Abstract
Hyperthermia has therapeutic benefit to the cancer patient, however the technology for producing safe and effective gastrointestinal hyperthermia is very difficult. In an attempt to obtain basic data for endoscopical local hyperthermia using non-contact Laser irradiation, the temperature profiles and the antitumor effect have been studied using cultured cells of human hepatocellular carcinoma (PLC/PRF/5) and nude mice bearing transplanted tumor of the same carcinoma cells. The surface and internal temperature of the tumor exposed to Argon Laser (514.5 nm), Argon dye Laser (630 nm), and Nd-YAG Laser (1060 nm) measured with the infrared thermography and the gold plated thermister. As a result, Nd-YAG Laser was the most effective Laser for the local hyperthermia in point of the elevation rate of intratumor temperature. The antitumor effect was assessed by both single and double treatment of 30 minutes local hyperthermia using Nd-YAG Laser and/or 2.0 mg/kg of MMC I. P.. The central surface temperature of the tumor was controlled to 46°C by the infrared thermography. Relative mean tumor volumes were minimal after 1 week of treatment. T/C ratios were control group 100%, MMC group 58.2%, hyperthermia group 32.1%, and hyperthermia+ MMC group 13.9% respectively. Histological changes were also studied. Histological findings, which were examined immediately after local hyperthermia, showed that degenerative changes of tumor cells were mild but marginal microvascular injuries of the tumor were remarkable. The fundamental studies suggest that the local hyperthermia using non-contact Nd-YAG Laser irradiation with or without chemotherapy may be one of the most beneficial therapeutic method for human gastrointestinal cancer.
