Optical coherence tomography in the assessment of suspicious oral lesions: an immediate ex vivo study

Background: Optical coherence tomography (OCT) is an evolving optical technology that is capable of delivering real-time, high-resolution signatures of tissue.

Objectives: The purpose of this immediate ex vivo prospective clinical study was: (1) to assess the sensitivity and specificity of OCT on biopsy material in identifying potentially malignant and malignant oral lesions, (2) to determine the inter-observer agreement in the analysis of specific image parameters, and (3) to find out the oral epithelial thickness for different pathology groups.

Materials and methods: This prospective study involved 125 suspicious oral lesions from 125 patients. The lesions were surgically biopsied and subjected to OCT in the immediate ex vivo phase. Two independent readers (surgeon and pathologist) examined the OCT images and assessed several cellular features including keratin layer, epithelial layer, basement membrane and lamina propria, and recorded their findings using special OCT reading score. The sensitivity, specificity and accuracy of OCT to predict "the future need for surgical biopsy in case of any similar lesion" were calculated. The epithelial thickness was also measured. The degree of agreement between the two readers was recorded.

Results: The pathological diagnosis revealed that the majority of lesions demonstrated microinvasive carcinomas (n=43). Forty-one had different degree of dysplasia. Benign oral lesions were less common and included 22 keratosis, 11 non-specific lesions, 6 mucocels and 2 papillomas. Optical coherence tomography achieved a sensitivity of 85% and a specificity of 78% in the assessment of oral potentially malignant and malignant disorders. The positive and negative predictive values were 86.5% and 77.5%, respectively. The accuracy was 82% and the kappa coefficient of inter-observer agreement was 0.72 on "the need for biopsy". OCT imaging of oral lesions provided valuable information on the oral epithelial thickness.

Conclusion: This study proposes that OCT can accurately identify wide spectrum of oral tissue pathologies. Further studies can assess the role of OCT in evaluating and guiding surgical biopsies and monitoring disease.