de Vrind H H, van Dam W M, Wondergem J, Haveman J
Department of Radiotherapy, University of Amsterdam, Academisch Medisch Centrum, The Netherlands.
Int J Radiat Biol. 1993 Jan;63(1):83-9. doi: 10.1080/09553009314550111.
The influence of X-irradiation on the sensitivity of the rat sciatic nerve to local hyperthermia was investigated. A 10 or 20 mm long segment of the nerve was irradiated intraoperatively using 50 kV X-rays. Hyperthermia (30 min at 45 degrees C), was applied to the irradiated part (over a length of 5 mm) of the nerve using a brass thermode. Functional damage to the nerve was assessed using the toe-spreading test, which mainly assesses the motor function of the sciatic nerve. Radiation alone (doses up to 70 Gy) did not lead to detectable damage for at least 90 weeks. Hyperthermia alone (30 min at 45 degrees C) resulted in complete loss of motor function. This function loss was transient and complete recovery took place in about 4 weeks. Recovery time was scored as the number of days between hyperthermia and the day on which 50% of the motor function had returned. Irradiation (35 Gy) of a nerve segment, which included the heated part, resulted in a delayed recovery from the heat treatment compared to controls (heat only). The time interval and sequence between irradiation and hyperthermia hardly influenced the recovery delay. The size of the irradiated nerve segment did influence the recovery delay. Irradiation of a 20 mm nerve segment led to longer recovery delays than irradiation of a 10 mm segment (a delay of 5-10 days and 1-5 days respectively). A dose-response relation for the irradiation-induced delay in recovery was observed when a large segment (20 mm) of the nerve was irradiated immediately after heat with a dose ranging from 5 to 40 Gy. The delay in heat recovery was dose-dependent below 20 Gy, but after radiation doses above 20 Gy the recovery delay remained almost constant.
研究了X射线辐射对大鼠坐骨神经局部热疗敏感性的影响。术中使用50 kV X射线对10或20 mm长的神经节段进行照射。使用黄铜热电极对神经的照射部位（长度为5 mm）施加热疗（45℃，30分钟）。使用趾展试验评估神经的功能损伤，该试验主要评估坐骨神经的运动功能。单独辐射（剂量高达70 Gy）至少90周内未导致可检测到的损伤。单独热疗（45℃，30分钟）导致运动功能完全丧失。这种功能丧失是短暂的，约4周后完全恢复。恢复时间记为热疗与运动功能恢复50%之日之间的天数。与对照组（仅热疗）相比，对包括受热部位在内的神经节段进行辐射（35 Gy）会导致热疗后的恢复延迟。辐射与热疗之间的时间间隔和顺序几乎不影响恢复延迟。照射神经节段的大小确实会影响恢复延迟。照射20 mm神经节段比照射10 mm神经节段导致的恢复延迟更长（分别延迟5 - 10天和1 - 5天）。当在热疗后立即对一大段（20 mm）神经进行5至40 Gy剂量的辐射时，观察到辐射诱导的恢复延迟的剂量反应关系。在20 Gy以下，热恢复延迟与剂量相关，但在辐射剂量高于20 Gy后，恢复延迟几乎保持不变。
