RESEARCH FOR COMBINED THERAPY WITH INTERSTITIAL MACROWAVE HYPERTHERMIA AND INTERSTITIAL IRRADIATION FOR MALIGNANT BRAIN TUMORS

1)间质照射为研究间质照射对正常脑组织的影响，将Ir-192种子立体定向植入成年日本猴的大脑半球。通过神经学检查、神经影像学检查和组织学检查评估对脑的影响。辐照剂量超过200-260 Gy的区域出现明显的损伤，如坏死。急性期以放射性水肿最为明显，此后逐渐减轻，持续6个月。剂量率、总剂量、剂量、辐照体积的相对贡献有待进一步研究。2)间质性高温从微波间质性高温引起的即时和延迟组织学改变来判断正常脑组织的热损伤。在冷却系统内的微波天线被插入大脑半球。在参考点温度保持在42,4…更多的3,44,45和46ºC 60分钟。在44ºC以下加热的区域没有明显的不可逆变化，在44ºC或以上加热的区域出现凝固性坏死。这些组织学结果表明，在44ºC或更高的温度下加热60分钟后会发生热损伤，并建议43ºC加热60分钟为热损伤的安全极限。3)临床试验采用BRW立体定向系统对11例复发或不可切除的恶性脑肿瘤进行192Ir粒子间质照射治疗。2例患者同时接受间质热疗联合间质放疗。1例患者肿瘤消失，11例患者中5例出现肿瘤消退。结果提示间质照射和高热治疗对恶性脑肿瘤是有效的。然而，在这项研究中，人数少，随访时间短，无法得出任何关于疗效的结论。需要进一步的临床和基础研究来确定间质照射和热疗在治疗恶性脑肿瘤中的价值。少

1) Interstitial IrradiationTo investigate the effects of interstitial irradiation on normal brain tissue, Ir-192 seeds were stereotactically implanted into the cerebral hemisphere of adult Japanese monkeys. The effects on the brain were evaluated with neurological examination, neuroradiography and histological examination. Significant damage such as necrosis was observed on the area irradiated more than 200-260 Gy. The radiation-induced edema was most prominently observed in the acute stage and thereafter decreased gradually up to 6 months. The further researchs were necessary to determine the relative contributions of dose rate, total, dose, irradiated volume.2) Interstitial HyperthermiaThe theramal damage of normal brain tissure was estimated from the immediate and delayd histological changes caused by microwave intersititial hyperthermia. A microwave antenna within a cooling system was inserted into the cerebral hemisphere. The temperature at a reference point was maintained at 42,4 … More 3,44,45 and 46ﾟC for 60 minutes. Areas heated below 44ﾟC showed no obvious irreversible change and areas heated at 44ﾟC or above showed coagulative necrosis. Those histological findings indicate that the thermal damage occurs after at 44ﾟC or above for 60 minutes, and suggest that the safety limit for brain hyperthermia is 43ﾟC for 60 minutes.3) Clinical TrialEleven patients with recurrent or unremovable malignant brain tumors were treated by interstitial irradiation with 192Ir seeds using BRW stereotactic systems. Two patients also recieved the interstitial hyperthermia in combination with interstitial iiradiation. In one patient, the tumor had disappeard, and tumor regression was observed in 5 patients of the 11 patients. The results suggest that interstitial irradiation and hypertermia are useful for malignant brain tumors. However, in this study the small numbers and short follow-up preclude any conclusions regarding efficacy. Additional clinical and basic research should be obtained to determine the value of interstitial irradiation and hyperthermia in th treatment of malignant brain tumors. Less