A Study on Photoradiation Therapy of Malignant Glioma Using Argon Laser

本研究采用波长为514.5nm的氩激光对体外模型、大鼠C_6胶质瘤模型和临床病例进行了光辐射治疗（PRT）的研究，探讨了PRT对肿瘤细胞的损伤机制和PRT对肿瘤细胞的选择性作用。从细胞内摄取HpD和PRT对活细胞作用的观察及透射电镜观察结果表明，PRT后的早期损伤可能发生在细胞质。尽管肿瘤细胞对PRT的敏感性高于其他功能细胞，但肿瘤细胞损伤对PRT的选择性不高。本研究也支持肿瘤血管损伤是肿瘤血管对PRT特异性反应的假说，因为正常内皮细胞对PRT的敏感性低于肿瘤细胞，从大鼠C_6胶质瘤模型的研究中得出结论，PRT对肿瘤的初始效应包括肿瘤细胞损伤和肿瘤血管损伤。用波长为514.5nm的氩激光，剂量为287 J/cm ^2，HpD 15 mg/kg，肿瘤破坏深度为3 ~ 5 mm，临床研究表明，PRT可引起肿瘤细胞坏死、血管扩张和局部水肿，而局部温度无明显升高。然而，由于本研究中的患者数量太少，因此似乎难以评估PRT的效果并得出关于PRT疗效的结论。

We studied on the effect of photoradiation therapy (PRT) using the argon laser tuned to 514.5 nm in the in vitro model, the rat C_6 glioma model and clinical cases.In the in vitro study, mechanisms of cell damage by PRT and the selective effect of PRT on tumor cells were investigated. It is suggested that the initial damage after PRT may occur to the cytoplasm, from observations of intracellular uptake of HpD and the effect of PRT on living cells, and from the findings obtained by transmission electronmicroscope. Although tumor cells were more sensitive to PRT than other functional cells, Cell damage of tumor appeared not to be highly selective to PRT. This study also supports the hypothesis that vascular damage of tumors is attributable to a specific reaction of tumor vessels to PRT, since normal endothelial cells are less sensitive to PRT than tumor cells.From the study of the rat C_6 glioma model, it was concluded that the initial effects of PRT on tumors include both tumor cell damage and tumor vessel damage. Argon laser tuned to 514.5 nm at doses of 287 joules/cm^2 and 15 mg of HpD per kg produced tumor destruction ranging from 3 to 5mm in depth.The clinical study suggested that PRT may produce necrosis of tumor cells, vascular congestions, and edematous change in the irradiated areas without significant elevation of local temperature. It seems, however, difficult to evaluate the effect of PRT and to draw conclusions concerning the efficacy of PRT, because the number of patients in this study is too small.