A POSSIBLE NEW INCOHERENT LAMP FOR PHOTODYNAMIC TREATMENT OF SUPERFICIAL SKIN-LESIONS

Since coherence of laser light is not necessary for photodynamic thera py of skin lesions, attempts have been made to construct incoherent la mps. A recent development is the PDT 1200 (Waldmann Medizintechnik/Ger many), a light source consisting of a 1200 watt metal halogen lamp. Em ission of 600 to 800 nm radiation is achieved by using cut-off filters . Power density can be varied from 30 mW/cm2 to 200 mW/cm2 in an area from 100 to 300 cm2. Biological effectiveness was proved by comparison with the radiation of an argon-pumped dye laser (Kiton red) emitting light at 630 nm. Three human cell lines were incubated with photofrin at different concentrations. After irradiation, cell viability was tes ted (MTT assay). Results proved biological effectiveness of the light source PDT 1200. No significant difference in cell viability was detec ted using either concentration of sensitizer. Therefore, we believe th at PDT 1200 is a promising new light source for photodynamic therapy o f skin lesions.