The sensitivity and specificity of optical coherence tomography for the assisted diagnosis of nonpigmented basal cell carcinoma: An observational study

Summary Background The diagnostic criteria for basal cell carcinoma (BCC) using optical coherence tomography (OCT) have been described previously, but the clinical value of these findings remains unknown. Objectives To investigate the diagnostic value of OCT for BCC in a typical clinical setting. The primary efficacy end point was a diagnosis of BCC for each lesion. Secondary end points were the diagnosis of other possible conditions. Methods This was an observational, prospective, multicentre study in which consecutive patients with nonpigmented pink lesions suspicious for BCC underwent clinical assessment, dermoscopy and OCT, with the diagnosis recorded at each stage. Once all diagnoses had been recorded, the histological results were disclosed. In total 164 patients with 256 lesions were recruited. Histology was missing for 21 lesions, leaving 235 lesions in 155 patients for analysis. Results Sixty per cent of lesions (141 of 235) were identified as BCC by histology. A slight increase of sensitivity was noted following OCT, which did not reach statistical significance. The specificity increased significantly from 28·6% by clinical assessment to 54·3% using dermoscopy and to 75·3% with the addition of OCT (P < 0·001). The positive predictive value for the diagnosis of BCC using OCT was 85·2% [95% confidence interval (CI) 78·6-90·4], and the negative predictive value was 92·1% (95% CI 83·6-97·0). The accuracy of diagnosis for all lesions increased from 65·8% with clinical evaluation to 76·2% following additional dermoscopy and to 87·4% with the addition of OCT. Conclusions OCT significantly improved the diagnostic specificity for BCC compared with clinical assessment and dermoscopy alone. What's already known about this topic? The diagnostic criteria of basal cell carcinoma (BCC) by optical coherence tomography (OCT) have previously been defined. Recent studies have also described the OCT criteria of actinic keratoses. What does this study add? The results of this study support the additional diagnostic value of OCT for the diagnosis of pink patches. The diagnostic specificity for BCC may be increased by the use of OCT.