<title>Laser, gamma irradiation, and chemotherapy in treatment of experimental tumors sensitized by porphyrins</title>

Abstract

The new hematoporphyrin derivatives--HpD-1 and dimethoxyhematoporphyrin--DMHp were studied. Their physico-chemical properties, activity in tumor PDT and influence on therapeutic effect of tumor radiation therapy and on toxicity of chemotherapeutic agents were investigated. Hematoporphyrin--Hp was used as control. Data, obtained by absorption spectroscopy, indicated that HpD-1 and DMHp strongly aggregates in aqueous solution and HpD-1 has many covalently bound structures. HpD-1 and DMHp effects in tumor PDT and radiation therapy were studied using 8 species of transplantable tumors. The sensitizers were injected to the animals intraperitoneally in a dosage of 5 - 20 mg/kg. In 48-76 hours after sensitizers were injected, the tumors were irradiated by the pulsed Raman laser pumped by the SHG of YAG:Nd<SUP>3+</SUP> laser. The parameters of this laser system are as follows: the wavelength 630 nm, the pulse duration (tau) equals 1 ns, energy E equals 10 mJ, the repetition rate f equals 10 Hz, average power P equals 100 mW. The goal of our investigation was to attempt to optimize tumor radiation therapy and chemotherapy.