Ex vivo high-definition optical coherence tomography of basal cell carcinoma compared to frozen-section histology in micrographic surgery: a pilot study

Background Micrographic surgery is an established, but time-consuming operating procedure for facial basal cell carcinoma (BCC). A new high-definition (HD) optical coherence tomography (OCT) with high lateral and axial resolution in a horizontal (en-face) and vertical (slice) imaging mode allows a fast and non-invasive in vivo examination of BCC. Objectives To compare the diagnosis of BCC in excised tissue ex vivo by high-definition optical coherence tomography (HD-OCT) with the findings of frozen-section histology in micrographic surgery. Methods Twenty freshly excised BCC were examined by HD-OCT in the en-face and slice imaging mode divided into four sections each in concordance with the four excision margins of histography, and subsequently processed for conventional micrographic evaluation. Results A total of 80 HD-OCT images of 20 BCCs were evaluated and in 45% (9/20) HD-OCT correlated perfectly with the histography results. The sensitivity and specificity for the 80 evaluated HD-OCT images were 74% and 64% respectively. Conclusions High-definition optical coherence tomography allows the postoperative identification of BCC in excised tissue ex vivo, but has still limitations in the recognition of tumour margins in comparison with the micrographic evaluation of frozen sections.