915MHz与2450MHz微波在活体与离体猪肝实验中温度曲线与消融范围的比较

Comparison of temperature curve and ablation zone between 915 and 2450 MHz cooled-shaft microwave antennas for porcine livers in vivo and in vitro

目的比较水冷915MHz和2450MHz微波在活体与离体猪肝实验中温度曲线和消融区的差异。方法使用915和2450MHz微波消融和热监测系统，共获得58个消融区和180个温度数据。输出设置为915MHz50W，70W和2450MHz50W，70W，并设置时间为600S。每个温度点的温度曲线在天线旁开5、10、15mm处，对消融区的宽径和长径进行测量。结果在活体与离体实验中，除旁开5mm，915MHz水冷微波其余点的峰值温度[活体50w10mm：（59＋4．26）℃；70W10mm：（67±9．01）℃]均高于2450MHz微波[活体50w10mm：（54±4．09）℃；70w10mm：（57±6．13）℃]（P〈0．05）。在相同条件下，离体肝脏的消融区宽径和长径[活体50w宽径：（3．13±0．76）cm；长径（4．95±0．87）cm]均显着大于2450MHz微波[活体50w宽径：（2．34±0．49）cm；长径（3．43±0．96）cm]（P〈0．05）。结论在离体和活体的肝脏实验中，915MHz水冷微波比2450MHz可以形成更大的消融区和达到更高的温度。

Objective To compare temperature curve and ablation zone between 915 and 2450 MHz cooled-shaft microwave antenna for porcine livers in vivo and in vitro. Methods The 915 and 2450 MHz microwave ablation and thermal monitor system were used in this study. A total of 58 ablation zones and 180 temperature data were obtained from porcine livers in vivo and in vitro. The output settings were 915 MHz 50 W, 70 W and 2450 MHz 50 W , 70 W, and the setting time was 600 s. The temperature curve of every temperature spot was at 5, 10, 15 mm away from the antenna, and the short- and long-axis diameters of the coagulation zones were measured. Results The peak temperatures for the 915 MHz cooled-shaft antenna[in vivo 50 W 10 mm： （59±4.26）℃ ; 70 W 10 mm： （67±9.01）℃ ] were significantly higher than those for the 2450 MHz cooled-shaft antenna [in vivo 50 W 10 mm： （54±4.09）℃;70 W 10 mm： （57±6.13）℃ ] in both in vitro and in vivo livers except for 5 mm away from the antenna in vitro liver（P〈0.05）. Meanwhile, the short- and long-axis diameters for the 915 MHz cooled-shaft antenna[in vivo 50 W short axis： （3.13_＋0.76）em; long-axis （4.95±0.87）cm I were significantly larger than those for the 2450 MHz cooled-shaft antenna [ in vivo 50 W short- axis： （2.34±0.49） cm;long-axis （3.43±0.96） cm in both in vitro and in vivo porcine livers （P〈 0.05）. At the same setting, the short- and long-axis diameters in the in vitro liver increased compared to those in vivo liver, and in 70 W power setting, the peak temperature of every surveying spot in the in vitro liver wassignificantly higher than that in tile in vivo liver （P〈0.05）. Conclusion The 915 MHz cooled-shaft antenna can yiehl a significantly larger ablation zone and achieve higher temperature in ablation zone than a 2450 MHz cooled-shaft antenna in both in vitro and in vivo livers.