Laser-enhanced particle-free HIFU heating

描述(申请人提供)：高强度聚焦超声(HIFU)治疗已经成为实体肿瘤治疗的一种真正的非侵入性医疗程序。然而，单次HIFU超声后的病变体积很小。因此，切除一个相对较小的肿瘤可能需要长达数小时的时间。此外，由于血液循环的降温效应，高血管(灌流)组织比低灌注区更耐热消融。因此，在高度血管化的组织中，需要延长加热时间。皮肤烧伤，通常局限于亚厘米的表面烧伤，也经常在HIFU治疗后观察到，因为超声波能量沉积在皮肤表面达到局部最大值。为了促进HIFU过程，避免或最大限度地减少皮肤烧伤，我们需要在相对较低的超声强度水平加强HIFU在目标组织中诱导的加热。HIFU诱导加热的效果与局部超声吸收有关。增加靶组织对超声的吸收可有效改善HIFU治疗的加热效果。将超声造影剂或纳米颗粒注射到靶组织中作为一种增加局部超声吸收和增强HIFU加热的方法已被研究。在目前的项目中，我们建议评估一种光增强的无粒子技术，以促进HIFU消融。我们的中心假设是，HIFU治疗可以通过诊断性激光系统来改进，而不需要向体内注入任何微米或纳米粒子。我们有两个具体的目标：1)研究和优化光增强无粒子HIFU加热：体外研究；2)在啮齿动物模型中评估光增强无粒子HIFU加热。我们相信，拟议研究的成功将导致HIFU治疗实体肿瘤的增强，包括乳腺癌、前列腺癌和头颈癌的治疗。 与公共健康相关：拟议的研究将评估一种用于实体肿瘤治疗的光增强无颗粒高强度聚焦超声(HIFU)加热技术。这项新技术将通过使用诊断性激光系统来加强HIFU治疗，而不需要向体内注入任何微米或纳米粒子。这项拟议研究的成功将极大地改进目前的HIFU疗法。

DESCRIPTION (provided by applicant): High intensity focused ultrasound (HIFU) therapy has emerged as a truly non-invasive medical procedure for solid tumor treatment. However, the volume of the lesion following a single HIFU sonication is small. As a result, it can take up to several hours to ablate a relatively small tumor. In addition, highly vascularized (perfused) tissues are more resistant to thermal ablation than poorly perfused areas owing to the cooling effect of blood circulation. Therefore, a prolonged heating duration will be required in highly vascularized tissues. Skin burns, which are usually limited to subcentimetre superficial burns, are also often observed after HIFU treatments because ultrasonic energy deposition reaches a local maximal at skin surface. To facilitate HIFU process and avoid or minimize skin burns, we need to enhance HIFU-induced heating in the targeted tissue at a relatively low ultrasound intensity level. The effectiveness of HIFU-induced heating is related to the local ultrasound absorption. The increase of ultrasound absorption in the targeted tissue can effectively improve the heating outcome of HIFU treatment. The injection of ultrasound contrast agents or nanoparticles into the targeted tissue has been studied as a method to increase the local ultrasound absorption and enhance HIFU heating. In the current project, we propose to evaluate a photo-enhanced particle-free technique to facilitate HIFU ablation. Our central hypothesis is that HIFU therapy can be improved by a diagnostic laser system without the injection of any micro-, or nano-particles into the body. We have two specific aims: 1) investigate and optimize photo- enhanced particle-free HIFU heating: ex vivo study; and 2) evaluate photo-enhanced particle-free HIFU heating in a rodent model. We believe that the success of the proposed research will lead to an enhanced HIFU therapy for solid tumor treatments, which include the treatment of breast tumors, prostate tumors, head and neck cancer. PUBLIC HEALTH RELEVANCE: The proposed research will evaluate a photo-enhanced particle-free high intensity focused ultrasound (HIFU) heating technique for solid tumor treatment. This new technique will enhance HIFU therapy by using a diagnostic laser system and without injecting any micro-, or nano-particles into the body. The success of the proposed research will significantly improve the current HIFU therapy.