目的：通过射频消融前超声造影观察肿瘤大小、数目及分布，探讨其对筛选适应证的应用价值。方法：北京大学临床肿瘤学院超声科就诊的164例确诊肝细胞癌（hepatocellular carcinoma，HCC）并符合经皮射频消融（radiofrequency Ablation，RFA）入选标准患者，随机分为两组进行对照研究。81例射频消融前采用SonoVue行超声造影（contrast-enhanced ultrasound，CEUS）检查（CEUS组），83例射频消融前未行超声造影检查（对照组）。男121例、女43例;年龄38～72岁，平均5214岁。造影前两组病例的临床资料差异无统计学意义。肿瘤平均直径超声造影组316cm，对照组315cm。治疗后采用常规超声，增强CT和/或超声造影等影像检查进行规律性随访。结果：超声造影组81例造影后9例（11.1%）因发现肿瘤数目> 5个（5例）、范围测量>8cm（2例）、侵及2支大血管或肠管（2例）被确定为非射频消融适应证，余72例101灶行射频消融治疗。其中超声造影新发现≤117cm 8例12灶中，5例为肝硬化及肝细胞癌治疗后随访病例，3例7个灶为肝细胞癌卫星灶。另有16灶为常规超声不能定性或误诊良性，经超声造影确认并指导射频消融治疗。两组随访6～36个月，超声造影组与对照组消融成功率分别为95.0%和89.6%（P>0.05）。对照组新生率高于超声造影组（22.9% vs 9.7%，P<0.05）。结论：射频消融前超声造影有助于筛选适应证，显著减少新生转移病例。造影所获信息为早期检出微小癌灶提供了手段和依据，从而有效的提高射频消融对肝癌的治疗水平。

目的：总结射频消融（radiofrequency ablation，RFA）对肝恶性肿瘤的治疗效果，探讨并发症类型及处理措施。方法：对343例778个肝恶性肿瘤行582人次超声引导RFA治疗。其中原发性肝癌（HCC）212例，448个癌灶，肿瘤最大径平均4.0cm，根据国际抗癌协会的肿瘤分期，其中63例（29.7%）为Ⅰ～Ⅱ期，149例（70.3%）为Ⅲ～Ⅳ期（含43例手术切除后复发癌）。肝转移癌（MLC）131例，330个癌灶，癌灶直径平均为3.9cm，原发灶69.5%（91例）来自胃肠道。治疗原则为消融范围超过癌周0.5～1.0cm；对较大肝肿瘤，采用较规范的计算方案指导射频治疗。治疗中密切观察图像异常改变，监测生命体征，以便及时发现出血及周围损伤。治疗后24 h内或1个月后增强CT检查肿瘤无活性为治疗成功。随访时间为2～62个月。结果：射频治疗成功率HCC为95.5%（428/448灶），MLC为96.4%（318/330灶）；局部复发率分别为8 5%（38/448灶），11.8%（39/330灶）。共有138例（40.2%）由于肿瘤复发或新生而进行2～11次治疗。随访343例1年、2年和3年的生存率，HCC分别为87.7%，67.4%和56.8%，其中63例早期癌分别为92.9%，82.8%，74.5%；MLC分别为81.6%，50.8%，27.2%。本组并发症的发生率占2.4%（14/582人次），多发生于治疗中或治疗后即刻，主要为机械性损伤、热损伤等，分别为出血5例，肠穿孔1例，邻近脏器结构损伤5例，胆汁瘘2例，皮肤烫伤1例。结论：RFA作为一种肝肿瘤的局部微创治疗方法，对早期肝癌可获得手术治疗效果；对中晚期肝癌、肝癌术后复发、肝转移癌等临床治疗困难的病例，也可提供有效而相对安全的治疗手段。重视并发症的表现并采用相应的对症处理措施，可提高患者生存质量，延长生存期。

AIM: To investigate the treatment efficacy of radiofrequency ablation (RFA) of hepatic malignant tumor and the relevant complications. METHODS: A total of 338 patients with 763 hepatic tumors underwent ultrasound-guided RFA (565 procedures). There were 204 cases of hepatic cellular carcinoma (HCC) with 430 tumors, the mean largest diameter was 4.0cm. Of them, 48 patients (23.5%) were in stages I-II (UICC Systems) and 156 (76.5%) in stages III-IV There were 134 cases of metastatic liver carcinoma (MLC), with 333 metastases in the liver, the mean diameter was 4.1cm, the liver metastases of 96 patients (71.6%) came from gastrointestinal tract. Ninety-three percent of the 338 patients were treated using the relatively standard protocol. Crucial attention must be paid to monitor the abnormal changes in ultrasound images as well as the vital signs of the patients to find the possible hemorrhage and peripheral structures injury in time. The tumors were considered as ablated completely, if no viability was found on enhanced CT within 24 h or at 1 mo after RFA. These patients were followed up for 3-57 mo. RESULTS: The ablation success rate was 93.3% (401/430 tumors) for HCC and was 96.7% (322/333 tumors) for MLC. The local recurrence rate for HCC and MLC was 7.9% (34/430 tumors) and 10.5% (35/333 tumors), respectively. A total of 137 patients (40.5%) underwent 2-11 times of repeated ablations because of tumor recurrence or metastasis. The 1st, 2nd, and 3rd year survival rate was 84.6%, 66.6%, and 63.1%, respectively; the survival rate from 48 patients of I-II stage HCC was 93.7%, 80.4%, and 80.4%, respectively. The major complication rate in this study was 2.5% (14 of 565 procedures), which consisted of 5 hemorrhages, 1 colon perforation, 5 injuries of adjacent structures, 2 bile leakages, and 1 skin burn. CONCLUSION: RFA, as a minimally invasive local treatment, has become an effective and relatively safe alternative for the patients of hepatic malignant tumor, even of advanced liver tumor, tumor recurrence, and liver metastases. Knowledge about possible complications and their control may increase the treatment efficacy and help to promote the use of RFA technique.

PURPOSE: The purposes of this study were to investigate a treatment strategy to increase liver tumor necrosis and minimize complications with ultrasound-guided percutaneous radiofrequency (RF) ablation and to evaluate its therapeutic efficacy. MATERIALS AND METHODS: A total of 332 patients with 503 liver malignancies underwent RF ablation according to a mathematical protocol with adjunctive measures. In the 332 patients, 205 had 308 hepatocellular carcinomas (HCCs) with a mean largest diameter of 4.1cm and 127 had 195 metastatic liver carcinomas (MLCs) with a mean largest diameter of 3.9cm. In patients with HCC, 60 (29.3%) had stage I/II disease and 145 (70.7%) had stage III/IV disease. Depending on tumor size, shape, and location, a defined treatment strategy was adopted that consisted of a mathematical protocol, an individualized protocol, and adjunctive measures. The mathematical protocol was followed for tumors larger than 3.5cm. The individualized protocol was used for tumors located adjacent to the diaphragm, gastrointestinal tract, or gallbladder. Some adjunctive measures such as supplementary fine needle localization, local saline solution injection, and feeding vessel ablation were used to deal with different features of these liver tumors. Patients were followed regularly to assess treatment efficiency, and the tumor was considered to have early complete necrosis if no viability was found on enhanced computed tomography 1 month after RF ablation. RESULTS: In this series, the early necrosis rates were 95.8% for HCC (295 of 308 tumors), 94.9% for MLC (185 of 195 tumors), 91.3% for tumors larger than 3.5cm (189 of 207 tumors), 90.7% for tumors near the gastrointestinal tract (49 of 54 tumors), 91.5% for tumors near the diaphragm (86 of 94 tumors), and 90.6% for tumors near the gallbladder (48 of 53 tumors). The local recurrence rates were 10.7% for HCC (33 of 308 tumors) and 14.9% for MLC (29 of 195 tumors). The 1-, 2-, and 3-year overall survival rates were 89.6%, 69.4%, and 59.6%, respectively, for HCC and 80.3%, 52.8%,and 30.9%, respectively, for MLC. The 1-, 2-, and 3-year survival rates in 60 patients with stage I/II HCC were 93.7%, 87.1%, and 76.2%, respectively. The incidence of major complications was 1.4% (eight of 574 sessions), which included of three hemorrhages, four injuries to adjacent structures, and one case of needle tract seeding. CONCLUSION: In RF ablation of hepatic tumors, application of a proper protocol and adjunctive measures play important roles in improving tumor necrosis rate and minimizing potential complications.

Background The advent of second generation agent-SonoVue arid low mechanical index real-time contrast enhanced uhrasonography (CEUS) imaging have been shown to improve the diagnostic performance of ultrasonography in hepatocellular carcinoma (HCC). But no report has described the effect of high mechanical index (MI) post-CEUS This study aimed to investigate the value of post-CEUS in displaying tissue structures of HCC. Methods Seventy-six HCCs in 65 patients were included in the study Each patient undm~ent three scans, high-MI (MI: 0.15-1.6) pre-contrast ultrasound, low-MI (Mi: 0.04-0.08) CEUS with contrast agent SonoVue, and high-MI post-contrast ultrasound, which was performed within 3 minutes after CEUS The size, boundary, echogenicity, internal echotexture arid posterior acoustic enhancement of the HCCs in the conventional scans before and after CEUS were evaluated According to pathological evidence, diagnosis rates of pre-contrast, CEUS arid post-contrast scans were determined arid compared The potential mechanism of post-contrast ultrasound imaging was also discussed. Results Compared with pre-contrast, post-contrast ultrasound showed improvement in image quality in most HCCs: twenty-six (34.2%) more lesions showed well defined margins and fourteen (18.4%) more nodules showed halo sign; twenty-three (30.3%) lesions demonstrated enlarged in sizes; changes in echogenicity were seen in 30 lesions(39.5%): eighteen(23.7%) more lesions showed heterogeneeity and 20 (26.3%) more lesions showed "mosaic" or "nodule-in-nodule" sign: twelve (15.8%) more lesions showed posterior acoustic enhancement Post-contrast ultrasound showed increased diagnostic accuracy of 93.4% (71/76), compare with 88.2% (67/76) of CEUS alone. Conclusions High-MI post-contrast ultrasound utilizes harmonic signals during the rupture of microbubbles, and significantly improves the display of echo-characteristics of HCCs in ultrasound images, which adds diagnostic values for CEUS Post-contrast ultrasound could play an important role in tissue characterization, and may be included in CEUS protocols.