超声造影对射频消融阻断肝癌血供的评价及应用价值

目的探讨超声造影（CEUS）评价经皮射频消融（RFA）阻断肝癌血供的效果以及指导RFA治疗的应用价值。方法选择2006年1月至2007年6月北京大学肿瘤医院就诊的71例肝癌患者共75个病灶，均为富血供肝癌，均因不宜行动脉栓塞化疗术（TACE）或TACE疗效不佳拟行RFA。所有患者均经超声引导下穿刺活检病理证实。71例患者随机分为经皮消融阻断荷瘤血管（PAA）＋褂1A组与单纯RFA组2组。PAA＋RFA组38例患者共39个病灶，首先行CEuS确认肿瘤荷瘤血管及浸润范围，并在彩色多普勒超声引导下进行PAA；即刻行CEUS评估肿瘤区域灌注及荷瘤血管阻断程度，并指导沿肿瘤外周区域及血供区域行肿瘤整体消融。单纯RFA组33例患者共36个病灶，于常规超声引导下进行消融，按计算方案及定位模式治疗，先消融肿瘤深部或临近其他脏器区域。治疗后1、3、6个月对2组患者行增强CT评价疗效。应用t检验比较2组患者消融病灶个数差异，应用矿检验比较2组患者治疗后1、6个月肿瘤病灶灭活率差异。结果PAA＋RFA组患者PAA后即刻CEUS显示31个病灶（79．5％，31／39）瘤内灌注缺失范围超过70％，其中13个病灶（33．3％，13／39）显示肿瘤整体灌注缺失呈边界清晰规整的“日全食”征；8个病灶（20．5％，8／39）灌注缺失范围达40％～70％。PAA＋RFA组38例患者共39个病灶PAA前彩色多普勒超声检查示42支主荷瘤血管良好显示；PAA后即刻彩色多普勒血流成像显示35支（83．3％，35／42）荷瘤血管被阻断，3支（7．1％，3／42）血管血流信号明显减少。PAA＋RFA组每个肿瘤平均消融（3．18±1．42）个球灶，较单纯RFA组每个肿瘤平均消融（4．32±1．56）个球灶少，且差异有统计学意义（t=-2．524，P=0．015）。治疗后1个月PAA＋RFA组肿瘤病灶灭活率为92．3％（36／39），高于单纯RFA组的66．7％（24／35），且差异有统计学意义（x^2=8．264，P=0．001）。结论CEUS证实PAA可成功阻断或减少荷瘤血供，增大射频凝固坏死区，有效降低富血供大肿瘤RFA复发率；重视CEUS指导PAA下RFA治疗，可减少消融病灶数目，有较高的应用价值。

The role of contrast enhanced ultrasound in evaluating and guiding radiofrequency ablation of hepatocellular carcinoma and feeding vessels

Objective To investigate the role of contrast enhanced ultrasound （CEUS） in evaluating and guiding radioffequency ablation （RFA） of hepatocellular carcinoma （HCC） and its feeding vessels. Methods From January 2006 to June 2007, 71 patients with 75 hypervascular HCC in Peking University Cancer Hospital who underwent RFA were included in the study. The diagnosis was confirmed by ultrasound guided biopsy for all patients. These patients were not suitable for transcatheter arterial chemoembolization （TACE） or had poor responds to TACE. They were divided into two groups, which included group percutaneous artery ablation （PAA） combining RFA and group RFA. There were 38 patients with 39 HCC in group PAA combining RFA and CEUS were used to identify the range of HCC infiltration. Firstly, PAA of the feeding vessels was conducted under the guidance of color doplor flow imaging （CDF1）. Then CEUS was performed to evaluate HCC perfusion after blocking the feeding vessels. Finally, the rest of the tumor was ablated by RFA. In group RFA, there were 33 patients with 36 HCC, who did not undertake PAA before RFA. Generally, the RFA was planned based on tumor size and location, and the ablation started with deep part of HCC or portion close to nearby organs. Contrast CT was used as a post-RFA imaging for follow-up at 1, 3 and 6 months post-RFA. T test was used to compare the difference in focal lesions number between two groups, and ,~ tests were used to compare the difference in necrosis rate between two groups after treatment. Results In group PAA combining RFA, post-PAA CEUS showed intratumor perfusion decreased more than 70% in 31 HCC （79.5%, 31/39）. Of them, 13 HCC （33.3%, 13/39） showed complete perfusion defect with clear margin, called ＂solar eclipse sign＂. The rest 8 HCC （20.5%, 8/39） showed 40%- 70% of perfusion defect. In group PAA combining RFA, CDFI showed 35 （83.3%, 35/42） feeding vessels were blocked, and 3 vessels （7.1%, 3/42） showed significant decreased flow signal after PAA. There were average 3.18±1.42 ablations per HCC in group PAA combining RFA, and 4.32±1.56 in group RFA. The number of ablations per HCC in group PAA combining RFA was significantly less than group RFA （t=2.524, P=-0.015）. The tumor necrosis rate at 1 month post-RFA in group PAA （92.3%, 36/39） combining RFA was significantly higher than that of group RFA （66.7%, 24/35） 0（2=8.264, P=0.001）. Conclusions With CEUS, PAA can effectively block the feeding vessels of HCC, enhance ablated necrosis in the tumor and significantly increase necrosis rate post-RFA for large hypervascular HCC. CEUS-assisted PAA can improve efficiency of RFA with less ablation number and better result.