Аннотация
In the paper we explored the possibility of monitoring oxygenation of the tumor tissue through the registration of light diffuse reflectance. This method can also be helpful for assessment the effectiveness of PDT, defining the level of vascular damage and the degree of the tumor oxygenation. We also propose the modification of PDT procedure by using a modulated laser that enables to better maintain the necessary parameters for the PS activation and oxygen generation in irradiated tissues simultaneously allowing to reduce the light dose required for tumor treatment.