Fluorescence-directed biopsy of basal cell carcinomas

Background and Objective. The diagnosis of precancerous and cancerous skin leasons in pretreated or scarred skin can be difficult. The determination o f the right biopsy site in a suspected area depends largely on the physicia n's experience. Patients/Methods. The possibility of using a CCD-camera system and measurin g tumor fluorescence following topical application of 5-aminolevulinic acid was employed in a single case to facilitate accurate choice of biopsy site . Results. An user-independent evaluation of the induced fluorescence intensi ty was achieved by means of the described optical system and digital imagin g. The contrast of the acquired fluorescence images can be significantly en hanced and allows the determination of a threshold. As result an initial, c linically not visible basal cell carcinoma was detected and excised by a pu nch biopsy in toto. Conclusions. Using the described optical system the early recognition of a superficial basal cell carcinoma and the determination of the exact biopsy site was achieved in pretreated skin. The routine employment of the system will be assessed in a prospective study.