肿瘤的超声波治疗

文中就超声波热疗,高强度聚焦超声以及低频超声波在肿瘤治疗中的应用进行了描述。早期主要是利用超声波的热效应来治疗肿瘤,近年来兴起的高强度聚焦超声是热疗法的另一发展。它瞬间使肿瘤组织温度升至65℃以上,导致靶区组织凝固和坏死来达到对肿瘤的“热切除”,是一种安全、有效的肿瘤治疗手段,具有无限潜力。尽管低频超声治疗肿瘤的机制尚不明了,但因其可以诱导细胞凋亡,为肿瘤的治疗提供了新的途径,其治疗作用已受到重视。     

高强度聚焦超声肿瘤治疗焦域的仿真研究

数值仿真是预测高强度聚焦超声(high intensity focused ultrasound,HIFU)治疗的温度分布、确定治疗剂量的有效方法之一。本研究采用Westervelt方程的近似式,并结合Pennes生物热传导方程,以猪肝肿瘤为例,在考虑肝组织声学特性对HIFU温度场影响的条件下,通过时域有限差分法仿真研究辐照时间和声强对肿瘤组织内可治疗焦域体积的影响。研究结果表明,一定声强条件下,肝组织声学特性对肿瘤内可治疗焦域的影响随着辐照时间的延长而凸显;可治疗焦域体积随时间增长或声强增大而非线性增加;相同辐照条件下,肿瘤组织内的可治疗焦域体积大于肝组织内的;当可治疗焦域体积一定时,辐照声强和辐照时间呈负相关;同时,等效热剂量判定的可治疗焦域大于温度阈值判定的可治疗焦域,且二者之差随声强而变化。     

肿瘤热疗的研究进展

肿瘤热疗是近年来研究的热点。肿瘤热疗后宿主机体的免疫功能发生变化,宿主全身抗肿瘤免疫反应被激活。本文从基础研究和临床试验两个方面对热疗后机体免疫功能的改变及其杀伤肿瘤的机理作一综述。     

高强度聚焦超声在治疗肝癌中的研究进展

肝癌是我国常见的恶性肿瘤之一,手术切除是治疗肝癌的首选治疗方法,但是大多数患者发现时多数为中晚期,无法进行手术切除.高强度聚集超声(HIFU)是一种非侵袭性的治疗方法,在肝癌的治疗中发挥着举足轻重的作用.为此作者对HIFU治疗肝癌的原理、提高免疫力的作用及抑制肝癌侵袭和转移的作用进行阐述,为临床治疗该病提供参考.     

高强度聚焦超声在治疗肝癌中的研究进展

肝癌是我国常见的恶性肿瘤之一,手术切除是治疗肝癌的首选治疗方法,但是大多数患者发现时多数为中晚期,无法进行手术切除。高强度聚集超声(HIFU)是一种非侵袭性的治疗方法,在肝癌的治疗中发挥着举足轻重的作用。为此作者对HIFU治疗肝癌的原理、提高免疫力的作用及抑制肝癌侵袭和转移的作用进行阐述,为临床治疗该病提供参考。     

高能聚焦超声在治疗晚期胰腺癌中的疗效分析

目的：通过对晚期胰腺癌患者行高强度聚焦超声治疗,观察其近期疗效,为晚期胰腺癌患者的临床治疗提供一种新的选择。方法：对15例晚期胰腺癌患者行高强度聚焦超声治疗,对比治疗前后的KPS评分,疼痛感受评分,CA199,三大常规,生化检查,B超观察肿瘤回声及血供,CT观察肿瘤大小改变。结果：HIFU治疗后,患者KPS评分升高,疼痛评分下降,肿瘤标志物下降,B超观察肿瘤回声,其中10例肿瘤回声增强,11例肿瘤血供减少或消失,CT示大部分患者治疗后肿瘤体积缩小或不变,治疗后三大常规、生化和电解质无明显改变。结论：运用高强度聚焦超声治疗晚期胰腺癌患者,在改善患者临床症状方面有明显疗效,并且能缩小肿瘤体积,减少或中断肿瘤血供,是一种很有发展前景的无创治疗方法。     

肿瘤热疗机制与方法的研究进展

本文主要从肿瘤热疗的生物学机制,肿瘤热疗的方法以及当前肿瘤热疗中存在的主要问题等方面综述了该领域的国内外研究进展．提出了其发展的主要方向。     

高强度聚焦超声治疗子宫肌瘤300例的临床疗效分析

目的：探讨高强度聚焦超声（high intensity focused ultrasound,HIFU）治疗子宫肌瘤的临床疗效及其安全性。方法：回顾性分析我院2007年1月～2011年1月300例采用高强度聚焦超声治疗的子宫肌瘤患者的临床资料,比较分析治疗前后瘤体大小、病灶内部回声、临床症状改善情况、血流的变化及超声造影图像改变。结果：HIFU治疗后1、3、6及12个月,瘤体体积均较治疗前显著缩小（P〈0.05）,显效率80.33%（241例）,有效率19.33%（58例）,无效率0.33%（1例）,肌瘤所致的临床症状减轻或消失,瘤体内部回声增强,彩色血流均消失,超声造影瘤体内无灌注。治疗期间,患者出现治疗部位疼痛、骶尾部酸胀及肛门坠胀,治疗结束时症状消失;治疗过程中出现腿部疼痛、麻木症状,经过重新定位后症状消失,少数出现阴道少量流血,给予止血药;治疗后出现血尿,经大量喝水排尿后消失。结论：HIFU治疗子宫肌瘤是安全有效的,在妇科领域便于推广。     

高强度聚焦超声治疗中测温技术的研究

高强度聚焦超声(HIFU)是一种新兴的非侵入性局部治疗技术,它以其治疗中安全、有效、无创的优点被医学界所关注.然而,对生物组织温度的准确测量是制约该治疗技术发展的关健环节,因此,HIFU治疗中的测温技术成为人们关注的热点.本文主要介绍了近年来在HIFU治疗中,测温技术的研究现状以及两大测温方法(无损测温和有损测温),并对测温技术的发展进行展望.     

吐温80 在深部脏器肿瘤热化疗中的应用研究

目的：研究热增敏剂吐温80在深部肿瘤热化疗中的临床应用疗效。方法：采用吐温80合并热化疗综合治疗晚期肿瘤118例,并与同时期未采用吐温80的热化疗组98例进行比较。膀胱癌复发5例,伴腹水、腹膜转移7例。小剂量化疗用5-FU、丝裂霉素、顺铂等行膀胱灌注或腹腔注射,吐温80浓度为0．2％。肿瘤射频热疗机,f：41MHz。平均随访时间36个月。结果：复发性膀胱癌完全缓解率达60％,血尿消失,3例在12～34月随访期间膀胱镜检查未复发;伴腹水者完全缓解率达85．7％（CR6／7）,中位生存期8．5月,腹痛、腹胀、便血等消失。治疗未引起恶心、呕吐等明显的消化道症状,肝、肾和骨髓功能损害。结论：在肿瘤的热化疗中。合用吐温80不仅可以降低化疗药物的剂量,而且降低热疗时的温度,减少毒副作用,改善症状和体征。     

The survival of amphibian embryos after continuous ultrasonic treatment

The effect of continuous ultrasonic treatment on the development of early embryos of common frog Rana temporaria was studied. Intact embryos at the blastula stage were exposed to ultrasound of various frequencies (0.88 and 2.64 MHz) and intensities (0.05 to 1.0 W/cm²) for various periods (1 to 15 min). The increase in ultrasound intensity to 0.7–1.0 W/cm² and exposure time to 5–15 min resulted in nearly complete mortality. Development of the embryos exposed to ultrasound of medium intensity (0.2–0.7 W/cm²) for 1–5 min was virtually similar to the control. Treatment at a frequency of 2.64 MHz and intensity of 0.05–0.7 W/cm² for 1–5 min had no effect on the development of amphibian embryos and their survival rate. The increase in intensity of the ultrasound of this frequency to 1 W/cm² and the exposure time to 5 min decreased the number of normally developing embryos by 35%.     

Rapid Detection of high-level oncogene amplifications in ultrasonic surgical aspirations of brain tumors

ABSTRACT: BACKGROUND: Genomic tumor information, such as identification of amplified oncogenes, can be used to plan treatment. The two sources of a brain tumor that are commonly available include formalin-fixed, paraffin-embedded (FFPE) sections from the small diagnostic biopsy and the ultrasonic surgical aspiration that contains the bulk of the tumor. In research centers, frozen tissue of a brain tumor may also be available. This study compared ultrasonic surgical aspiration and FFPE specimens from the same brain tumors for retrieval of DNA and molecular assessment of amplified oncogenes. METHODS: Surgical aspirations were centrifuged to separate erythrocytes from the tumor cells that predominantly formed large, overlying buffy coats. These were sampled to harvest nuclear pellets for DNA purification. Four glioblastomas, 2 lung carcinoma metastases, and an ependymoma were tested. An inexpensive PCR technique, multiplex ligation-dependent probe amplification (MLPA), quantified 79 oncogenes using 3 kits. Copy number (CN) results were normalized to DNA from non-neoplastic brain (NB) in calculated ratios, [tumor DNA]/[NB DNA]. Bland-Altman and Spearman rank correlative comparisons were determined. Regression analysis identified outliers. RESULTS: Purification of DNA from ultrasonic surgical aspirations was rapid (<3 days) versus FFPE (weeks) and yielded greater amounts in 6 of 7 tumors. Gene amplifications up to 15-fold corresponded closely between ultrasonic aspiration and FFPE assays in Bland-Altman analysis. Correlation coefficients ranged from 0.71 to 0.99 using 3 kit assays per tumor. Although normalized CN ratios greater than 2.0 were more numerous in FFPE specimens, some were found only in the ultrasonic surgical aspirations, consistent with tumor heterogeneity. Additionally, CN ratios revealed 9 high-level ([greater than or equal to] 6.0) gene amplifications in FFPE of which 8 were also detected in the ultrasonic aspirations at increased levels. The ultrasonic aspiration levels of these amplified genes were also greater than 6.0 CN ratio, except in one case (3.53 CN ratio). Ten of 17 mid-level ([greater than or equal to]3.0 & <6.0 CN ratio) amplifications detected in FFPE were also detected as being increased ([greater than or equal to] 2.0 CN ratio) in the aspirations. CONCLUSIONS: Buffy coats of centrifuged ultrasonic aspirations contained abundant tumor cells whose DNA permitted rapid, multiplex detection of high-level oncogene amplifications that were confirmed in FFPE. Virtual slides http://www.diagnosticpathology.diagnomx.eu/vs/1883718801686466.     

The ultrasonic picture of hypernephromas

For objective assessment of an ultrasound picture of the kidneys in tumors the authors compared the results of USI, angiography of the kidneys and the removed operative material. In 32 cases kidney tumors were hyperechogeneous, in 13 cases--medium echogeneous, and in 8 cases--hypoechogeneous. The authors detected no relationship between a degree of vascularization of the tumor and its echogeneous type. By their results hypernephromas can have a different echographic picture which may be determined by tumor macromorphology (the presence of necrosis, cystic cavities, etc.). Sizes of kidney tumors by USI findings were 10-15% less than true tumor sizes, and the determination of tumor borders based on USI findings, was rather difficult.     

Effect of ultrasonic treatment on the biochemphysical properties of chitosan

Four chitosans with different molecular weights and degrees of deacetylation degree and 28 chitosans derived from these initial chitosans by ultrasonic degradation have been characterized by gel permeation chromatography (GPC), FT-IR spectroscopy, X-ray diffraction and titrimetric analyses. Antimicrobial activities were investigated against E. coli and S. aureus using an inhibitory rate technique. The results showed that ultrasonic treatment decreased the molecular weight of chitosan, and that chitosan with higher molecular weight and higher DD was more easily degraded. The polydispersity decreased with ultrasonic treatment time, which was in linear relationship with the decrease of molecular weight. Ultrasonic degradation changed the DD of initial chitosan with a lower DD (<90%), but not the DD of the initials chitosan with a higher DD (>90%). The increased crystallinity of ultrasonically treated chitosan indicated that ultrasonic treatment changed the physical structure of chitosan, mainly due to the decrease of molecular weight. Ultrasonic treatment enhanced the antimicrobial activity of chitosan, mainly due to the decrease of molecular weight.     

Inactivation of Cryptosporidium parvum oocysts in water using ultrasonic treatment

Ultrasound in a liquid phase cause mass and heat transfer across the liquid through cavitational processes which act as nanoreactors to generate unstable mechanical equilibrium. The effect of 1 MHz ultrasound on the inactivation of Cryptosporidium parvum was investigated. Continuous irradiation of ultrasound (20 min) increased temperature due to cavitational phenomena. Ultrasound irradiation of liquid containing C. parvum showed significant quantitative changes in pH, temperature and inactivation of C. parvum (102.7 oocysts killed/s) with a minimum energy consumption (0.05 oocysts/s).     

Towards treatment planning and treatment of deep-seated solid tumors by electrochemotherapy

Background  

Electrochemotherapy treats tumors by combining specific chemotherapeutic drugs with an intracellular target and electric pulses, which increases drug uptake into the tumor cells. Electrochemotherapy has been successfully used for treatment of easily accessible superficial tumor nodules. In this paper, we present the first case of deep-seated tumor electrochemotherapy based on numerical treatment planning.