[The effect of Nd:YAG laser irradiation on gastric cancer in rats induced by N-methyl-N'-nitro-N-nitrosoguanidine as a model of endoscopic laser treatment for early gastric cancers].

The aim of this report is to prove that cancer tissue is to be eradicated by Nd:YAG laser irradiation and to show the process of its eradication using MNNG induced gastric cancers in rats as a material. Material and Method; in male rats of Wister strain, gastric cancers were induced by 30 weeks administration of 80 mg/1 MNNG solution. Then tumor bearing rats underwent laparotomy and gastrotomy, and tumors were irradiated by the Nd:YAG laser with 30W at the distance of 1cm, total energy ranging 120-1800 joules. These 20 stomachs were examined histologically; 10 of them within 14 days, the rest more than 4 weeks after the irradiation.