THE RESEARCH OF THE DIFFERENTIAL HYPOTHERMIA THERAPY FOR BRAIN TUMORS

为了将差分低温治疗人脑恶性肿瘤的临床应用，我们研究了外部微波辐射对肿瘤的面积和深度的影响，为了在更精确的温度下对更准确的区域进行加热，接下来利用组织间微波辐射天线进行体内实验。在全身低温(30ﾟC)条件下，微波天线对距天线半径2 cm、距脑表面3 cm深度的区域进行37ﾟC以上的加热，显示了治疗效果，但由于天线表面过热(50ﾟC以上)，天线附近组织出现凝血、坏死和出血。为了防止过热，研制了一种用于间质微波治疗的天线冷却系统，该系统由一根外径为5.0 mm的硅胶管构成。由CON…提供的冷却更稳定的水灌流可以使组织温度在半径1厘米范围内42至44ﾟC的范围内更均匀和准确地加热。通过组织学检查，该系统的安全性得到了保证。此外，在耦合的冷却系统中，将四根天线组成的方形阵列(每侧1.6 cm)插入脑内。在这个四天线实验中，热场显著变平，体积减小，但冷却系统显著扩大了维持在治疗温度范围(42-45ﾟC)的面积。在差分低温下，测量了正常猴脑加热前后的局部脑血流量。加热前白质的1-CBF为18.7+-9.8ml/100g脑/分钟，加热后(30ﾟ℃)较加热前增加约2个小时。这种选择性增加的CBF有利于未来的化疗，我们致力于开发更有效的天线和天线引导系统，从病理学的角度观察加热正常脑组织的变化，并检查加热脑组织的极限点。较少

For the purpose of the clinical application of the differential hypothermia for human malignant brain tumors, we have studied the area and the depth that were affected by the external microwave irradiation.In order to heat more exact area at more exact temperature, next in vivo experiments were performed by using the interstitial microwave irradiation antenna. Under the generalized hypothermia (30ﾟC), a microwave antenna heated the area within 2 cm radius from the antenna and 3cm in depth from the brain surface at the degree of over 37ﾟC.This result indicated the therapeutic effect.But it is one of the problems with this system that because of the overheating (more than 50ﾟC) of the antenna surface, coagulation, necrosis and bleeding were observed in the tissues adjacent to the antenna. In order to prevent the overheating, a antenna cooling system for interstitial microwave therapy was developed, which was constructed of a silicone tube 5.0 mm in outer diameter. Cooling provided by con … More stant water perfusion allowed more uniform and accurate heating in the tissue temperatures the range of 42 to 44ﾟC within 1 cm radius. And the safety of this system was ensured by the histological examination.Moreover a square array (1.6cm on a side) of four antennae was inserted into the brain with the coupled cooling system. In this four-antennae experiments, thermal field was dramatically flattened with minimal reduction in size ; however, the area maintained at a therapeutic temperature range (42-45ﾟC) was significantly enlarged by the cooling system.Under differential hypothermia, the lical cerebral blood flow (1-CBF) before and after the heating of the normal monkey brain was measured. Before heating, the 1-CBF of the white matter was 18.7<plus-minus>9.8ml/100g brain/min, after heating (30ﾟC), that was increased about two hold compared with before heating. This selective increase of CBF was favorable for the chemotherapIn future, we attend to develop more effective antenna and the antenna guiding system, to investigate the change of the heated normal brain tissue from the pathological point of view and to examine the limiting point of heating the brain tissue. Less