Influence of light irradiation on blood oxygen saturation level in vitro and in vivo during photodynamic therapy

摘要

Photodynamic therapy (PDT) is an effective method to treat cancer and other nononcological lesions by means of light action on photosensitizer in tissue. It is assumed that the destroying effect is mainly due to the formation of singlet oxygen resulting from the interaction of light excited photosensitizer with molecular oxygen (triplet ground state). So the destroying effect will be proportional to the rate of singlet oxygen formation which in turn depends on light intensity, photosensitizer concentration and molecular oxygen concentration. The present work deals with the investigation of blood oxygen saturation in vitro and in vivo during light irradiation in the PDT process. It has been observed that SO2 behavior strongly correlates with the light power density applied for PDT and photosensitizer concentration.