Department of Radiology, College of Medicine, Ewha Womans University Mokdong Hospital, Seoul, Republic of Korea.
Korean J Radiol. 2024 Nov;25(11):1003-1010. doi: 10.3348/kjr.2024.0602.
To evaluate the effects of microwave (MW) power and antenna approach methods on extrahepatic tumor seeding and ablation zone size using an ex vivo subcapsular tumor-mimic model.
Forty-one subcapsular tumor mimics were prepared by injecting a mixture of contrast media into bovine liver blocks. Ablation was performed using low- and high-power protocols (75 W and 100 W for 4 and 3 minutes, respectively). The antenna approach was assessed in two directions: parallel and perpendicular to the capsule. CT scans were obtained before and after the ablation to detect contrast leakage on the hepatic surface. The presence of leakage, ablation zone size, and the timing of the first popping sound were compared between the two groups.
Five cases of contrast leakage were observed in the low-power group (n = 21) and 17 in the high-power group (n = 20) (23.8% vs. 85.0%, < 0.001). Contrast leaks were less frequently observed in the low-power protocol compared to the high-power protocol, regardless of the antenna approach (18.2% [2/11] vs. 80.0% [8/10], = 0.009 for parallel access; 30.0% [3/10] vs. 90.0% [9/10], = 0.020 for perpendicular access). The timing of the first popping sound was significantly delayed in the low-power group compared to the high-power group (137.7 ± 51.4 s vs. 77.8 ± 31.4 s, < 0.001). The size of the ablation zone did not differ significantly between the two power groups ( = 0.415). The parallel and perpendicular antenna approaches did not show significant differences in the number of contrast leaks, popping sound timing, or ablation-zone size ( = 0.536, 0.463, and 0.271, respectively).
Low-power MW ablation may be superior to a high-power protocol in reducing the risk of tumor seeding in subcapsular tumors, regardless of the antenna approach.
通过模拟肝包膜下肿瘤的模型，评估微波（MW）功率和天线接近方法对肝外肿瘤种植和消融区大小的影响。
通过将造影剂混合物注入牛肝块中制备了 41 个包膜下肿瘤模拟物。使用低功率和高功率方案（4 分钟分别为 75 W 和 100 W，3 分钟）进行消融。评估了两种天线接近方向：平行和垂直于包膜。在消融前后进行 CT 扫描以检测肝表面的造影剂渗漏。比较两组之间的渗漏存在、消融区大小和首次爆破声的时间。
低功率组（n=21）观察到 5 例造影剂渗漏，高功率组（n=20）观察到 17 例（23.8%比 85.0%，<0.001）。与高功率方案相比，无论天线接近方式如何，低功率方案的造影剂渗漏均较少（平行接近时为 18.2%[2/11]比 80.0%[8/10]，=0.009；垂直接近时为 30.0%[3/10]比 90.0%[9/10]，=0.020）。低功率组首次爆破声的时间明显延迟于高功率组（137.7±51.4 s 比 77.8±31.4 s，<0.001）。两组之间的消融区大小无显著差异（=0.415）。平行和垂直天线接近方式在造影剂渗漏数量、爆破声时间或消融区大小方面均无显著差异（=0.536、0.463 和 0.271）。
无论天线接近方式如何，低功率 MW 消融在降低包膜下肿瘤种植风险方面可能优于高功率方案。
