Toluidine blue color perception in identification of oral mucosal lesions

Diagnostic Accuracy of Toluidine Blue Electrospun in Detecting Oral Potentially Malignant Disorders

OBJECTIVE

Oral potentially malignant disorders (OPMDs) with epithelial dysplasia can progress to oral squamous cell carcinoma (OSCC). Toluidine blue (TB) has been used in oral screening with various methods. This study aimed to evaluate the sensitivity and specificity of TB-containing electrospun fibers in detecting OPMDs with epithelial dysplasia compared to histopathology.

METHODS

The concentrations of polyvinylpyrrolidone (PVP) and TB were optimized for fiber diameter and puncture strength using the design of experiments method with a central composite design. These optimized fibers were tested on 36 suspected OPMD lesions in 30 patients, followed by a biopsy for histopathological examination.

RESULTS

The quadratic and two-factor interaction models described the relationship between TB and PVP concentrations and fiber characteristics. The TB-containing electrospun fibers had 77.3% sensitivity and 35.7% specificity in detecting OPMDs with epithelial dysplasia.

CONCLUSION

The TB-containing electrospun fibers offer advantages such as easy application, cost-effectiveness, and enhanced sensitivity in identifying OPMDs with epithelial dysplasia. However, their diagnostic accuracy is insufficient as a standalone diagnostic method, and they should be considered an adjunctive tool for detecting dysplastic changes in the oral epithelium.

TRIAL REGISTRATION

Thailand Clinical Trials Registry: TCTR20240429002.

Recommendations for Research to Develop a Patient-Centered Clinical Follow-Up Protocol for Oral Epithelial Dysplasia

Oral epithelial dysplasia (OED) is the primary histological marker for assessing the progression of oral potentially malignant disorders (OPMDs) to cancer. Despite challenges in grading and low inter-pathologist reproducibility, OED severity remains the key predictor of malignant transformation. However, globally accepted guidelines for OED monitoring are lacking, despite calls for individualized management based on host and lesion characteristics. The proposed research protocol involves acquiring high-quality intraoral images, assessing oral hygiene and periodontal status, eliminating chronic mechanical irritation and Candida infections, and applying adjunctive diagnostic methods like toluidine blue staining, optical evaluation, and brush cytology. Tailored follow-up regimens based on individual risk assessments are emphasized, with frequent monitoring for high-grade dysplasia or patients at higher risk of progression. Therefore, effective OED management should consider the patient's immune status, dietary habits, and oral microbiota, aiming to develop personalized treatment strategies that optimize patient-centered care.

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.

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

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

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.

Current Practice and Emerging Molecular Imaging Technologies in Oral Cancer Screening

Oral cancer is one of the most common cancers globally. Survival rates for patients are directly correlated with stage of diagnosis; despite this knowledge, 60% of individuals are presenting with late-stage disease. Currently, the initial evaluation of a questionable lesion is performed by a conventional visual examination with white light. If a lesion is deemed suspicious, a biopsy is taken for diagnosis. However, not all lesions present suspicious under visual white light examination, and there is limited specificity in differentiating between benign and malignant transformations. Several vital dyes, light-based detection systems, and cytology evaluation methods have been formulated to aid in the visualization process, but their lack of specific biomarkers resulted in high false-positive rates and thus limits their reliability as screening and guidance tools. In this review, we will analyze the current methodologies and demonstrate the need for specific intraoral imaging agents to aid in screening and diagnosis to identify patients earlier. Several novel molecular imaging agents will be presented as, by result of their molecular targeting, they aim to have high specificity for tumor pathways and can support in identifying dysplastic/cancerous lesions and guiding visualization of biopsy sites. Imaging agents that are easy to use, inexpensive, noninvasive, and specific can be utilized to increase the number of patients who are screened and monitored in a variety of different environments, with the ultimate goal of increasing early detection.

Inter-and intra-observer agreement on the judgment of toluidine blue staining for screening of oral potentially malignant disorders and oral cancer

OBJECTIVE

Toluidine blue staining (TBS) is used for screening of oral potentially malignant disorders (OPMDs) and oral cancer. Nevertheless, the judgment of TBS is based on the observer's personal experience and largely considered subjective. The aim of this study was to evaluate the inter- and intra-observer agreement on the judgment of TBS for screening of OPMDs and oral cancer.

MATERIALS AND METHODS

Two hundred randomly ordered TBS images of OPMDs and oral cancer were judged twice independently by four clinicians and four graduated students majored in oral medicine, with an interval of 3 months. Inter- and intra-observer agreement was evaluated by the Cohen's kappa (κ) coefficient. The correlation between κ-value and individual experience was assessed by Spearman's correlation coefficient.

RESULTS

For the two sets of observation, good overall inter-observer agreement was found in the study (κ = 0.620 and 0.667). Sub-group analysis yielded good inter-observer agreement both for clinicians (κ = 0.613 and 0.611) and students (κ = 0.610 and 0.665). Pairwise inter-observer agreement was presented to be moderate to excellent between clinician and clinician (κ = 0.41~0.87, 0.43~0.81), moderate to excellent between student and student (κ = 0.43~0.71, 0.53~0.82), and poor to excellent between clinician and student (κ = 0.25~0.81, 0.35~0.87). Good to excellent intra-observer agreement (κ = 0.69~0.85) was presented for eight observers. However, no correlation was illustrated between years of experience and inter- or intra-observer agreement.

CONCLUSION

Judgment of TBS has a good overall inter-observer agreement and good to excellent intra-observer agreement, which guarantees its utilization and popularity in detecting OPMDs and oral cancer.

CLINICAL RELEVANCE

To our knowledge, this is the first study to investigate the inter- and intra-observer agreement of TBS judgment. The present results revealed a good inter-observer agreement and good to excellent intra-observer agreement, which provide a beneficial supplement to the knowledge of TBS technique.

Comparative efficacy of chemiluminescence and toluidine blue in the detection of potentially malignant and malignant disorders of the oral cavity

Context:

Early detection of oral cancer is of paramount importance in determining the prognosis of oral cancer. Literature suggests that several diagnostic modalities have been proposed to aid a clinician in early detection of oral cancer without much conclusive evidence.

Aims:

The present study aims to compare toluidine blue and chemiluminescence screening methods in early detection of carcinoma in North Indian population and also to evaluate these methods with histopathological diagnosis.

Methods:

In this prospective study, 42 patients with clinically visible premalignant lesions were included. Demographic data were collected, and suspicious lesions were examined by chemiluminescence light (Vizilite) and followed by local application of toluidine blue (Mashberg's recommendation). Findings were recorded for each lesion under standard incandescent light as positive or negative. Biopsy and histopathological analysis of the tissues were performed.

Statistical Analysis:

Sensitivity, specificity and positive and negative predictive values for the chemiluminescence technique and toluidine blue were calculated for diagnostic tests.

Results and Conclusions:

In the present study, toluidine blue test was found to be moderately sensitive (63.33%) whereas chemiluminescence test (Vizilite) was found to be highly sensitive (90%); however, the test has limited specificity (50%). Thus, the study concluded that both toluidine blue and Vizilite can be used as an adjunct to simple, conventional visual examination and in screening procedure for oral potentially malignant disorders.

Advances toward fully automated in vivo assessment of oral epithelial dysplasia by nuclear endomicroscopy-A pilot study

BACKGROUND

Uncertainties in detection of oral epithelial dysplasia (OED) frequently result from sampling error especially in inflammatory oral lesions. Endomicroscopy allows non-invasive, "en face" imaging of upper oral epithelium, but parameters of OED are unknown.

METHODS

Mucosal nuclei were imaged in 34 toluidine blue-stained oral lesions with a commercial endomicroscopy. Histopathological diagnosis showed four biopsies in "dys-/neoplastic," 23 in "inflammatory," and seven in "others" disease groups. Strength of different assessment strategies of nuclear scoring, nuclear count, and automated nuclear analysis were measured by area under ROC curve (AUC) to identify histopathological "dys-/neoplastic" group. Nuclear objects from automated image analysis were visually corrected.

RESULTS

Best-performing parameters of nuclear-to-image ratios were the count of large nuclei (AUC=0.986) and 6-nearest neighborhood relation (AUC=0.896), and best parameters of nuclear polymorphism were the count of atypical nuclei (AUC=0.996) and compactness of nuclei (AUC=0.922). Excluding low-grade OED, nuclear scoring and count reached 100% sensitivity and 98% specificity for detection of dys-/neoplastic lesions. In automated analysis, combination of parameters enhanced diagnostic strength. Sensitivity of 100% and specificity of 87% were seen for distances of 6-nearest neighbors and aspect ratios even in uncorrected objects. Correction improved measures of nuclear polymorphism only. The hue of background color was stronger than nuclear density (AUC=0.779 vs 0.687) to detect dys-/neoplastic group indicating that macroscopic aspect is biased.

CONCLUSIONS

Nuclear-to-image ratios are applicable for automated optical in vivo diagnostics for oral potentially malignant disorders. Nuclear endomicroscopy may promote non-invasive, early detection of dys-/neoplastic lesions by reducing sampling error.

Toluidine blue aids in detection of dysplasia and carcinoma in suspicious oral lesions

OBJECTIVES

Accurate clinical identification of 'higher-risk' oral premalignant lesions or 'higher-risk' areas within lesions is important. Assessment methods that predict their presence have great utility.

SUBJECTS AND METHODS

A cross-sectional, observational study enrolled a consecutive sample of consenting patients diagnosed with oral leukoplakia, erythroleukoplakia, or erythroplakia. Medical history, visual oral examination, ViziLite(®) examination, toluidine blue staining (TBlue(®) ), and finally a biopsy were completed in a single clinic visit. Seventy-seven of 100 examined lesions in 43 patients were biopsied. Sensitivity, specificity, and positive and negative predictive values were computed for visual examination, ViziLite(®) , and TBlue(®) using biopsy results as the gold standard.

RESULTS

The sensitivity of TBlue(®) in detecting high-risk lesions (carcinoma in situ or carcinoma) was 94 (71-100, P < 0.0003) and specificity 45 (32-58, P < 0.53), while for carcinoma, sensitivity was 100 (54-100, P < 0.032) and specificity 39 (28-52, P < 0.097). The results of ViziLite(®) testing either by itself or in combination with the information from toluidine blue testing revealed low sensitivity for the detection of high-risk lesions.

CONCLUSIONS

Clinical examination of leukoplakia, erythroplakia, or erythroleukoplakia lesions combined with toluidine blue staining may aid in the identification of severe dysplasia (carcinoma in situ) or carcinoma. This may help in determining whether, when, and where (the site within a lesion) a biopsy should be taken.

An update on intraoral application of colposcopy

Colposcopy is an established technique for diagnosis in gynecology. Many premalignant and malignant lesions in these areas have discernible characteristics which can be detected using a colposcope, providing an enlarged view of the areas, allowing the colposcopist to visually distinguish normal from abnormal appearing tissue and take directed biopsies for further pathological examination. The diagnosis of a dysplastic lesion of the oral mucosa cannot be based solely on clinical findings. Therefore, histological evaluation of a representative biopsy specimen is necessary. The site for the biopsy is a subjective choice that sometimes raises doubts about its representativeness. So far, no simple and reliable method is available for selecting the most appropriate area for biopsy. Intraoral microscopy (oral application of the colposcopy technique) of mucosal lesions seems to offer advantages in selecting more representative sites for biopsy than routine clinical examination alone. The biopsy sites identified by direct oral microscopy show more advanced histologic signs than those selected by routine clinical examination. This article enlightens the application of colposcopy in diagnosis of oral premalignant lesions and malignant lesions.

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.

A chemiluminescent light system in combination with toluidine blue to assess suspicious oral lesions-clinical evaluation and review of the literature

OBJECTIVES

The aim of the study was an evaluation of an acetic acid wash and chemiluminescent light system in combination with toluidine blue in order to detect visual identified, potentially malignant lesions.

MATERIALS AND METHODS

Forty-four patients with 50 oral lesions of primary uncertain visible dignity were included. Next to a clinical examination, a screening with ViziLite® (VL) as well as toluidine blue (TB; together ViziLite® Plus (VLP)) was conducted. Histopathology served as gold standard and sensitivity (SE), specificity (SP), positive as well as negative predictive value (PPV, NPV) was calculated descriptively. Additionally, a PubMed literature search using the key words "ViziLite" and "chemiluminescence oral cancer" was conducted.

RESULTS

Histological diagnosis showed 40 lesions of reactive/inflammatory nature, moderate dysplasia (n = 3) and oral squamous cell carcinoma (OSCC n = 7). All OSCCs and one dysplasia were identified correct via clinical diagnosis (SE 90 %, SP 100 %, PPV 100 %, NPV 97.5 %). VL examination could show all malignancies with low specificity (SE 100 %, SP 30 %, PPV 26 %, NPV 100 %). TB and VLP were positive in all cases of cancer and in one case of inflammation (SE 80 %, SP 97.5 %, PPV 89 %, NPV 95 %). In the review, eight clinical trials with similar results were included.

CONCLUSIONS

The adjunct of TB to VL reduces the number of false positives without increasing the rate of false negatives.

CLINICAL RELEVANCE

Clinical evidence to justify the additional cost of the system for diagnosis of suspicious lesions is weak. However, for the potential role of VLP in detection of lesions not otherwise identified in the visual exam in general dental practice further studies are required.

Saliva as a diagnostic fluid

Salivary diagnostics is a dynamic and emerging field utilizing nanotechnology and molecular diagnostics to aid in the diagnosis of oral and systemic diseases. In this article the author critically reviews the latest advances using oral biomarkers for disease detection. The use of oral fluids is broadening perspectives in clinical diagnosis, disease monitoring, and decision making for patient care. Important elements determining the future possibilities and challenges in this field are also discussed.

Effectiveness of autofluorescence to identify suspicious oral lesions--a prospective, blinded clinical trial

Regular screening through white light inspection of the entire oral mucosa is the most important examination method to identify precancerous lesions and early oral carcinoma. Additionally, the physiologic autofluorescence of the oral mucosa has been described as a novel screening method for the detection of mucosal lesions that are not visible by white light. This study aimed to evaluate the sensitivity and specificity of the autofluorescence examination. Seventy-eight patients were examined in this study. All of them suffered from suspicious oral mucosal lesions. Two different investigation methods were applied: the standard examination by white light and an examination by a novel light source of 400 nm that evoked a green light emission (>500 nm) in normal mucosa. It was proposed that malignant oral mucosal lesions show different autofluorescence characteristics than the green autofluorescence of healthy mucosa. Red autofluorescence indicated SCC with a sensitivity of 20% and a specificity of 98%. The results showed that dysplasia and carcinoma could be identified with a sensitivity of 96% and a specificity of 18% by using the autofluorescence method. The sensitivity decreased according to the grade of mucosal keratosis and was influenced by the localisation of the lesion. In conclusion, benign as well as malignant oral lesions could not be distinguished by a diminished autofluorescence signal. A red autofluorescence signal, however, could indicate cancerous processes of the oral mucosa.