Photodynamic detection in visualisation of cutaneous and oral mucosapremalignant and malignant lesions - two clinical cases

摘要

Photodynamic diagnosis (PDD) is promising method of visualisation of premalignant and malignant lesions. PDD isconsisted of two main agents: special chemical compound which is called photosensitizer and light. Photosensitizer hasaffinity to fast proliferating cells such as pre- or malignant. During light irradiation (with proper wavelength –corresponding to absorption peak of photosensitizer) photosensitizer gains energy and passes into excited singlet state S_1 .Returning to basic singlet state S_n, leads to fluorescence. Due difference between concentration of photosensitizer inlesion and normal tissue it is possible to obtain high contrast image of lesion. Case #1: 53 years old woman with basal cell carcinoma (BCC) in nasal region; 20% delta-aminolevulinic acid as aprecursor of photosensitizer on eucerin base was used.Case #2: 57 years old woman with multifocal oral leukoplakia on cheek mucosa and tongue; 2% chlorophyll gel asphotosesitizer was used. All photographs were taken in white light without any filter and in blue and UV light with orange filter: in both cases thetotal area of the lesions appeared to be larger than it has been clinically observed. Thus, the PDD might be helpful inevaluation of margins of surgical excision of such lesions.