Combination photodynamic therapy sarcomas M-1 in combination with chemotherapy

Combination of photodynamic therapy and chemotherapy is promising approach for treatment of malignant neoplasms. The use of the modality allows achieving higher efficiency of the treatment, it also allows reducing dose of chemotherapeutics, hence lowering adverse effects of chemotherapy. In the article we present data of our study of efficiency of combined treatment of rats with sarcoma M-1. Photodynamic therapy with photolon and chemotherapy with cisplatin were used as treatment agents. Different treatment schedules and doses of administered photolon and cisplatin were used. Treatment effect was estimated by tumor absolute growth rate, inhibition of tumor growth, and complete tumor regression. We found that photodynamic therapy in 2 hours after photolon administration and administrations of cisplatin in 1 and 4 days after photodynamic therapy with total dose of the chemotherapeutic of 2.5 mg/kg is the most effective treatment schedule. To the end of the study complete regression was observed in 88.9% of rats, inhibition of tumor growth was observed in 99.9% of the animals. Results of the study allow us to conclude that combination of photodynamic therapy with cisplatin is more efficient treatment modality as compared with the delivery of each therapy individually. We found that the use of the most effective treatment schedule resulted in the synergistic effect, therefore reduction of cisplatin dose did not affect treatment efficiency.