Optical Imaging in the Diagnosis of OPMDs Malignant Transformation

Abstract

Oral potentially malignant disorders (OPMDs) are a heterogeneous group of oral lesions with a variable risk of malignant transformation to oral squamous cell carcinoma. The current OPMDs malignant transformation screening depends on conventional oral examination (COE) and is confirmed by biopsy and histologic examination. However, early malignant lesions with subtle mucosal changes are easily unnoticed by COE based on visual inspection and palpation. Optical techniques have been used to determine the biological structure, composition, and function of cells and tissues noninvasively by analyzing the changes in their optical properties. The oral epithelium and stroma undergo persistent structural, functional, and biochemical alterations during malignant transformation, leading to variations in optical tissue properties; optical techniques are thus powerful tools for detecting OPMDs malignant transformation. The optical imaging methods already used to detect OPMDs malignant transformation in vivo include autofluorescence imaging, narrowband imaging, confocal reflectance microscopy, and optical coherence tomography. They exhibit advantages over COE in detecting biochemical or morphologic changes at the molecular or cellular level in vivo; however, limitations also exist. This article comprehensively reviews the various real-time in vivo optical imaging methods used in the adjunctive diagnosis of OPMDs malignant transformation. We focus on the principles of these techniques, review their clinical application, and compare and summarize their advantages and disadvantages. Finally, we conclude with a discussion of current challenges and future directions of this field.

Efficacy of optical coherence tomography in the diagnosing of oral cancerous lesion: systematic review and meta‐analysis

“…Also, as the tissue changes from normal to premalignant, the squamous epithelium tends to thicken 29 . OCT can identify epithelial stratification, as well as structural and thickness changes through high‐resolution epithelial and subepithelial images; our results are consistent with recent studies 21,31 . OCT may be useful in clinical practice to identify the optimal biopsy site, follow up lesions, and identify high‐risk groups 28 …”

“…Since then, numerous investigations of the diagnostic accuracy of OCT for distinguishing oral cancerous lesions have been performed. Review articles have also summarized studies showing the efficacy of OCT for differentiating malignant tumors from benign and inflammatory mucosal lesions 30,31 . However, since no meta‐analysis has analyzed the diagnostic power of OCT for OPMLs or oral cancer lesions, we performed the present bivariate meta‐analysis.…”

“…In addition, AI can provide quantitative data to aid clinical decision‐making, by transforming diagnostic images with unclear margins. With sufficient data sets and algorithms, the diagnostic accuracy of AI could be similar, or even exceed, that of clinical experts 31 …”

“…Therefore, in vivo studies are needed to verify our results. Third, mechanical compression of the mucosa by the OCT probe may have affect the results, by decreasing tissue thickness or increasing contrast between layers, for example 31,36 …”

“…Review articles have also summarized studies showing the efficacy of OCT for differentiating malignant tumors from benign and inflammatory mucosal lesions. 30,31 However, since no meta-analysis has analyzed the diagnostic power of OCT for OPMLs or oral cancer lesions, we performed the present bivariate meta-analysis. In addition, qualitative and quantitative OCT data may vary depending on the diagnostic category, and results may differ depending on whether the judgment is made by a trained clinician, automated algorithm, or AI.…”