射频消融在离体椎体肿瘤模型中热场的分布

The heat distribution of radiofrequency ablation in the ex vivo vertebral tumor model

目的 观察离体椎体肿瘤模型中射频消融（RFA）的热场分布及椎体后皮质的隔热作用,探讨射频消融治疗椎体肿瘤的有效杀伤范围及椎体后皮质对脊髓的热保护作用.方法 制作离体肿瘤模型共30具,选用10具,分别于75、80、85、90、95℃进行射频消融,测量不同作用针长（1.0、2.0 cm）、不同设置温度在离体肿瘤模型中有效射频消融范围.选用20具新鲜成年猪腰椎标本,随机分为椎体后皮质完整组和椎体后皮质破坏组,制作两组肿瘤模型,分别于95 ℃进行射频消融,对椎体后皮质前后侧进行实时测温并记录.结果 射频电极针裸露1.0cm时,温度控制在75、80、85、90、95℃时RFA在离体椎体肿瘤模型中有效消融范围半径均未超过5.0mm,分别为（3.80±0.79）、（4.10±0.74）、（4.30 ±0.82）、（4.40±0.84）、（4.50±0.71） mm.射频电极针裸露2.0 cm时,温度控制在75、80、85、90、95℃时RFA在离体椎体肿瘤模型中达到50℃的消融范围半径分别为（6.40 ±0.52）、（7.40±0.71）、（8.00±0.67）、（8.20 ±0.63）、（8.30±0.68） mm.椎体后皮质完整组椎体后皮质前侧、后侧温度分别为（50.28 ±4.21）、（38.26 ±4.47）℃,其前后侧温度差异有统计学意义（P＜0.05）;破坏组椎体后皮质前侧、后侧温度分别为（51.07±4.23）、（49.27 ±3.84）℃,其前后侧温度差异无统计学意义（P＞0.05）.结论 在离体椎体肿瘤模型中,2.0cm作用针长在杀灭肿瘤过程中安全、有效,并且椎体后皮质对脊髓具有热保护作用.

Objective To investigate the heat distribution of radiofrequency ablation （RFA） in the ex vivo vertebral tumor model and heat isolation effect of posterior cortical bone using UniblateTM Rita electrode,and to evaluate the valid range of RFA treating vertebral tumor lesion and the thermal protection of posterior cortical bone to the spinal cord.Methods Ten fresh lumbars excised from adult swines were used to creat the ex vivo vertebral tumor model.Radiofrenquency was performed at 75,80,85,90,and 95 ℃ with 1.0 cm and 2.0 cm electrode tips.The valid range of RFA was measured in the ex vivo vertebral tumor model with diffierent electrode tips and diffierent setting temperatures.Twenty fresh lumbars excised from adult swines were divided into intact posterior cortical bone group and defect posterior cortical bone group randomly,creating the intact posterior cortical bone tumor model and defect posterior cortical bone tumor model respectively.Radiofrenquency was performed at 95 ℃ with 2.0 cm electrode tip.The anterior and posterior temperature of posterior cortical bone in the ex vivo vertebral tumor model was recorded.Results RFA range in the ex vivo vertebral tumor modle didn＆#39; t exceed 5 mm at 75,80,85,90,and 95 ℃ with 1.0 cm electrode tip.The radiuses of RFA range in the ex vivo vertebral tumor model were （6.40 ±0.52）,（7.40±0.71）,（8.00 ±0.67）,（8.20 ±0.63） and （8.30 ±0.68） mm at 75,80,85,90,and 95 ℃ with 2.0 cm electrode tip,respectively.The anterior and posterior temperature of posterior cortical bone in the intact group was （50.28 ±4.21） and （38.26 ±4.47） ℃ （P 〈0.05） ; The anterior and posterior temperature of posterior cortical bone in the defect group was （51.07 ± 4.23） and （49.27 ± 3.84） ℃ （P 〉 0.05）.Conclusion In the ex vivo vertebral tumor model,RFA was safe and effective with 2-cm electrode tip.Posterior cortical bone can protect the spinal cord in the process of RFA.