消化器癌に対するレーザー温熱療法の基礎的検討

Abstract

A compaprtive study of laser hyperthermia and microwave hyperthermia was carried out in vivo and in vitro in an attempt to clarify the therapeutic effect and the mechanism. Both therapies, after seven days, caused marked amounts of coagulated necrosesin the transplanted tumors of human pancreatic carcinoma. Immediately after those therapies, electron microscopic examination of the tumor tissues showed membranous, cytoplasmic, nuclear and mitochondrial damage; however, this damage was much more extensive in laser hyperthermia compared to microwave hyperthermia. The cytocidal effects of heating alone, laser hyperthermia and microwave hyperthermia were also studied in vitro. Of the three, laser hyperthermia demonstrated the most notable decrease in viability. Thus, in the mechanism of laser hyperthermia, it seems that the immediate effect is cellular damage caused by both heat energy and Nd: YAG laser light followed by subsequent damage of tumor vessels. On the other hand, laser hyperthermia was conducted for pancreatic carcinoma of Syrian golden hamsters induced by N-nitrosobis- (2-oxypropyl) -amine (BOP). Disappearance of tumor tissues and coagulated necroses were histologically found after seven days. Though the findings of secondary pancreatitis followed by pancreatic carcinoma were recognized in surrounding pancreatic tissues, the effect of laser hyperthermia itself was minimal.