A Study on Photoradiation Therapy of Malignant Glioma Using Argon Laser

在体外模型、大鼠C6脑胶质瘤模型和临床病例中，我们研究了调谐到514.5 nm的Ar激光光疗的效果，并探讨了光疗的细胞损伤机制和对肿瘤细胞的选择性作用。从细胞内摄取HpD和PRT对活细胞的影响，以及透射电子显微镜的观察结果，提示PRT后的初始损伤可能发生在细胞质上。虽然肿瘤细胞对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。本研究还支持肿瘤血管损伤可归因于肿瘤血管对PRT的特异性反应的假说，因为正常内皮细胞对PRT的敏感性低于肿瘤细胞。通过对大鼠C_6胶质瘤模型的研究，得出结论：PRT对肿瘤的初始作用包括肿瘤细胞损伤和肿瘤血管损伤。波长为514.5 nm的Ar激光照射剂量为287J/cm2，HPD剂量为15 mg/kg时，可产生3~5 mm的肿瘤破坏。临床研究提示，PRT可引起肿瘤细胞坏死、血管充血和水肿性改变，而局部温度无明显升高。然而，似乎很难评估PRT的效果并得出关于PRT疗效的结论，因为本研究的患者数量太少。

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.