Treatment of oral leukoplakia by topical application of 5-aminolevulinic acid

A new therapy for the treatment of oral leukoplakia by 5-aminolevulinic aci d (ALA) and photodynamic therapy (PDT) is presented. ALA, a precursor in th e biosynthesis of haeme, induces the production of the endogenous photosens itizer protoporphyrin IX which can be used for PDT. Twelve patients, who ha d been suffering from leukoplakia of the oral mucosa for several years, wer e treated by ALA-mediated PDT ALA was used as a topical photosensitizer and 20% ALA cream was applied to the leukoplakia lesion of the oral mucosa for two hours and then light activated at 630 nm, 100 mW/cm(2) and 100 J/cm(2) . Five patients showed complete response to the treatment, four patients sh owed a partial response and in three patients treatment was unsuccessful. O ne patient with partial response was retreated, after which the lesion disa ppeared.