Preoperative assessment of basal cell carcinoma using conventional fluorescence diagnosis

Abstract

Fluorescence diagnosis (FD) seems to be a promising method for the non-invasive detection of tumour boundaries. We aimed to investigate the diagnostic performance of conventional FD of basal cell carcinoma (BCC). Patients were included in this study when they had a skin lesion on the head which was clinically consistent with the diagnosis of BCC. FD was performed using a 20% 5-aminolaevulinic acid (ALA) cream. The FD tumour area was determined 3.5 h after the ALA application using the naked eye and a Wood lamp. The tumour margins were marked on the basis of FD. The lesions were then excised according to the FD-defined tumour margin. On histology, the tumour margins were checked whether the lesion was completely excised in accordance with FD. Twenty-eight BCCs were finally included into the statistical analysis. In six BCCs, the FD-defined BCC margin did not correlate with the histopathologically assessed tumour borders. Four of these lesions were incompletely excised; two tumours were excised in toto indicating that the tumour was beyond the FD-defined margin but not at the excision margin. Hence, the rate of incompletely excised BCCs was 14.3% (4/28). The sensitivity and specificity rates of FD were 79 and 100%, respectively. FD is pretty sensitive and highly specific in regard to the demarcation of BCC margins. When compared to clinically based BCC excision, however, FD does not appear to be substantially superior to simple clinical assessment of tumour margins.