In vivo differentiation of common basal cell carcinoma subtypes by microvascular and structural imaging using dynamic optical coherence tomography.

The subtype of basal cell carcinoma (BCC) influences the choice of treatment. Optical coherence tomography (OCT) is a non-invasive imaging tool, and a recent development of an angiographic version of OCT has extended the application of OCT to image the cutaneous microvasculature (so-called dynamic OCT, D-OCT). This study explores D-OCT's ability to differentiate the common BCC subtypes by microvascular and structural imaging. Eighty-one patients with 98 BCC lesions, consisting of three subtypes: 27 superficial BCC (sBCC), 55 nodular BCC (nBCC) and 16 infiltrative BCC (iBCC) were D-OCT scanned at three European dermatology centres. Blinded evaluations of microvascular and structural features were performed, followed by extensive statistical analysis of risk ratio (RR) and multiple correspondence analysis. nBCC lesions displayed most characteristic structural and vascular features. Serpiginous vessels, branching vessels, vessels creating a circumscribed figure and sharply demarcated hyporeflective ovoid structures in the dermis were all associated with a higher risk of the subtype being nBCC. The presence of highly present lines and dark peripheral borders at the margin of ovoid structures was negatively associated with iBCC. Lastly, the finding of hyporeflective ovoid structures protruding from epidermis correlated with sBCC. We identified various microvascular and structural D-OCT features that may aid non-invasive identification of BCC subtypes. This would allow clinicians to individualize and optimize BCC treatment as well as aid follow-up of non-surgical treatment.