Skin and mucosal fluorescence diagnosis with different light sources

At the laboratory of Laser and Photodynamic Treatment (Institute of Oncology, Vilnius University) 98 patients with various kinds of skin and mucosal malignant, pre-malignant and benign lesions underwent 5-aminolevulinic acid (ALA) or its methyl ester (methyl aminolevulinate)-induced protoporphyrin IX (PpIX), or hematoporphyrin derivate (HpD) fluorescence imaging. Intensity and all other changes of fluorescence were evaluated and compared with the pathological findings. Margins of tumours were clearly outlined under fluorescent vision, giving a helpful contribution to diagnosis and therapy, even in clinically non-visible tumours. Most of the malignant tumours were found to be fluorescent, whereas no fluorescence was observed in normal skin and mucosa. In the blue light mode, there is background blue fluorescence in normal tissue and red fluorescence in malignant areas. The suitability of different light wavelengths for fluorescence diagnosis (FD) was compared. From our data the most appropriate wavelength for this purpose is 401 nm.