Optical coherence tomography for diagnosing recurrent or residual basal cell carcinoma after topical treatment: A diagnostic cohort study.

Abstract

Recurrent/residual basal cell carcinoma (BCC) after topical treatment may not be visible during clinical and dermatoscopic examination (CDE). Optical coherence tomography (OCT) may detect these subclinical recurrences or residues. To compare the diagnostic accuracy of CDE with that of CDE combined with OCT (CDE-OCT) for detecting recurrent/residual BCC after topical treatment of superficial BCC. In this diagnostic cohort study, the suspicion level for recurrence or residue was recorded on a 5-point confidence scale. All patients with high suspicion of recurrence or residue based on CDE and/or CDE-OCT were referred for punch biopsy. Patients with a low suspicion on CDE and CDE-OCT were asked to (voluntarily) undergo a control biopsy. Histopathologic results of the biopsy were used for verification of CDE and CDE-OCT diagnoses (gold standard). This study included 100 patients. A histopathologic recurrent/residual BCC was found in 20 patients. For recurrence or residue detection, sensitivity was 100% (20 of 20) for CDE-OCT and 60% (12 of 20) for CDE (P = .005) and specificity was 95% for CDE-OCT and 96.3% for CDE (P = .317). The area under the curve for CDE-OCT (0.98) was significantly higher than that for CDE (0.77) (P = .001). Results are based on 2 OCT assessors. Compared with CDE alone, CDE-OCT results in a significantly higher ability to detect recurrent/residual BCCs after topical treatment.