Abstract

Fluorescence imaging has shown a potential for demarcation of basal cell carcinoma (BCC), which is the most common type of skin cancer. The technique is based on imaging the fluorescence from protoporphyrin IX (Pp IX), after application of δ-5-aminolevulinic acid (ALA). One limitation with the technique is that it is sensitive for undesired local intensity variations. But it has been shown that by combining autofluorescence, i.e. fluorescence without any externally applied photosensitiser, and the Pp IX fluorescence, higher contrast between tumour and normal skin can be obtained. This has earlier been reported using a laser-based technique allowing for simultaneous recording of autofluorescence and Pp IX fluorescence. In this work we present a method, using a simple set up for multispectral imaging assisted by computerised image warping. The set up was evaluated investigating 9 patients with histologically verified BCC located in the face. Z-images, defined as the ratio between the autofluorescence and the Pp IX fluorescence images, were obtained and compared to the clinically marked tumour borders. Agreement with the tumour border was found in 8 out of the 9 patients. These results imply that multispectral fluorescence imaging is a potential diagnostic tool for demarcation of BCC.

© 2003 SPIE