NEW ULTRASOUND PHASED ARRAY APPLICATORS FOR HYPERTHERMIA

体温过高，尤指与电离结合使用 放射治疗正在成为癌症治疗的一种可行的方式。一个 目前可用的临床数据中有很高比例是 用喷头获得，几乎不能控制加热 治疗体积内的图案。然而，这种控制是 获得最佳治疗温度所必需的 分布，特别是当血流量在 治疗。本提案讨论了几种新的相控阵 超声热疗敷贴器的概念， 基于广泛的初步研究，提供所需的 加热灵活性。将获得最佳的工程设计 通过涉及声场强度的计算机模拟 处理过程中的计算和温度分布 通过适当的热模型预测的体积。原型 基于优化设计的涂抹器将被制造和测试 论证可行性并提供技术基础 最终建造新的热疗系统。测试将会 涉及详细的野外模式测量、动物研究 涉及正常组织和肿瘤组织，以及初步临床试验。 初步研究已经导致了几种新的超声波敷贴器 概念，即同心环和扇形旋涡分阶段 数组。细分为扇区的同心环相控阵 (径向切片)通过适当的阶段化，可以产生不同的 直径为环形(或环形)焦点区域。这样的焦环可以是 如果在肿瘤周围定向，则有效加热肿瘤 外围设备。扫描焦环直径和焦距 提供相当大的加热灵活性。此外，适当的 环和扇区的阶段化可以产生如下图案 循环不对称的。通过控制这些不对称性， 非球形肿瘤的加热效果更佳。研究与实践 本文还提出了其他更高级的概念。

Hyperthermia, particularly when used in conjunction with ionizing radiation, is becoming a viable modality for cancer treatment. A high percentage of the clinical data currently available were obtained with applicators allowing little control of heating patterns within the treatment volume. However, such control is essential for obtaining therapeutically optimun temperature distributions, particularly when blood flow changes during treatment. This proposal discusses several new phased array concepts for ultrasound hyperthermia applicators which should, based on extensive preliminary studies, provide the needed heating flexibility. Optimun engineering designs will be obtained by computer simulation involving acoustic field intensity computations and temperature distributions in the treatment volume as predicted by appropriate thermal modeling. Prototype applicators based on optimal designs will be fabricated and tested to demonstrate feasibility and to provide the technical basis for eventual construction of new hyperthermia systems. Testing will involve detailed field pattern measurements, animal studies involving normal and tumor tissues, and preliminary clinical trials. Preliminary research has led to several new ultrasound applicator concepts, viz., the concentric-ring and sector-vortex phased arrays. Concentric-ring phased arrays subdivided into sectors (radial slices) can, with appropriate phasing, produce variable diameter annular (or ring) focal regions. Such focal rings can be effective in heating tumors if directed around the tumor periphery. Scanning the focal ring diameter and focal length provides considerable heating flexibility. Moreover, appropriate phasing of the rings and sectors can produce patterns which are circularly asymmetric. By controlling these asymmetries, nonspherical tumors can be heated more optimally. Research on other more advance concepts is also proposed herein.