915MHz与2450MHz微波在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 MHz and 2450 MHz cooled-shaft microwave antenna：results in ex vivo porcine livers

目的比较915MHz与2450MHz微波在离体猪肝消融实验中温度曲线与消融范围的异同点。方法分别应用915MHz与2450MHz微波进行离体猪肝实验，实验分为4组：50W，60W，70W与80W，作用时间均为600S，共消融56个标本；消融过程于电极旁开5mm、10mm、15mm、20mm与25mm处测温，共得到280点温度曲线。结果915MHz与2450MHz微波的温升曲线均以天线为中心在三维空间上呈逐渐衰减的规律。并且随着微波输出能量的增加，温度曲线的最高温度有逐渐增加的趋势，同时随着距离天线越来越远，温度曲线的最高温度有逐渐下降的趋势。除了旁开5mm位点，915MHz微波的最高温度均高于2450MHz微波（P〈0．05）。915MHz微波消融区的横径与长径均〉2450MHz微波（P〈0．05）。结论915MHz微波在离体猪肝标本中可形成更高且稳定的温度曲线及更大的消融范围。

Objective To compare temperature curve and ablation zone between 915 MHz and 2450 MHz cooled-shaft microwave antenna in ex vivo porcine livers. Methods The 915 MHz and 2450 MHz microwave ablation and thermal monitor system were used in this study. A total of 56 ablation zones and 280 temperature data were obtained in ex vivo porcine livers. The output powers were 50,60,70, and 80W and the setting time was 600s. The temperature curve of every temperature spot, the short- and long-axis diameters of the coagulation zones were recorded and measured. Results At all four power output settings, the peak temperatures of every temperature spot had a tendency to increase accordingly as the output power was increased,and except for 5 mm away from the antenna,the peak temperatures for the 915 MHz cooledshaft antenna were significantly higher than those for the 2450 MHz cooled-shaft antenna （ P 〈0.05）. Meanwhile,the short- and long-axis diameters for the 915 MHz cooled-shaft antenna were significantly larger than those for the 2450 MHz cooled-shaft antenna （ P 〈0.05）. Conclusions The 915 MHz cooledshaft antenna can yield a significantly larger ablation zone and achieve higher temperature in ablation zone than 2450 MHz cooled-shaft antenna in ex vivo porcine livers.