FLUORESCENCE IMAGING AND SPECTROSCOPY OF 5-AMINOLEVULINIC ACID-INDUCED PROTOPORPHYRIN-IX FOR THE DETECTION OF NEOPLASTIC LESIONS IN THE ORAL CAVITY

BACKGROUND: Semiquantitative fluorescence measurements following topic al application of 5-aminolevulinic acid (5-ALA) in 16 patients with ne oplastic lesions of the oral cavity were performed. METHODS: Time cour se and type of porphyrin accumulation were analyzed in neoplastic and surrounding healthy tissue by measuring emission spectra of 5-ALA-indu ced protoporphyrin IX fluorescence, Fluorescence images in the red and green spectral range from the tumor tissue were recorded with a charg e-coupled device camera. RESULTS: Protoporphyrin IX fluorescence was d etected in the oral mucosa of all patients after local application of 5-ALA. Protoporphyrin IX in neoplastic tissue accumulated earlier in c omparison with the surrounding normal tissue. The maximum fluorescence contrast of 10:1 between tumor and host tissue was generally seen 1-2 hours after application, allowing a demarcation of tumor tissue even with the naked eye. CONCLUSION: Labeling of mucosal lesions of the ora l cavity with Protoporphyrin IX fluorescence induced by the local appl ication of 5-ALA seems to be a promising diagnostic procedure for neop lastic lesions that are difficult to visualize under white light exami nation. It is the aim of further investigations to evaluate the releva nce of this new diagnostic procedure as a noninvasive and sensitive me thod for patients with oral cancer. (C) 1996 by Excerpta Medica, Inc.