Abstract：
OBJECTIVE: Percutaneous thermal ablation is an effective treatment for primary and metastatic liver tumors and is a recommended local therapy for early-stage hepatocellular carcinoma (HCC). Reported evidence shows an increase in the ablation zone volume over the first 24-h post-liver ablation. This report compares ablation zone volumes immediately at the completion (T = 0) of 26 microwave ablations of liver tumors to 24-h post-procedure (T = 24) volumes.
METHODS: 20 patients, 13 (65%) males, underwent a total of 26 hepatic microwave ablations (MWA) under ultrasound guidance. Contrast-enhanced CT (CECT) or MRI was performed immediately and another CECT 24 h post operatively. Evaluation of the ablation zone and comparison of the two post-operative scans were done using BioTrace software. The expansion of ablation zones on post-op CECTs was matched point by point per direction. The distance between each 2 points was measured and grouped by distance. The incidence of each specific distance was then converted into a percentage, first for each case separately, then for all cases altogether. Data were tested by a matched paired one-sided t test.
RESULTS: The median lesion diameter was 1.5 cm (range 0.5-3.3) with 16 (62%) HCC cases and 9 hepatic metastases (4 neuroendocrine carcinoma, 4 colorectal carcinomas, 1 breast carcinoma, 1 pancreatic cancer). The data show a consistent volume expansion greater than 30% (p = 7.7e-5) 24-h post-ablation, where the median expansion is 57%. Distances between T = 0 and T = 24 equal to 3-7 mm occur in over 35% of the cases.
CONCLUSIONS: The ablation zone expansion at 24-h post-op was not uniform. The final ablation zone is difficult to predict at the time of the procedure. The awareness of the ablation zone expansion is important when treating near-critical structures, managing the heat sink effect, and preserving liver parenchyma.
METHODS: 20 patients, 13 (65%) males, underwent a total of 26 hepatic microwave ablations (MWA) under ultrasound guidance. Contrast-enhanced CT (CECT) or MRI was performed immediately and another CECT 24 h post operatively. Evaluation of the ablation zone and comparison of the two post-operative scans were done using BioTrace software. The expansion of ablation zones on post-op CECTs was matched point by point per direction. The distance between each 2 points was measured and grouped by distance. The incidence of each specific distance was then converted into a percentage, first for each case separately, then for all cases altogether. Data were tested by a matched paired one-sided t test.
RESULTS: The median lesion diameter was 1.5 cm (range 0.5-3.3) with 16 (62%) HCC cases and 9 hepatic metastases (4 neuroendocrine carcinoma, 4 colorectal carcinomas, 1 breast carcinoma, 1 pancreatic cancer). The data show a consistent volume expansion greater than 30% (p = 7.7e-5) 24-h post-ablation, where the median expansion is 57%. Distances between T = 0 and T = 24 equal to 3-7 mm occur in over 35% of the cases.
CONCLUSIONS: The ablation zone expansion at 24-h post-op was not uniform. The final ablation zone is difficult to predict at the time of the procedure. The awareness of the ablation zone expansion is important when treating near-critical structures, managing the heat sink effect, and preserving liver parenchyma.
摘要：
目的：经皮热消融是原发性和转移性肝肿瘤的有效治疗方法，是早期肝细胞癌（HCC）的推荐局部治疗方法。报告的证据表明，在肝脏消融后的第一个24小时内，消融区体积增加。本报告将26例肝肿瘤微波消融完成时（T=0）的消融区体积与术后24小时（T=24）体积进行了比较。
方法：20例患者，13名（65%）男性，在超声引导下总共进行了26次肝微波消融（MWA）。立即进行对比增强CT（CECT）或MRI，并在术后24小时进行另一次CECT。使用BioTrace软件进行消融区的评估和两次术后扫描的比较。术后CECT上消融区的扩展在每个方向上逐点匹配。测量每2个点之间的距离并按距离分组。然后将每个特定距离的发生率转换为百分比，首先分别针对每种情况，然后是所有案件。数据采用配对单侧t检验。
结果：中位病变直径为1.5cm（范围0.5-3.3），其中16例（62％）HCC和9例肝转移（4例神经内分泌癌，4大肠癌，1乳腺癌，1胰腺癌）。数据显示消融后24小时体积膨胀大于30%(p=7.7e-5)。其中中位数扩张为57%。在超过35%的情况下,T=0和T=24之间的距离等于3-7mm。
结论：术后24小时消融区扩张不均匀。最终消融区在手术时很难预测。在治疗近临界结构时，对消融区扩张的认识很重要，管理散热效果，并保留肝实质.
方法：20例患者，13名（65%）男性，在超声引导下总共进行了26次肝微波消融（MWA）。立即进行对比增强CT（CECT）或MRI，并在术后24小时进行另一次CECT。使用BioTrace软件进行消融区的评估和两次术后扫描的比较。术后CECT上消融区的扩展在每个方向上逐点匹配。测量每2个点之间的距离并按距离分组。然后将每个特定距离的发生率转换为百分比，首先分别针对每种情况，然后是所有案件。数据采用配对单侧t检验。
结果：中位病变直径为1.5cm（范围0.5-3.3），其中16例（62％）HCC和9例肝转移（4例神经内分泌癌，4大肠癌，1乳腺癌，1胰腺癌）。数据显示消融后24小时体积膨胀大于30%(p=7.7e-5)。其中中位数扩张为57%。在超过35%的情况下,T=0和T=24之间的距离等于3-7mm。
结论：术后24小时消融区扩张不均匀。最终消融区在手术时很难预测。在治疗近临界结构时，对消融区扩张的认识很重要，管理散热效果，并保留肝实质.
