Abstract
In 1983 we developed a contact method of Nd: YAG laser irradiation using microprobes made of artificial sapphire. Clinical study of this method has yielded excellent results except in depressed typed early gastric cancer.
We pursued a new method of Nd: YAG laser irradiation for the depressed typed early gastric cancer by applying through an interstitial probe for local hyperthertnia using prolonged, low-powerd contact laser irradiation. Since 1984 we have investigated this method in experimental and clinical studies. We obtained the following results: 1) Initial alteration of cancer tissue after laserthermia treatment observed with light microscopy was dominated by the damage of tumor vessels. 2) Mitochondria may by the primary target in the cell destruction process induced by laserthermia in the electron microscopy. 3) Pathlogical change of the gastric wall after lasertherrnia treatments for 18 preoperative patients indicated the satisfactory penetration and safety of lasertherrnia. 4) Expect for 2 patients with depressed undifferenciated cancer, no local recurrence was found on 13 inoperable patients aiming for complete eradication of cancer cells by lasertherrnia. We propose that laserthermia is the safest and most effective form of treatment for deperssed cancer.
