Paiban骨组织单电极射频消融的范围及热场分布

Lesion volume and thermal field distribution of single-electrode radiofrequency ablation in Paiban bone tissue

背景:保证射频消融治疗效果的关键问题是准确判定病灶内的加热温度及范围。目的:观察骨组织单电极射频消融的范围和热场分布情况。设计、时间、地点:对比观察实验,于2007-09/12在上海长海医院中心实验室完成。材料:成年黄牛胫骨新鲜标本15例,MSIS-1500型射频仪为美国迈德医疗科技有限公司生产。方法:使用射频仪及单电极射频针对15例新鲜牛胫骨标本进行射频消融,设置中心温度95℃,持续15min,消融中测量电极旁20mm范围内骨皮质和骨髓内16个测温点的温度。主要观察指标:消融过程中各测温点温度随时间变化及骨组织内部凝固形态和范围。结果:在骨髓和骨皮质分别形成以电极为中心半径为10mm和5mm的50℃以上高温区;电极周围骨皮质成苍白色,界限不清;骨髓凝固区域沿电极呈纵椭圆形,垂直电极方向最大横经约17.2mm,沿电极方向的最大长径平均约23.6mm。结论:单电极骨组织射频消融范围较小,用于较大骨肿瘤的治疗需多点次消融;骨皮质有明显隔热作用。

BACKGROUND： Lesion volume and thermal field distribution can influence effect of percutaneous radiofrequency ablation. OBJECTIVE： To investigate the lesion volume and thermal field distribution of single-electrode radiofrequency ablation in bone tissue. DESIGN, TIME AND SETTING： Comparative observation experiment was performed at the Central Laboratory of Changhai Hospital from September to December 2007. MATERIALS： Fifteen specimens of fresh bovine tibia; MSI S-1500 radiofrequency generator （Medsphere International, Inc. USA）. METHODS： Radiofrequeney ablation was performed in fresh bovine tibia using radiofrequency generator accompanied by a 15G single radiofrequency electrode probe, with a central temperature of 95 ℃ for 15 minutes. Temperatures of 16 sites about 20 mm around the inserted probes in the marrow canal and cortex were monitored by thermocouples. MAIN OUTCOME MEASURES： The lesion volume and the change of temperature with time around single radiofrequency electrodes in bone tissue. RESULTS： Hyperthermia （〉 50 ℃） was generated perpendicularly to the probe about 10 mm and 5 mm approximately in bone marrow and cortical bone, respectively. The cortical bone around electrodes exhibited pale color with unclear interface. The coagulatory regions due to ablation appeared to be an oval-shape distribution along the probe, with an average area about 23.6 mm× 17.2 mm. CONCLUSION： The scope of single-electrode radiofrequency ablation is small, so it is better to perform multi-target ablation for large bone tumor. Cortical bone exhibits obvious heat insulation effect.