BACKGROUND AND OBJECTIVE: The diagnosis of precancerous and cancerous skin lessons in pretreated or scarred skin can be difficult. The determination of the right biopsy site in a suspected area depends largely on the physician's experience. PATIENTS/ METHODS: The possibility of using a CCD-camera system and measuring 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 intensity was achieved by means of the described optical system and digital imaging. The contrast of the acquired fluorescence images can be significantly enhanced and allows the determination of a threshold. As result an initial, clinically not visible basal cell carcinoma was detected and excised by a punch 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.
BACKGROUND AND OBJECTIVE: The diagnosis of precancerous and cancerous skin lessons in pretreated or scarred skin can be difficult. The determination of the right biopsy site in a suspected area depends largely on the physician's experience. PATIENTS/ METHODS: The possibility of using a CCD-camera system and measuring 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 intensity was achieved by means of the described optical system and digital imaging. The contrast of the acquired fluorescence images can be significantly enhanced and allows the determination of a threshold. As result an initial, clinically not visible basal cell carcinoma was detected and excised by a punch 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.