N₂ dye laser photoradiation therapy with HpD (2nd Report)

-Fundamental and clinical study-

Abstract

The efficiency of photoradiation therapy with N₂ dye laser on gastrointestinal cancer was evaluated and compared to Ar dye laser. After adoministrating HpD to 5 dogs, N₂ dye laser and Ar dye laser were irradiated for 15 and 30 minutes at their liver surface. Liver damage caused by N₂ dye laser at 45mW was almost equal to that caused by Ar dye laser at 180mW. According to the duration times, liver damage became deeper and larger with both lasers at these settings. However, when Ar dye laser was irradiated at 50mW for over15 minutes, the damage did not increase. Treatment of early cancers (6 gastric and one esophageal) with N₂ dye laser photradiation therapy was attempted. All except one disappeared completely and the N₂ dye laser succesfully treated three of these which were not succesfully treated with a Nd-YAG laser. Irradiation with N₂ dye laser at 45mW had the same effect as that of Ar dye laser at 180mW experimentally and clinically.