Optical Coherence Tomography for Noninvasive Diagnosis and Subtyping of Basal Cell Carcinoma: A Prospective Cohort Study

Noninvasive diagnostic strategies such as optical coherence tomography (OCT) enable detailed examination of skin tissue architecture and have potential for identification and subtyping of basal cell carcinoma (BCC). To evaluate the additional diagnostic value of OCT, a prospective cohort study was performed in 182 patients with 250 lesions suspected for non-melanoma skin premalignancies requiring a biopsy. Accuracy of BCC diagnosis and subtype on the basis of clinical examination (CE) of patients was compared with that on the basis of OCT scans in conjunction with clinical images of lesions (cOCT). Confidence levels were recorded on a 5-point scale, where score 0 indicated absence of BCC and scores 1-4 indicated increasing suspicion of BCC. Diagnostic performance parameters were compared using histopathologic diagnosis as gold standard. The patient-based area under the receiver operating characteristic curve (AUC) increased from 85.6% for CE to 91.2% for cOCT (P = 0.061) and the lesion-based AUC from 82.7% to 91.3% (P <0.001). When confidence scores 1-4 were defined as positive, patient-based specificity increased from 47.5% (CE alone) to 76.8% (cOCT) at similar sensitivity (97.6% and 95.2%, respectively). cOCT slightly improved the ability to discriminate between superficial and nonsuperficial BCC subtypes and seemed to be a valuable addition to CE alone in the diagnosis and subtyping of BCC.