Study Of Laser Hyperthermia, Photodynamic Therapy And The Combined Therapy For Human Pancreatic Cancer Cell Line

Abstract

I have conducted laser hyperthermia, photodynamic therapy (PDT) and the combined therapy of laser hyperthermia and PDT for solid tumor of human pancreatic carcinoma transplanted to nude mice. Following experimental therapies have begun 5-6 weeks after transplantation. 1) Laser hyperthermia: The Frosted Probe was punctured under controlling temperature near the margin of a tumor at 42-43C with 3W for 10 minutes. This therapy caused 70-80% necrosis of the total area of pancreatic tumors after 7 days of the treatment. 2) PDT: Argon dye laser was irradiated into a tumor with 300-400mW in 72 hours after hematoporphyrine derivative (HpD) in a dose of 3mg/kg was intravenously injected. Histological changes detected 7 days after the therapy were coagulated necrosis and fibrosis in the tissues ranging from 30-50% of the area. 3) The combined therapy of laser hyperthermia and PDT: A new quartz fiber, which was originally designed to deliver both Nd:YAG laser and argon dye laser simultaneously, was used. Conditions of laser hyperthermia and PDT were same as above. Necrosis amounted 100% of the total area in tumors of 3 out of 6 mice histopathologically 7 days after the therapy. As for the remaining 3 mice, almost all tissues changed into necrosis. Effects of thermal and laser energy to the tumor tissues were also studied by in vitro experiments under the same conditions. The most remarkable decrease in viability was recognized in the combined therapy of laser hyperthermia and PDT among three types of therapies in vitro. The combined therapy of laser hyperthermia and PDT has proven to be highly effective by in vivo and in vitro study using human pancreatic cancer cell line. It will thus be possible to adopt the therapy, with the use of the new quartz fiber, as one of the useful endoscopic laser therapies.