Monitoring of indotricarbocyanine dye fluorescence during photochemotherapy

摘要

As demonstrated by the performed studies, the molecules of tricarbocyanine dye in vivo are localized in the low-permittivity region of the medium, predominantly in the form of contact ion pairs. Comparison of the experimental data and numerical simulation results has revealed that deformation of the dye fluorescence spectrum upon photochemotherapy is due to an increased percentage of methemoglobin (up to 50%) in the total hemoglobin concentration of a tumor tissue. A change in the photosensitizer fluorescence spectrum is observed in the area of a tumor, where laser radiation affects necrosis of the tissues. An analysis of the spectral data enables one to predict a depth and extent of the developed tumor necrosis. With the use of spectral methods, the treatment effectiveness may be optimized by the proper selection of an optimum dose and power density for photoexposure in the process of chemotherapy, with due regard for the character of pathology and individual features of a patient.