DEVELOPMENT OF COMPUTER TEMPERATURESIMULATION FOR RFINETRSTITIAL HYPERTHERMIA

近十年来，多个研究所采用不同的方法对恶性脑肿瘤患者进行热疗。微波、射频天线和植入体加热的组织间热疗不同于电容热疗，是一种方便的加热方法。所有方法目前仍处于I期或II期研究阶段。射频间质热疗采用我所研制的针式施源器（RE天线），通过立体定向手术，用热敏电阻探头从天线通过放射状导管测量温度。通过导管内温度传感器获得二维温度分布，掌握二维或三维温度分布对于安全有效的热疗非常重要。本研究采用二维有限元法分析了热疗过程中的热分布，并探讨了计算机模拟作为治疗计划的有效性。首先，我们在Workstation（c）平台上建立了二维有限元法的计算机模拟系统，第二年，我们测量了热疗过程中的温度数据和热特性，特别是热清除率的F值。最后，我们研制了一种新型的热模拟系统，并进行了临床试验，其热性能可靠，并已从临床病例中得到验证。我们在3例恶性胶质瘤的热疗治疗中，体验了真正可靠的计算机模拟。但有2例患者行SPECT（单光子发射CT）检查，获得脑血流量信息，我们未能报道，也未能提供完善的模拟系统版本。我们希望下次能达到我们的最终目的。

Hyperthermia for the patients with malignant brain tumor has been developed at multiple institute with different methods in this decade. Interstitial hyperthermia with microwave, RE antenna and implant heating is different from the capacitive hyperthermia and is a convenient method of heating. All methods are now still phase I or II studies.RF interstitial hyperthermia with needle type applicator (RE antenna) which has been developed in our institute was performed by stereotactic surgery measuring the temperature with thermistor probe through the radial catheter from the antenna. Thermal profile were obtained two dimensionally by intracatheter themosensor.It's important for safe and effective hyperthermia to graspthe temperature distribution two or three dimensionally. In this study, we have analyzed the thermal distribution during hyperthermia with two dimensional finite elements method and discussed the efficacy of the computer simulation as a treatment planning.First, we established the computer simulation system with two dimensional finite elements method using Workstation(c).The second year, we measured the temperature data and the thermal properties, especially F value of the thermal clearance rate. Then we have also developed newly RE generaot which was equippedwith automatic tuning and temperature limitation system and have examined it clinically as a phase I - II study.Finally, newly developed computer simulation system with the reliable thermal properties which were obtained from the clinical cases was moving actually. We experienced the really reliable computer simulation in 3 cases with malignant glioma treated with hyperthermia. However, there were 2 cases examined with SPECT (single photon emission CT) to get the information of cerebral blood flow volume, we were not able to report them and the perfect version of simulation system in this time. We hope to achieve our final purpose in next time.