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Thermal Ablation and Free Radicals induction by Focused Ultrasound as tool for Cancer Therapy

聚焦超声热消融和自由基诱导作为癌症治疗工具

基本信息

批准号：
08407029
负责人：
ASANO Takehide
金额：
$ 25.79万
依托单位：
Chiba University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (A)
财政年份：
1996
资助国家：
日本
起止时间：
1996 至 1999
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-08407029/
关键词：
High Intensity Focused Ultrasound Active Oxygen Photo Sensitizer Thermal Ablation Liver Tumor Minimally Invasive Therapy Liver Surgery Acoustic Surgery High Intensity Focused Ultra sound Thermal Ablation Liver Tumor Minimally Invasiv

项目摘要

Focused Ultrasound has the potential ability to ablate selective tissue targets without damaging the intervening tissues between the transducer and target areas.We have studied this technique from the following two point of view.1) Fundamental studies on cancer therapy utilizing active oxygen that arises in ultrasonic field.The measurement by ESR proved the production of hydroxyl radical and singlet oxygen by the ultrasonic cavitation. The ultrasound field with the radical productivity activated pre-medicated photo sensitizer, and that it strengthens the tumoricidal effect in does dependent fashion. This tumoricidal effect was suppressed by the ascorbic acid, which has potential of radical scavenger. The tumor growth of the mouse experimental model was also suppressed by this combination. The combined use of photo sensitizer and focused ultrasound can be expected as a new minimally invasive therapy for the tumor which is not adequate photo-dynamic therapy since it located further depth than photo can reach.2) Thermal ablation by High intensity Focused Ultrasound (HIFU) as a tool for cancer therapyWhen the focusing ultrasonic energy is further strengthened focused area become thermal ablation. Continuous irradiation of focused ultrasound causes cavitation in the targeted region, creating microbubbles. It impairs the ultrasound to reach on the target area. We have developed an irradiation device with a new technique called the CAST, aimed at controlling the occurrence of microbubbles, which combined single frequency waves and frequency modulation. A devise with CAST can be more correctly conducted ablation with predetermined size and spatial location without damaging to surrounding tissues. It could also ablate the target area of rabbit and pig liver, precisely.An attractive thermal ablation method, HIFU would become a main therapeutic modality for liver, pancreas, and breast cancers in 21 century.

聚焦超声具有在不损伤换能器和靶区之间的组织的情况下消融选择性组织靶的潜在能力。我们从以下两个角度研究了这项技术。1）利用超声场中产生的活性氧进行癌症治疗的基础研究。ESR测量证实了超声空化产生羟基自由基和单线态氧。具有自由基产生能力的超声场可激活预处理光敏剂，并以剂量依赖方式增强其杀瘤作用。抗坏血酸具有潜在的自由基清除剂的作用，抑制了这种杀肿瘤作用。小鼠实验模型的肿瘤生长也被该组合抑制。光敏剂和聚焦超声的联合应用有望成为一种新的微创治疗肿瘤的方法，因为它位于比光所能到达的更深的深度，而光动力治疗是不够的。2）高强度聚焦超声（HIFU）热消融作为癌症治疗的工具当聚焦超声能量进一步增强时，聚焦区域成为热消融。聚焦超声的连续照射在目标区域中引起空化，产生微泡。它会妨碍超声波到达目标区域。我们已经开发了一种具有称为CAST的新技术的辐照装置，旨在控制微泡的发生，该技术结合了单频波和频率调制。具有CAST的装置可以更准确地进行预定尺寸和空间位置的消融而不损伤周围组织。高强度聚焦超声（HIFU）作为一种极具吸引力的热消融技术，将成为世纪肝癌、胰腺癌和乳腺癌的主要治疗手段。