic imaging of reflectance confocal microscopy for early detection of oral cancer. We tested our system on excised human oral tissues.

STUDY DESIGN

In total, 4 tissue specimens were imaged. These specimens were diagnosed as either clinically normal, oral lichen planus, gingival hyperplasia, or superficially invasive squamous cell carcinoma. The optical and fluorescence lifetime properties of each specimen were recorded.

RESULTS

Both quantitative and qualitative differences among normal, benign, and squamous cell carcinoma lesions can be resolved with fluorescence lifetime imaging reflectance confocal microscopy. The results demonstrate that an integrated approach based on these two methods can potentially enable rapid screening and evaluation of large areas of oral epithelial tissue.

CONCLUSIONS

Early results from ongoing studies of imaging human oral cavity illustrate the synergistic combination of the 2 modalities. An adjunct device based on such optical characterization of oral mucosa can potentially be used to detect oral carcinogenesis in early stages.

Efficacy of Autofluorescence Imaging as an Adjunctive Technique for Examination and Detection of Oral Potentially Malignant Disorders: A Systematic Review

BACKGROUND

Oral cancer is a serious global issue and early diagnosis of oral cancer is the key in reducing the high mortality rate. Autofluorescence properties of oral mucosa have been gaining interest in the field of early diagnosis of oral premalignant lesions.

OBJECTIVE

The aim of the study was to evaluate the clinical usefulness of an autofluorescence based imaging system to detect oral premalignant and malignant lesions.

MATERIALS AND METHODS

A systematic review of the English-language literature to evaluate the effectiveness of visually enhanced lesion scope (VELscope) published between 1966 and March, 2014 was undertaken. Data relating to study design, sampling and characteristics of the study group, interventions, and reported outcomes and diagnostic value of VELscope were abstracted from articles meeting inclusion and exclusion criteria.

RESULTS

Eleven articles that met the inclusion criteria were included. In nine studies, all the lesions underwent histological assessment, whereas the remaining four studies only performed histological assessment on suspicious lesions. Visually enhanced lesion scope showed high sensitivity values in detecting oral premalignant and malignant lesions. However, most of the studies reported it inability in discriminating dysplasia cases from nondysplasia cases.

CONCLUSION

There is insufficient evidence to support the use of VELscope in primary care setting, however, they may be useful in hands of a specialist.

Autofluorescence imaging in recurrent oral squamous cell carcinoma

The survival of patients with oral cancer is decreased by locoregional recurrence after an initial multimodal treatment. In order to identify lesions in the oral cavity for a possible recurrence, clinical evaluation as well as MRI or CT scanning is advised. The evaluation of mucosa lesions is hampered by changes related to radio- and chemotherapy as well as reconstruction with tissue flaps. Several techniques for easier identification of tissue abnormalities in the oral cavity have been advocated as adjuncts in order to facilitate identification. Especially methods using altered tissue fluorescence have gained much interest during the last decade. The aim of our prospective study was to evaluate fluorescence properties of undiagnosed mucosa lesions with the VELscope device in patients with multimodal treated oral cancer prior to histological confirmation. In total, 41 patients with a history of oral squamous cell carcinomas (OSCC) (19 females and 22 males) with undiagnosed mucosa lesions where included in the study. After clinical evaluation, examination and documentation using the VELscope® device were performed. Then, an incisional biopsy was performed. An autofluorescence loss indicating a malignant or dysplastic mucosa condition could be detected in six patients (14.6 %); however, only one OSCC and one SIN revealed a complete autofluorescence loss. In four patients, OSCC was present in lesions with retained autofluorescence. Sensitivity and specificity for the VELscope® examination to identify malignant oral lesions by autofluorescence were 33.3 and 88.6 %, respectively. The positive and negative predictive values were 33.3 and 88.6 %, respectively. No statistical correlation between gender and lesion appearance versus autofluorescence loss could be detected. In contrast to mucosa lesions in patients with no prior treatment, the autofluorescence evaluation with the VELscope reveals no additional information in our analysis. Accordingly, invasive biopsies as gold standard are still needed to get sufficient evidence regarding potential malignancy in patients after multimodal treatment for oral cancer.

Diagnostic tests for oral cancer and potentially malignant disorders in patients presenting with clinically evident lesions

BACKGROUND

Oral squamous cell carcinoma is the most common form of malignancy of the lip and oral cavity, often being proceeded by potentially malignant disorders (PMD). Early detection can reduce the malignant transformation of PMD and can improve the survival rate for oral cancer. The current standard of scalpel biopsy with histology is painful for patients and involves a delay whilst histology is completed; other tests are available that are unobtrusive and provide immediate results.

OBJECTIVES

PRIMARY OBJECTIVE

To estimate the diagnostic accuracy of index tests for the detection of oral cancer and PMD of the lip and oral cavity, in people presenting with clinically evident lesions.

SECONDARY OBJECTIVE

To estimate the relative accuracy of the different index tests.

SEARCH METHODS

The electronic databases were searched on 30 April 2013. We searched MEDLINE (OVID) (1946 to April 2013) and four other electronic databases (the Cochrane Diagnostic Test Accuracy Studies Register, the Cochrane Oral Health Group's Trials Register, EMBASE (OVID) and MEDION (Ovid)). There were no restrictions on language in the searches of the electronic databases. We conducted citation searches and screened reference lists of included studies for additional references.

SELECTION CRITERIA

We selected studies that reported the diagnostic test accuracy of the following index tests when used as an adjunct to conventional oral examination in detecting PMD or oral squamous cell carcinoma of the lip or oral cavity: vital staining, oral cytology, light-based detection and oral spectroscopy, blood or saliva analysis (which test for the presence of biomarkers in blood or saliva).

DATA COLLECTION AND ANALYSIS

Two review authors independently screened titles and abstracts for relevance. Eligibility, data extraction and quality assessment were carried out by at least two authors, independently and in duplicate. Studies were assessed for methodological quality using QUADAS-2. Meta-analysis was used to combine the results of studies for each index test using the bivariate approach to estimate the expected values of sensitivity and specificity.

MAIN RESULTS

We included 41 studies, recruiting 4002 participants, in this review. These studies evaluated the diagnostic accuracy of conventional oral examination with: vital staining (14 studies), oral cytology (13 studies), light-based detection or oral spectroscopy (13 studies). Six studies assessed two combined index tests. There were no eligible diagnostic accuracy studies evaluating blood or salivary sample analysis.The summary estimates for vital staining obtained from the meta-analysis were sensitivity of 0.84 (95% CI 0.74 to 0.90) with specificity of 0.70 (0.59 to 0.79), with 14 studies were included in the meta-analysis. For cytology, sensitivity was 0.91 (0.81 to 0.96) and specificity was 0.91 (0.81 to 0.95) with 12 studies included in the meta-analysis. For light-based detection, sensitivity was 0.91 (0.77 to 0.97) and specificity was 0.58 (0.22 to 0.87) with 11 studies included in the meta-analysis. The relative test accuracy was assessed by adding covariates to the bivariate analysis, no difference in model fit was observed.

AUTHORS' CONCLUSIONS

The overall quality of the included studies was poor. None of the adjunctive tests can be recommended as a replacement for the currently used standard of a scalpel biopsy and histological assessment. Given the relatively high values of the summary estimates of sensitivity and specificity for cytology, this would appear to offer the most potential. Combined adjunctive tests involving cytology warrant further investigation.

Late stage diagnosis of oral cancer: components and possible solutions

Stage of disease at the diagnosis of oral cancer is thought to be a significant factor in prognosis and outcome (International Agency for Research on Cancer/World Health Organization, 2014). Unfortunately, we continue to diagnose almost 2/3 of these cancers at advanced stages of disease despite the ongoing research for devices/methods to aid the clinicians in detection and accurate oral mucosal lesion diagnosis. This paper explores both the nature of oral cancer and the adjuncts available for detection, and presents the current issues in diagnostic delays of oral cancer detection.

The use of light-based (optical) detection systems as adjuncts in the detection of oral cancer and oral potentially malignant disorders: a systematic review

INTRODUCTION

In recent decades, optical techniques utilising the principles of chemiluminescence and tissue autofluorescence have emerged to facilitate the early detection of any oral mucosal changes suspicious of cancer.

PURPOSE

To evaluate the effectiveness of devices that utilise the principles of chemiluminescence and tissue autofluorescence as adjuncts in the detection of oral cancer and oral potentially malignant disorders (OPMDs).

METHODS

A systematic review of the published literature to evaluate the effectiveness of the ViziLite(®) and ViziLite(®) Plus with toluidine blue, MicroLux™/DL and the VELscope™ as aids in the detection of oral cancer and OPMDs.

RESULTS

Twenty-five primary studies published between 2004 and 2013 satisfied our criteria for selection - 13 utilised chemiluminescence and 12 tissue autofluorescence. Some had utilised both study methods on the same population. Chemiluminescence shows good sensitivity at detecting any OPMDs and oral cancer. However, it preferentially detects leukoplakia and may fail to spot red patches. The additive use of toluidine blue may improve specificity. Tissue autofluorescence is sensitive at detecting white, red and white and red patches, and the area of fluorescence visualisation loss (FVL) often extends beyond the clinically visible lesion. However, in addition to OPMDs, VELScope may detect erythematous lesions of benign inflammation resulting in false-positive test results.

CONCLUSION

There is limited evidence for their use in primary care, and these tools are better suited to specialist clinics in which there is a higher prevalence of disease and where experienced clinicians may better discriminate between benign and malignant lesions.

Assessment of a decision making protocol to improve the efficacy of VELscope™ in general dental practice: a prospective evaluation

BACKGROUND

VELscope™ is a device designed to help detect potentially malignant disorders of the oral mucosa at an early stage using direct tissue autofluorescence. Previous research indicates a high rate of false positives using this device. This study assesses a decision making protocol for the detection of oral mucosal lesions using conventional oral examination and VELscope™ in a general dental practice setting.

MATERIALS AND METHODS

305 patients presenting for general dental treatment were screened by a general dental practitioner (GDP) for oral mucosal lesions using incandescent light (conventional oral examination - COE), followed by VELscope™ and then by correlating the findings from these two examinations. A decision making protocol was followed. Patients were either reviewed or referred to an Oral Medicine specialist (OMS) for consultation, and biopsy was undertaken as required for definitive diagnosis.

RESULTS

146 patients presented with at least one oral mucosal lesion, and a total of 222 lesions were detected. COE detected 161 oral mucosal lesions and an additional 61 lesions were detected with VELscope™. COE alone showed a sensitivity of 44.0% and specificity of 99.0% while VELscope™ alone showed a sensitivity of 64.0% and specificity of 54.3%. Using the decision making protocol, the sensitivity and specificity were 73.9% and 97.9% respectively.

CONCLUSION

Using the decision making protocol proposed in this study allows for the detection of additional oral mucosal lesions requiring specialist referral by incorporating VELscope™ into routine general dental practice, without compromising patient care.

Oral mucosa optical biopsy by a novel handheld fluorescent confocal microscope specifically developed: technologic improvements and future prospects

OBJECTIVE

This pilot study evaluated the baseline effectiveness of a novel handheld fluorescent confocal microscope (FCM) specifically developed for oral mucosa imaging and compared the results with the literature.

STUDY DESIGN

Four different oral sites (covering the mucosa of the lip and of the ventral tongue, the masticatory mucosa of the gingiva, and the specialized mucosa of the dorsal tongue) in 6 healthy nonsmokers were imaged by an FCM made up of a confocal fiberoptic probe ergonomically designed for in vivo oral examination, using light at the wavelength of 457 nm able to excite the fluorophore acriflavine hydrochloride, topically administered. In total, 24 mucosal areas were examined.

RESULTS

The FCM was able to distinctly define epithelial cells, bacterial plaque, and inflammatory cells and to image submucosal structures by detecting their intrinsic fluorescence.

CONCLUSIONS

When compared with other devices, this FCM allowed the user to image each oral site at higher magnification, thus resulting in a clearer view.

Potentially malignant disorders of the oral cavity: current practice and future directions in the clinic and laboratory

Despite commendable progress in the prevention, detection, and treatment of a wide variety of solid tumor types, oral squamous cell carcinoma (OSCC) remains a significant health burden across the globe. OSCC carcinogenesis involves accumulation of genetic alterations that coincide with the multistep malignant transformation of normal oral epithelium. OSCC is often first diagnosed at late stages of the disease (advanced regional disease and/or metastasis). Delayed diagnosis precludes successful treatment and favorable outcomes. In clinical practice, opportunities exist to identify patients with oral potentially malignant disorders (OPMDs), which precede the development of cancer. This review addresses the current status of laboratory and clinical research on OPMDs, with emphasis on leukoplakia and erythroplakia. OSF is also presented, though there is a paucity of published studies on this disorder. We focus on findings that could translate into earlier diagnosis and more efficacious treatment of those lesions with significant malignant potential. We explore how markers of OPMD malignant transformation might be implemented into current diagnostic practice to help clinicians objectively stratify patients into treatment/follow-up groups according to relative risk. We provide an overview of recently concluded and ongoing OPMD chemoprevention trials. We describe laboratory OPMD models that can be used to not only to reveal the genetic and molecular intricacies of oral cancer but also to develop novel screening methods and therapeutic approaches. Finally, we call for targeted screening programs of at-risk populations in order to facilitate diagnosis and treatment of OPMD and early OSCC.

Advances in optical adjunctive AIDS for visualisation and detection of oral malignant and potentially malignant lesions

Traditional methods of screening for oral potentially malignant disorders and oral malignancies involve a conventional oral examination with digital palpation. Evidence indicates that conventional examination is a poor discriminator of oral mucosal lesions. A number of optical aids have been developed to assist the clinician to detect oral mucosal abnormalities and to differentiate benign lesions from sinister pathology. This paper discusses advances in optical technologies designed for the detection of oral mucosal abnormalities. The literature regarding such devices, VELscope and Identafi, is critically analysed, and the novel use of Narrow Band Imaging within the oral cavity is also discussed. Optical aids are effective in assisting with the detection of oral mucosal abnormalities; however, further research is required to evaluate the usefulness of these devices in differentiating benign lesions from potentially malignant and malignant lesions.