From the Department of Diagnostic Imaging, The Warren Alpert Medical School of Brown University, 593 Eddy St, Providence, RI 02903.
Radiology. 2019 May;291(2):504-510. doi: 10.1148/radiol.2019181652. Epub 2019 Feb 12.
Background Thermal ablation of cancers may be associated with high rates of local tumor progression. A thermal accelerant gel has been developed to improve the transmission of microwave energy in biologic tissues with the aim of enlarging the thermal ablation zone. Purpose To determine the effects of a thermal accelerant gel on microwave ablation zone volumes in porcine lung and to compare percutaneous and endobronchial delivery methods. Materials and Methods Thirty-two consecutive microwave lung ablations were performed in nine 12-week-old domestic male swine under general anesthesia by using fluoroscopic guidance between September 2017 and April 2018. Experimental ablations were performed following percutaneous injection of thermal accelerant into the lung ( = 16) or after endobronchial injection by using a flexible bronchoscope ( = 8). Control ablations were performed without accelerant gel ( = 8). Lung tissue was explanted after the animals were killed, and ablation zone volumes were calculated as the primary outcome measure by using triphenyltetrazolium chloride vital staining. Differences in treatment volumes were analyzed by generalized mixed modeling. Results Thermal accelerant ablation zone volumes were larger than control ablations (accelerant vs control ablation, 4.3 cm [95% confidence interval: 3.4, 5.5] vs 2.1 cm [95% confidence interval: 1.4, 2.9], respectively; < .001). Among ablations with the thermal accelerant, those performed following percutaneous injection had a larger average ablation zone volume than those performed following endobronchial injection (percutaneous vs endobronchial, 4.8 cm [95% confidence interval: 3.6, 6.4] vs 3.3 cm [95% confidence interval: 2.9, 3.8], respectively; = .03). Ablation zones created after endobronchial gel injection were more uniform in size distribution (standard error, percutaneous vs endobronchial: 0.13 vs 0.07, respectively; = .03). Conclusion Use of thermal accelerant results in larger microwave ablation zone volumes in normal porcine lung tissue. Percutaneous thermal accelerant injection leads to a larger ablation zone volume compared with endobronchial injection, whereas a more homogeneous and precise ablation zone size is observed by using the endobronchial approach. © RSNA, 2019 See also the editorial by Goldberg in this issue.
背景 癌症的热消融可能与局部肿瘤进展率高有关。为了提高微波能量在生物组织中的传输效率，扩大热消融区域，已经开发出一种热加速凝胶。目的 确定热加速凝胶对猪肺微波消融区域体积的影响，并比较经皮和支气管内输送方法。材料与方法 2017 年 9 月至 2018 年 4 月，在全身麻醉下，使用透视引导，在 9 只 12 周龄的雄性家猪中进行了 32 例连续的微波肺消融术。实验性消融是在经皮注射热加速剂进入肺（=16）或使用可弯曲支气管镜经支气管内注射（=8）后进行的。未使用加速凝胶的控制消融（=8）。动物死后取出肺组织，使用三苯基四唑氯化物活体染色计算消融区域体积作为主要观察指标。通过广义混合模型分析处理体积的差异。结果 热加速消融区域体积大于对照组（加速剂与对照组消融，4.3cm[95%置信区间：3.4，5.5]比 2.1cm[95%置信区间：1.4，2.9]；<0.001）。在使用热加速剂的消融中，经皮注射的平均消融区域体积大于经支气管内注射（经皮与经支气管内，4.8cm[95%置信区间：3.6，6.4]比 3.3cm[95%置信区间：2.9，3.8]；=0.03）。支气管内凝胶注射后形成的消融区域在大小分布上更加均匀（标准误差，经皮与经支气管内：0.13 比 0.07；=0.03）。结论 在正常猪肺组织中使用热加速剂可使微波消融区域体积增大。与支气管内注射相比，经皮热加速剂注射可导致更大的消融区域体积，而支气管内方法可观察到更均匀和精确的消融区域大小。版权所有©2019，美国放射学会。 本研究由美国国立卫生研究院（1R01CA176502）资助。 还请参见本期杂志中 Goldberg 的社论。
