RESUMEN
The efficiency of photodynamic therapy with photosensitizer Tiosens (Russia) was evaluated in mono- and combined therapy of rats with malignant gliomas (glioblastoma 101/8, oligodendroglioma 14-4-9, and C6 glioma). The efficiency of photodynamic monotherapy was not high: the animals died from brain edema developing in tumor tissue and in the adjacent normal cerebral tissue. Pathomorphological studies of tumor tissue detected necrosis and apoptosis, destruction of vessels with hemorrhages, and vascular thrombosis. Combined therapy for malignant gliomas including Tiosens photodynamic therapy and subsequent temodal or lysomustine chemotherapy, was the most effective. In glioblastoma 101/8, combined therapy with lysomustine or temodal led to prolongation of the lifespan by 127 %; 62.5 and 50 % rats were cured, respectively; in oligodendroglioma 14-4-9, animal lifespan was prolonged by 80 and 60 %, with 43 and 45 % rats cured, respectively. Glioma C6 was least sensitive to therapy.