Extracorporeal High Intensity Focused Ultrasound Ablation in the Treatment of Patients with Large Hepatocellular Carcinoma

Background: High intensity focused ultrasound (HIFU) is a noninvasive treatment modality that induces complete coagulative necrosis of a deep tumor through the intact skin. The current study was conducted to determine the safety, efficacy, and feasibility of extracorporeal HIFU in the treatment of patients with hepatocellular carcinoma (HCC).Methods: A total of 55 patients with HCC with cirrhosis were enrolled in this prospective, nonrandomized clinical trial. Among them, 51 patients had unresectable HCC. Tumor size ranged from 4 to 14 cm in diameter with mean diameter of 8.14 cm. According to tumor, node, metastasis (TNM) classification, 15 patients corresponded to stage II, 16 to stage IIIA, and 24 to IIIC. All patients had HIFU, and the median number of HIFU session was 1.69. Safety and efficacy of HIFU were assessed in this trial.Results: No severe side effect was observed in the patients treated with HIFU. Follow-up imaging showed an absence of tumor vascular supply and the shrinkage of treated lesions. Serum -fetoprotein returned to normal level in 34% of patients. The overall survival rates at 6, 12, and 18 months were 86.1%, 61.5%, and 35.3%, respectively. The survival rates were significantly higher in patients in stage II than those in stage IIIA (P = .0132) and in stage IIIC (P = .0265).Conclusion: As a noninvasive therapy, HIFU appears to be effective, safe, and feasible in the treatment of patients with HCC. It may play an important role in the ablation of large tumors.     

射频消融在骨肿瘤中的应用及研究进展

射频消融(RFA)是一种安全、有效的微创治疗方法,已普遍应用于原发性肝癌和肝转移瘤的临床治疗中。近年来被初步应用到骨肿瘤的临床治疗中,用于治疗骨样骨瘤和缓解失去手术机会的骨转移瘤所致的疼痛,并可与其他治疗方法联合应用。在此对临床上RFA治疗骨肿瘤的应用范围、治疗效果,RFA的基本原理,对骨行RFA时消融针周围的热场分布情况及形态,消融灶的损毁范围及其影响因素进行综述。     

高血压肾病患者尿电导率与渗透压的相关性分析

目的 观察高血压肾病患者的尿液电导率和尿液渗透压的变化,并探讨两者之间的相关性.方法 采用UF-1000i全自动尿沉渣分析仪与渗透压仪分别测定85例临床确诊高血压肾病患者和98例健康体检者(对照组)晨尿的电导率和渗透压值,并对结果进行统计学分析.结果 高血压肾病组患者尿液电导率和渗透压分别为(11.64 ± 3.68) mS/cm和(352.45 ± 91.22) mOSM/kgH2O,均低于对照组的(17.58 ± 4.35) mS/cm和(557.11±131.70) mOSM/kgH2O,差异均有显著统计学意义(P<0.01);两组受检者的尿液电导率与渗透压相关性系数r分别为0.823和0.939,直线回归方程分别是Y=24.01X+73.01和Y=33.13X-25.52.结论 尿液电导率变化可以反映尿液渗透压的变化,能够更加快速地监测高血压肾病患者肾脏浓缩稀释功能.     

MR引导下高强度聚焦超声消融子宫肌瘤温度曲线参数与治疗效果的关系

目的观察MR引导下高强度聚焦超声(HIFU)消融子宫肌瘤温度曲线参数与治疗效果的关系。方法对31例子宫肌瘤患者行MR引导下高强度聚焦超声消融子宫肌瘤,通过HIFU消融子宫肌瘤过程中的热量分布情况获得温度曲线,然后利用Matlab语言编程计算以下温度曲线参数:温度上升斜率、温度下降斜率、曲线下面积、加热时间、最高平均温度和温度达峰时间。应用Spearman秩相关性检验分析HIFU治疗前与治疗后6个月子宫肌瘤体积变化与治疗过程中温度曲线参数的关系。结果治疗后6个月,子宫肌瘤体积平均缩小率为(39.43±27.01)%;子宫肌瘤HIFU消融过程中,温度曲线示温度上升斜率为(0.97±0.84)℃/s,温度下降斜率为(-0.56±0.39)℃/s,曲线下面积为(2 240.03±455.93)℃·s,加热时间为(28.34±12.88)s,最高平均温度为(47.01±4.63)℃,温度达峰时间为(22.79±9.47)s。温度下降斜率与子宫肌瘤体积缩小率呈正相关(r_s=0.473,P=0.007)。结论 MR引导下HIFU消融后子宫肌瘤温度下降越慢,治疗效果越好。     

Combination of transurethral and interstitial ultrasound applicators for high-temperature prostate thermal therapy

The purpose of this study was to determine the feasibility of using a transurethral ultrasound applicator in combination with implantable ultrasound applicators for inducing thermal coagulation and necrosis of localized cancer lesions or benign disease within the prostate gland. The potential to treat target zones in the anterior and lateral portions of the prostate with the angularly directive transurethral applicator, while simultaneously treating regions of extracapsular extension and zones in the posterior prostate with the directive implantable applicators in combination with a rectal cooling bolus, is evaluated. Biothermal computer simulations, acoustic characterizations, and in vivo thermal dosimetry experiments with canine prostates were used to evaluate the performance of each applicator type and combinations thereof. Simulations have demonstrated that transurethral applicators with 180-270° acoustic active zones can direct therapeutic heating patterns to the anterior and lateral prostate, implantable needles can isolate heating to the posterior gland while avoiding rectal tissue, and that the combination of applicators can be used to produce conformal heating to the whole gland. Single implantable applicators (1.8mm ODx10mm long, ～180° active sector, ～7MHz, direct-coupled type) produced directional thermal lesions within in vivo prostate, with temperatures &gt;50°C extending more than 10mm radially after 10-15min. Combination of interstitial applicators (1-2) and a transurethral applicator (3-2.5mm ODx6 mm long, 180° active sector, 6.8MHz, 6 mm OD delivery catheter) produced conforming temperature distributions (48-85°C) and zones of acute thermal damage within 15min. The preliminary results of this investigation demonstrate that implantable directional ultrasound applicators, in combination with a transurethral ultrasound applicator, have the potential to provide thermal coagulation and necrosis of small or large regions within the prostate gland, while sparing thermally sensitive rectal tissue.     

New standards for devices used for the measurement of human body temperature

Significant changes in recording of human body temperature have been taking place worldwide in recent years. The clinical thermometer introduced in the mid-19th century by Wunderlich has been replaced by digital thermometers or radiometer devices for recording tympanic membrane temperature. More recently the use of infrared thermal imaging for fever screening has become more widespread following the SARS infection, and particularly during the pandemic H1N1 outbreak. Important new standards that have now reached international acceptance will affect clinical and fever screening applications. This paper draws attention to these new standard documents. They are designed to improve the standardization of both performance and practical use of these key techniques in clinical medicine, especially necessary in a pandemic influenza situation.     

Echo Decorrelation Imaging of Rabbit Liver and VX2 Tumor during In Vivo Ultrasound Ablation

In open surgical procedures, image-ablate ultrasound arrays performed thermal ablation and imaging on rabbit liver lobes with implanted VX2 tumor. Treatments included unfocused (bulk ultrasound ablation, N = 10) and focused (high-intensity focused ultrasound ablation, N = 13) exposure conditions. Echo decorrelation and integrated backscatter images were formed from pulse-echo data recorded during rest periods after each therapy pulse. Echo decorrelation images were corrected for artifacts using decorrelation measured prior to ablation. Ablation prediction performance was assessed using receiver operating characteristic curves. Results revealed significantly increased echo decorrelation and integrated backscatter in both ablated liver and ablated tumor relative to unablated tissue, with larger differences observed in liver than in tumor. For receiver operating characteristic curves computed from all ablation exposures, both echo decorrelation and integrated backscatter predicted liver and tumor ablation with statistically significant success, and echo decorrelation was significantly better as a predictor of liver ablation. These results indicate echo decorrelation imaging is a successful predictor of local thermal ablation in both normal liver and tumor tissue, with potential for real-time therapy monitoring.     

微波热凝固治疗肝癌临床观察

目的:用频率为2450MHZ微波治疗机,14G深部组织间插入型电极,超声引导下经皮穿刺,微波热凝固治疗肝癌30例,观察疗效。方法:肿瘤直径3cm以下单结节型15例,3cm以上多发15例,微波功率60W每次60s,使电极尖端部2.5X1.5cm范围内可凝固坏死。3cm以下2～5次。3cm以上反复多次,直至完全凝固坏死。经增强CT评价坏死范围。根据坏死率(TN),缩小率(TR)判定疗效。结果:坏死率显效46.6%(14例),有效93%(28例)。缩小率有效21例(70%),肿瘤局部得以良好控制。结论:如配合肝动脉拴塞(TAE),肝动脉注药(TAI)治疗,可减少残存,控制复发,进一步提高疗效。     

Characteristics of the control of human thermoregulatory behavior

The aim of this study was to characterize several of the thermal input(s) that influence thermo-behavior in humans. Eight male subjects completed two trials in which they were free to initiate an exit from a hot chamber (45 °C) to a cold chamber (10 °C; H → C) or from a cold chamber to a hot chamber (C → H). Upon initiating an exit from the chamber, mean skin temperature (T_Sk), rectal temperature (T_Rectal), subjective thermal comfort, and time in the climate chambers prior to exit were recorded. Thermo-behavior was defined as the initiation of exit. All variables were similar (P ≥ 0.05) between the two trials. T_Sk and thermal comfort at H → C were significantly (P ≤ 0.05) higher (34.0 ± 1.1 °C, and 7.3 ± 0.6, respectively) than at C → H (29.4 ± 0.9 °C, and 3.0 ± 0.6, respectively). No significant differences (P ≥ 0.05) were found between H → C and C → H for T_Rectal (H → C: 37.0 ± 0.2 °C vs. C → H: 37.0 ± 0.2 °C) or time prior to exit (H → C: 3.9 ± 2.3 min vs. C → H: 3.9 ± 1.7 min). The frequency distributions and the probability of the initiation of exit curves at H → C and C → H for both T_Sk and thermal comfort were significantly negatively skewed (P ≤ 0.05) and normally distributed, respectively (P ≥ 0.05). Skin temperature appears to be an important thermal input mediating thermo-behavioral responses. This behavioral response appears to be more precise when exposed to hot temperatures compared to cold temperatures.