超声引导下射频消融治疗肝癌的临床价值

目的：探讨超声引导下多极射频介入治疗肝癌的临床价值。方法：19例肝癌患者26枚结节在超声引导下进行射频消融治疗，采取由深到浅，多点多部位，重叠消融的治疗原因，结果：12个结节（46．2％）缩小，肿瘤回声均增强16个（61．5％）血流信号减少或消失；病检8例阴性（8／12）；10例甲胎蛋白下降（10／13）；7例（7／13）肝功能改善，结论：超声引导下多电极射频治疗肝癌是一种疗效确切，操作简便，损伤小，安全性高的有效方法。     

射频热凝家兔肝组织的热效应观察

目的研究射频热凝家兔肝组织的热效应范围，并观察肝细胞、肝内动脉、静脉及胆管组织的损伤情况。方法将40只家兔随机分为2组（实验组与对照组，每组20只），均分别剖腹暴露肝脏，于实验组家兔肝膈面插入射频针并给予射频热凝处理，对照组家兔手术操作与实验组相同，但不给予射频热凝处理。2组家兔分别于术后1，5，10，15d各处死5只，取肝脏不同部位进行常规切片染色，观察肝细胞、动脉、静脉及胆管组织的损伤情况。采用TUNEL法检测肝细胞、胆管上皮细胞的凋亡率，并测定家免术前、术后血清GPT、T-BIL及D-BIL水平。结果通过组织学观察，发现该射频热凝治疗仪（单电极）对家兔肝组织的最大热效应损伤半径为2．5cm，在坏死区域内可见肝细胞、血管及胆管等均有程度不一的损伤。距凝固坏死区外边缘2、0cm范围内的肝细胞、胆管上皮细胞的凋亡指数均高于对照组相应部位细胞，差异有统计学意义（P〈0.01）；另外还发现实验组家兔肝细胞的凋亡指数也高于同区域胆管上皮细胞凋亡指数（P〈0．01）。结论对射频热效应耐受性由高至低排列依次为：胆管〉动脉〉静脉〉肝细胞，正常家兔肝细胞对射频热效应的敏感性大于胆管上皮细胞，细胞凋亡可能与射频热效应相关，即射频热凝能引发肝细胞、胆管上皮细胞凋亡。     

射频和自体肿瘤疫苗联合治疗肝癌临床研究

目的:探讨射频(RF)和新城鸡瘟病毒(NDV)修饰自体肿瘤疫苗(ATV)联合治疗肝癌效果。方法:治疗组28例进行RF联合ATV-NDV治疗,对照组22例进行RF治疗。RF共治疗50例75个瘤体,其中3个瘤体8例,2个瘤体9例。术中切取肿瘤组织,进行免疫测定、病理检查,治疗组加作ATV- NDV制备。根据瘤体大小设计射频治疗靶点,实施治疗。结果:RF治疗15d后75个瘤体57个完全坏死,12瘤体仅部分坏死,6例囊性变。两组治疗前AFP升高者治疗后降至正常。治疗组治疗后2月 CD4 降低、NK、CD3 、CD4 /CD8 升高,生存率1、3、5年分别为72．2％、50．1％、40.4％,对照组为 60．5％、43．6％、29．8％。结论:RF联合ATV-NDV治疗肝癌瘤体缩小、AFP下降、免疫功能提高均较单纯RF治疗快,生存率提高,可能与ATV-NDV应用延迟肿瘤复发有关。     

射频疗法用于晚期恶性肿瘤化疗患者临床分析

目的探讨射频疗法用于晚期恶性肿瘤化疗患者的治疗效果。方法240例晚期恶性肿瘤患者完全随机分为2组,对照组117例只采用化疗治疗方法,观察组123例,在对照组的基础上增加射频透热治疗,每周热疗1～2次,2次热疗间隔时间大于72h,8—10次热疗为1个疗程。比较2组患者的疗效及药物不良反应。结果观察组完全缓解8例;部分缓解18例,稳定74例,有效率为21．1％;对照组完全缓解4例,部分缓解10例,稳定63例,有效率为11．97％。2组差异有统计学意义。结论热疗与化疗结合治疗比单纯化疗的疗效较好,多数肿瘤患者临床症状明显改善。     

Differentiation of benign periablational enhancement from residual tumor following radio-frequency ablation using contrast-enhanced ultrasonography in a rat subcutaneous colon cancer model

Benign periablational enhancement (BPE) response to thermal injury is a barrier to early detection of residual tumor in contrast enhanced imaging after radio-frequency (RF) ablation. The objective of this study was to evaluate the role of quantitative of contrast-enhanced ultrasound (CEUS) in early differentiation of BPE from residual tumor in a BD-IX rat subcutaneous colon cancer model. A phantom study was first performed to test the validity of the perfusion parameters in predicting blood flow of two US contrast imaging modes-contrast harmonic imaging (CHI) and microflow imaging (MFI). To create a simple model of BPE, a peripheral portion of the tumor was ablated along with surrounding normal tissue, leaving part of the tumor untreated. First-pass dynamic enhancement (FPDE) and MFI scans of CEUS were performed before ablation and immediately, 1, 4 and 7 days after ablation. Time-intensity-curves in regions of BPE and residual tumor were fitted to the function y = A(1-exp[-β{t-t0}])+C, in which A, β, t0 and C represent blood volume, flow speed, time to start and baseline intensity, respectively. In the phantom study, positive linear correlations were noted between A, β, Aβ and contrast concentration, speed and flow rate, respectively, in both CHI and MFI. On CEUS images of the in vivo study, the unenhanced ablated zone was surrounded by BPE and irregular peripheral enhancement consistent with residual tumor. On days 0, 4 and 7, blood volume (A) in BPE was significantly higher than that in residual tumor in both FPDE imaging and MFI. Significantly greater blood flow (Aβ) was seen in BPE compared with residual tumor tissue in FPDE on day 7 and in MFI on day 4. The results of this study demonstrate that qualitative CEUS can be potentially used for early detection of viable tumor in post-ablation assessment.     

Percutaneous ethanol injection and radio-frequency ablation for the treatment of nonresectable colorectal liver metastases – techniques and results

Background: Percutaneous ethanol injection (PEI) and radio-frequency (RF) ablation are possible palliative treatment modalities for patients with non-resectable liver metastases of colorectal carcinomas. The different techniques are explained and reviewed. Results: PEI did not show promising results for the treatment of liver metastases. RF results were more encouraging; some studies showed improved mean survival times for patients when a complete necrosis of the metastases could be achieved. The maximum diameter of the necrotic area possible in a single session is about 5 cm. Conclusion: PEI and RF are palliative last-line treatment strategies for patients with non-resectable liver metastases and should only be applied if chemotherapy is not sufficient or not possible. The long-term efficacy of RF ablation in this group of patients has to be evaluated. Received: 10 March 1999 Accepted: 29 June 1999     

多弹头射频治疗肝癌36例报告

目的：探讨多弹头射频治疗肝癌的临床近期疗效。方法：对３６例肝癌患者进行射频治疗,通过对手术前后ＣＴ、Ｂ超检查的比较及ＡＦＰ、肝功能、机体免疫力、体重和自觉症状的改变进行对比观察。结果：３６例于治疗后７ｄ、１０例于治疗后３０ｄ经Ｂ超及ＣＴ检查;７ｄ后８０．６％的病人肿瘤体积缩小了３０％以上,３０ｄ后１０例病人肿瘤体积缩小了４０％以上,与术前相比瘤体内血供消失。８３．４％的病人自觉症状改善,ＡＦＰ值下降者占７７．８％,肝功能酶谱及胆红素均恢复正常,白蛋白平均增加１１．０ｇ．Ｌ＾－１。体重增加５．６ｋｇ,Ｔ淋巴细胞转化率平均增加２１％。ＩｇＧ平均增加２．０ｇ．Ｌ＾－１,无手术死亡。结论：多弹头射频治疗肝癌的适应证广、安全可靠、疗效满意。     

利用超声引导射频治疗功能性子宫出血

目的采用超声引导下射频消融法治疗功能性子宫出血,探讨非手术的微创技术治疗功能性子宫出血的优点。方法超声扫查以子宫纵切面为主,辅以横切面,正确引导自凝刀安全、准确进入子宫腔,观察子宫内膜回声变化。结果本组36例患者中,31例治疗后出血时间明显缩短。结论无创性射频治疗功能性子宫出血有很好的治疗效果。     

Intraoperative ultrasound score to predict recurrent hepatocellular carcinoma after radical treatments

Despite the high complete necrosis rate of radio-frequency ablation (RFA) or the complete removal following curative hepatic resection (HR), recurrent hepatocellular carcinoma (HCC) remains a significant problem. The aim of the study is to identify some intraoperative ultrasound (IOUS) patterns, predicting intrahepatic recurrences. From January 1997 to July 2009, 410 patients with HCC were treated (162 HR and 248 RFA through a surgical access). All patients were submitted to IOUS examination: 148 IOUS were performed during the laparotomic access while 262 IOUS were performed during the laparoscopic access. Primary HCC was classified according to diameter, HCC pattern (nodular or infiltrative), echogenicity (hyper- or hypo-echoic), echotexture (homogeneous or inhomogeneous), capsular invasion, mosaic pattern, nodule in nodule aspect and infiltration of portal vessels. Number of HCC nodules was also considered. Multivariate analysis (Cox model) was performed to determine features associated with recurrent HCC using IOUS patterns that independently predicted recurrent HCC, a IOUS score was developed. The patients were followed for 3-127 months, (median follow-up: 21.5 months). In 220 patients (54%), intrahepatic recurrences occurred. In 155 patients (38%), distant intrahepatic recurrences arose in different segments at the primary tumor site. In 65 HCC cases (16%), local recurrences were found. At multivariate analysis, multiple nodules, HCC diameter (>20 mm), HCC pattern (infiltrative), hyperechoic nodule and portal infiltration were statistically significant for risk factor of intrahepatic recurrences. Therefore, a IOUS scoring system was calculated on the basis of multivariate analysis and identified three risk categories of patients: in group 1 recurrences occurred in 37%, group 2 in 46% and group 3 in 66% (p = 0.0001). IOUS is an accurate staging tool during “surgical” procedures. This study showed an added value of IOUS: it permitted to identify ultrasound patterns, which can predict the risk of HCC recurrences. The calculated IOUS score permits to intraoperatively evaluate the actual surgical choice and to program the best treatment strategies during the follow-up period. (E-mail: rsantambrogio@mclink.it)     

Monitoring radio-frequency thermal ablation with ultrasound by low frequency acoustic emissions--in vitro and in vivo study

The object of this study was to evaluate the monitoring of thermal ablation therapy by measuring the nonlinear response to ultrasound insonation at the region being treated. Previous reports have shown that during tissue heating, microbubbles are formed. Under the application of ultrasound, these microbubbles may be driven into nonlinear motion that produces acoustic emissions at sub-harmonic frequencies and a general increase of emissions at low frequencies. These low frequency emissions may be used to monitor ablation surgery. In this study, a modified commercial ultrasound system was used for transmitting ultrasound pulses and for recording raw RF-lines from a scan plane in porcine (in vitro) and rabbit (in vivo) livers during radio-frequency ablation (RFA). The transmission pulse was 15 cycles in length at 4 MHz (in vitro) and 3.6 MHz (in vivo). Thermocouples were used for monitoring temperatures during the RFA treatment.In the in vitro experiments, recorded RF signals (A-lines) were segmented, and the total energy was measured at two different frequency bands: at a low frequency band (LFB) of 1-2.5 MHz and at the transmission frequency band (TFB) of 3.5-4.5 MHz. The mean energy at the LFB and at the TFB increased substantially in areas adjacent to the RF needle. These energies also changed abruptly at higher temperatures, thus, producing great variance in the received energy. Mean energies in areas distant from RF needle showed little change and variation during treatment. It was also shown that a 3 dB increase of energy at the low frequency band was typically obtained in regions in which temperature was above 53.3 ± 5°C. Thus, this may help in evaluating regions undergoing hyperthermia. In the in vivo experiments, an imaging algorithm based on measuring the LFB energy was used. The algorithm performs a moving average of the LFB energies measured at segments within the scan plane.Results show that a colored region is formed on the image and that it is similar in size to a measurement of the lesion from gross pathology, with a correlation coefficient of 0.743. (E-mail: Itai.Winkler@RKDiagnostics.co.il)