Light-based Detection Systems Research Articles

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

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. 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. 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). 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.

Comparing the efficacy of chemiluminescence with lugol's iodine versus toluidine blue in the diagnosis of dysplasia in tobacco associated oral lesions - A diagnostic study

Chemiluminescence is the production of light as a result of a chemical reaction. Oral potentially malignant disorders (OPMDs) include both precancerous lesions and conditions that carry an increased risk of cancer. There are different etiological and risk factors for OPMDs such as smoking, alcohol consumption, infections such as viral and fungal, sun exposure and certain other genetic factors. The most common etiological factor for OPMDs is tobacco usage. Chemiluminescence is a light-based detection system and is very useful for detecting OPMDs for early intervention. Because it is a non-invasive procedure, it can be used to evaluate dysplastic changes in various OPMDs at their initial stage for timely intervention. Vital staining has also been used as a chair-side marker for delineating normal and dysplastic oral mucosal tissues. To compare the efficacy of chemiluminescence with Lugol's iodine to that with toluidine blue in diagnosing dysplastic changes in tobacco associated oral lesions. A total of 84 patients with clinically suspicious oral mucosal lesions and OPMDs with tobacco habit history were included and randomly assigned to either of the diagnostic study groups (Group A: chemiluminescence with Lugol's iodine or Group B: chemiluminescence with toluidine blue). All these patients were subjected to a histopathological examination (reference standard). The sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and receiver operating characteristics (ROC) were 91.7%, 66.7%, 84.6%, 80%, and 0.792 for chemiluminescence with Lugol's iodine group (P = 0.001) respectively whereas for chemiluminescence with toluidine blue, the sensitivity, specificity, PPV, NPV and ROC were 100%, 60%, 93.3%, 100% and 0.800 (P = 0.002), respectively. The combination of chemiluminescence with toluidine blue had a better diagnostic efficiency in detecting dysplasia in tobacco-associated oral lesions when compared to the group of chemiluminescence with Lugol's iodine.

Use of X-ray Diffraction Technique of Hair for Oral Cancer Detection: A Proposal

Techniques that contribute to early diagnosis of oral potentially malignant disorders (OPMDs) and oral squamous cell carcinoma (OSCC) till now followed are vital staining, light-based detection systems along with various histological, cytological, molecular and imaging techniques.1 In spite of histopathological technique being the gold standard, diagnosis by taking random biopsies of both clinically normal and the suspected oral area is impractical, since various serious downsides are associated with it and are also not appropriate for repetitive sampling at multiple sites.2 A screening test which is non-invasive, safe without exposing an individual to X-radiation and more consistent than any other current method is direly required.

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.

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.

Non-Invasive Techniques for Detection and Diagnosis of Oral Potentially Malignant Disorders.

Oral squamous cell carcinoma (OSCC) is the most common oral and maxillofacial malignancy, and its morbidity and mortality rates are still high in most countries. Oral potentially malignant disorders (PMDs) are used to refer to a heterogeneous group of conditions that are characterized by increased risk for malignant transformation to OSCC. Currently identified oral PMDs include leukoplakia, erythroplakia, palatal lesions associated with reverse smoking, oral lichen planus, oral submucous fibrosis, actinic keratosis, and discoid lupus erythematosus. The early detection and diagnosis of these lesions are important for cancer prevention and disease management. In recent years, there has been a growing and persistent demand for new non-invasive, practical diagnostic techniques that might facilitate the early detection of oral PMDs. The non-invasive detection techniques evaluated in this review are divided into four categories: vital staining with a solution that can be used as a mouth rinse or applied onto a suspected area of the mouth, light-based detection systems, optical diagnostic technologies that employ returned optical signals to reflect structural and morphological changes within tissues, and salivary biomarkers. Most of these techniques have shown great potential for screening and monitoring oral PMDs. In this review article, the authors critically assess these non-invasive detection techniques for oral PMDs. We also provide a summary of the sensitivity and specificity of each technique in detecting oral PMDs and oral cancer, as well as their advantages, disadvantages, clinical applications, and indications.

‘Biologic endoscopy’: optimization of upper aerodigestive tract cancer evaluation

Endoscopy is the first-line examination and most reliable way to get precise bidimensional assessment of the superficial extent of a squamous cell cancer arising within the upper aerodigestive tract (UADT). Its role as the cornerstone at each diagnostic step in the evaluation of head and neck cancer patients, in both treatment and follow-up, cannot be overemphasized. A number of technological improvements have been introduced to enhance conventional white light endoscopy of the UADT, in order to provide deeper insight into the specific biological properties of observed lesions. The purpose of this review is to summarize the most recent trends in 'biologic endoscopy' techniques. Starting from the use of toluidine blue up to the most recent light-based detection systems such as autofluorescence and narrow band imaging, researchers have devoted substantial efforts to the identification of specific biological properties of neoplastic tissues that can be targeted by new endoscopic tools. These aids attempt to assist the surgeon in achieving a more reliable distinction between normal and neoplastic or precancerous mucosa, within a wide range of inflammatory and iatrogenic modifications. Even though direct comparison of the efficacy of these techniques is seldom feasible due to their site-specific application, different advantages and disadvantages, economic considerations, and limited diffusion in daily practice, it is nevertheless clear that the future of endoscopy of the UADT will be strongly influenced by these new technologies.

Enhanced chemiluminescence: a high-sensitivity detection system for in situ hybridization and immunohistochemistry.

The breakthrough of chemiluminescence in the field of solution immunoassays and transfer membranes prompted us to explore whether a light-based detection system could provide a gain in sensitivity over chromogenic and FITC markers for nucleic acid and protein detection on histological preparations. A Hamamatsu device and an enhanced chemiluminescence (ECL) luminol substrate of the peroxidase were used to detect epithelial and endothelial components by immunohistochemistry (IHC) and for in situ hybridization (ISH) of papilloma virus DNA. The accuracy of the signal was compared to that obtained with DAB-peroxidase, silver-enhanced DAB-peroxidase, NBT-BCIP-alkaline phosphatase, and FITC. Our results demonstrated the feasibility and high sensitivity of luminescence detection for histological preparations. In part due to the ultrasensitive videocamera and photon-counting imaging, interpretable and reproducible results were obtained within counting times shorter than 5 min, and with dilutions of the primary antibodies 100- to 10,000-fold greater than those used for chromogenic and FITC reactions. As for ISH, with identical concentrations of the HPV 18 DNA probe on HeLa cells, labeling was apparent by luminescence but undetectable with the chromogen. The morphological resolution allowed a discriminatory analysis of the signal. Therefore, at the light microscopic level, enhanced chemiluminescence offers an appealing alternative to FITC and chromogenic markers for detection and quantification of low-concentration molecules.