Combination therapy for malignant brain tumor model using the stereotactic laser hyperthermia and the new photodynamic therapy

对于立体激光热疗，将一根超强激光纤维(Heraeus激光超音速，CA)插入6F硅胶球囊导管，用生理盐水充气，使激光纤维周围的肿瘤组织缺氧。低氧增强了肿瘤的热效应。将激光功率设置为5W，计算机通过反馈控制特定参数，在45ﾟC的温度下使组织与激光纤维保持10 mm的距离。对移植的大鼠皮下胶质瘤进行45min的热疗。结果：肿瘤的热诱导损伤表现为与激光轴成100ﾟ角的扇形损伤。通过旋转球囊导管中的激光纤维可以治疗整个肿瘤。对于新的光动力学治疗，我们用表皮样癌细胞制作了脑瘤模型。光疗采用日本Hamamatsu Photonics公司生产的Exima Dye激光，经MRI证实为脑瘤后，静脉注射光敏素(4 mg/kg)。激光经皮照射150焦耳。4天后，组织学检查发现肿瘤在距皮质区12 mm范围内凝固性坏死，激光热疗的边界呈波浪状，综合治疗对交界区肿瘤是有效的。结论：对于直径在10 mm以内的颅内小恶性肿瘤，采用综合治疗，侵袭性小，治疗彻底。

To the stereoctic laser hyperthermia, an Ultra Line^<TM> fiber (Heraeus Laser Sonics, CA) was inserted into a 6F silicone balloon catheter, which was inflated with physiologic saline to make the tumor tissue surrounding the laser fiber hypoxic. The hypoxia enhances the thermal effect on the tumor. The laser power was set at 5 watts and a computer, programd with specific parameters using feedback control was used to maintain the tissue 10 mm distant from the laser fiber at a temperature of 45ﾟC.Forty five minutes of hyperthermic treatment was applied to an implanted subcutaneous glioma in rat.Results : The thermal induced damaged in the tumor appeared as a fan-shaped lesion extending at a 100ﾟ angle from the laser beam axis. The entire tumor could be treated by rotating the laser fiber in the balloon catheter.To the new photodynamic therapy, the brain tumor model was made with epidermoid carcinoma cells. The photodyramic therapy was used Exima Dye Laser (Hamamatsu Photonics K.K., Japan).After the brain tumor was confirmed by MRI,the photophyrin^<<encircledR>> (4mg/Kg) was injected into the vein. The Laser was irradiated with 150 Joule percutaneously. After four days, the histological examination revealed the coagulation mecrosis of the tumor within the 12 mm from the cortex.As the boderline by the laser hyperthermic treatment showed the wave-shaped zone, the combination therapy is effective to treat the tumor at the border line area.Conclusion : These showed that the small intracranial malignant tumor (within 10 mm in diameter) can treated by using the combination therapy in less invasively and completly.