The utility of optical coherence tomography for diagnosis of basal cell carcinoma: a quantitative review

BackgroundOptical coherence tomography (OCT) is a noninvasive near-infrared light imaging technology that can be utilized to diagnose basal cell carcinomas (BCCs) based on specific morphological features. ObjectivesTo conduct a quantitative review using tumour-level data from published studies to assess: (i) the in vivo diagnostic accuracy of different OCT systems; (ii) correlation between OCT features and histopathological diagnosis; and (iii) factors that impact the accuracy of tumour depth estimation. MethodsPrimary tumour-level data were extracted from published studies on the use of time-domain (TD-OCT), frequency-domain (FD-OCT) and high-definition (HD-OCT) systems for diagnosis of BCCs. Quality assessment was performed using the Newcastle-Ottawa Scale and the Cochrane Risk of Bias Tool. Sensitivity and specificity for diagnosis of BCC, prevalence of morphological features and correlation of tumour depth between OCT and histopathology were analysed. ResultsIn total, 901 BCCs from 31 studies were included. The sensitivity and specificity were 893% and 603% overall, and were highest for FD-OCT (937% and 614%, respectively). The most prevalent morphological features were lobular pattern (802%, 315 of 393 tumours) and hyper-reflective peritumoral stroma (517%, 203 of 393). Concordance between OCT and histopathological tumour depth categories was moderate (Pearson coefficient 048); it was highest for tumours < 1 mm and those on the extremities. The overall bias was 0075 mm with an agreement range from -088 to 103 mm. HD-OCT and FD-OCT were superior to TD-OCT at identifying morphological features, but not at tumour depth estimation. ConclusionsOCT is a viable tool for in vivo diagnosis of BCCs. FD-OCT and HD-OCT outperformed TD-OCT in diagnostic accuracy and detection of morphological features, but not tumour depth estimation. What's already known about this topic? Optical coherence tomography (OCT) is a noninvasive imaging modality that can be used to diagnose basal cell carcinoma (BCC). Morphological features found on OCT images correlate with specific histopathological findings. OCT can also detect subclinical extension of tumours and improve preoperative delineation of surgical margins. What does this study add? This study analysed tumour-level data from 31 published studies encompassing 901 BCCs. We calculated the diagnostic sensitivity and specificity of different OCT systems, determined the degree of correlation between OCT morphological features and BCC diagnosis and analysed tumour and machine factors that affect OCT estimation of tumour depth. Linked Comment: Navarrete-Dechent et al. Br J Dermatol 2019; 180:448-449. Plain language summary available online