FIELD: medicine.SUBSTANCE: invention refers to medicine, namely to diagnostics and photodynamic therapy, and can be used for treating tumorous and inflammatory diseases with application of photodynamic therapy (PDT). PDT is used with the preparation based on a chlorophyll-containing photosensitizer, wherein the photosensitizer is activated outside the body by exposing the preparation to a wave energy source and introducing the treated preparation into the patient's body. If the photosensitizer is activated outside the body, the preparation is additionally enriched with oxygen by bubbling and/or adding an oxygen-containing compound. Wave energy source is exposed to a power density of not less than 10 mWt / cm2 and radiation dose of not less than 0.02 J per 1 ml of preparation. Before administering the preparation, individual patient's parameters of the photodynamic therapy are determined, including the concentration of the photosensitizer in the preparation and its activation parameters. Determination of individual parameters of the PDT involves: taking microbore-containing substrate samples of a patient, treating substrate samples with preparations characterized by different photosensitizer content and activation parameters thereof, - exposure of non-fluorescent detergent samples and determination of nephelometric indices of samples before and after exposure to non-fluorescent detergent, wherein for PDT using a preparation corresponding to a sample with the highest ratio of nephelometric index after exposure to nephelometric index before exposure, or - analysis of growth inhibition area of corresponding microbes when exposed to samples of the preparation, characterized by different content of photosensitizer and parameters of its activation, wherein for PDT using a preparation corresponding to the sample with the highest growth inhibition zone of said microbes. PDT involves periodical control of accumulation of a photosensitizer in patient's tissues by evaluating fl
