High-resolution ultrasonic imaging of dose distribution in clinical gel dosimeter

描述（由申请人提供）：标题：临床凝胶剂量计中剂量分布的高分辨率超声成像短标题：剂量分布的超声成像项目总结Luna Innovations与Caribbean Health System合作，拟开发和测试一种高分辨率超声技术，用于临床凝胶剂量计中吸收剂量分布的非侵入性3D表征。辐射诱导的凝胶性能退化是一种有效的方法来捕捉空间剂量分布，可以通过后处理来揭示。存储3D剂量信息的能力明显优于传统的剂量测定技术，例如水量热法、离子室和基于薄膜的方法。然而，目前部署的使用磁共振成像和光学断层扫描的后处理方法价格昂贵，并且需要漫长的非现场处理。所提出的方法基于精确的超声信号相位测量技术，该技术可以检测由材料特性变化引起的声速变化，精度优于十亿分之二十。它将提供低成本，近实时，现场解释存储在凝胶中的剂量信息，具有非常高的空间分辨率和剂量精度。在第一阶段，我们将组装一个概念验证的超声扫描系统，准备凝胶样品与剂量分布记忆，并收集超声通过传输信号，根据扇形束断层扫描的几何形状在几个定制的凝胶样品电离辐射在临床环境中。我们将重建吸收剂量的空间分布，并将其与传统的扫描离子室技术测量的实际剂量进行比较。我们还将研究该方法的空间分辨率和剂量敏感性，以及其正确处理折射和边界过渡伪影的能力。在第二阶段，我们将开发一个基于圆形换能器阵列的便携式原型用于临床测试，并优化用于超声评估的辐射敏感凝胶的配方。一个基于阵列的原型将允许快速成像的剂量分布在标准化凝胶样品与最少的设备-可能是一个单一的盒子与USB连接到笔记本电脑。这项新技术将满足现代放射治疗设备快速准确的现场校准需求，从而提高未来癌症治疗程序的吞吐量和效率。职务名称：临床凝胶剂量计中剂量分布的高分辨率超声成像短标题：剂量分布的超声成像相关性：聚合物凝胶体模中吸收剂量的拟议超声表征将使现代放射治疗设备的快速和准确的现场校准成为可能，并有助于提高未来癌症治疗程序的通量和疗效。最终目标是提供真实的时间内精确的光束轮廓测量，以交互式地调整多叶准直器设置。

DESCRIPTION (provided by applicant): Title: High-resolution ultrasonic imaging of dose distribution in clinical gel dosimeters Short title: Ultrasonic imaging of dose distribution Project summary Luna Innovations in partnership with Carilion Health System proposes to develop and test a high-resolution ultrasonic technique for non-invasive 3D characterization of absorbed dose distributions in clinical gel dosimeters. Radiation-induced degradation of gel properties is an efficient way to capture spatial dose distribution that can be revealed via post processing. The ability to store 3D dose information is a clear advantage over conventional dosimetry techniques, such as water calorimetry, ion chambers, and film-based methods. However, currently deployed post-processing methods using magnetic resonance imaging and optical tomography are expensive and require lengthy off-site processing. The proposed method is based on accurate ultrasonic signal phase measurement technology that can detect changes in sound speed caused by variations in material properties with better than 20 parts per billion precision. It will offer low-cost, near-real-time, on-site interpretation of dose information stored in gel with very high spatial resolution and dose accuracy. In Phase I we will assemble a proof-of concept ultrasonic scanning system, prepare gel samples with dose distribution memory, and collect ultrasonic through-transmission signals according to the fan beam tomographic geometry on several custom gel samples subjected to ionizing radiation in clinical environment. We will reconstruct spatial distributions of absorbed dose and compare them to the actual dose measured with a conventional scanning ion chamber technique. We will also study the spatial resolution and dose sensitivity of the method as well as its ability to correctly handle refraction and boundary transition artifacts. In Phase II we will develop a circular transducer array-based portable prototype for clinical testing and optimize formulation of a radiation sensitive gel for ultrasonic assessment. An array-based prototype will allow for rapid imaging of dose distribution in standardized gel samples with minimum of equipment - potentially a single box with USB link to a laptop. The new technology will address the need for quick and accurate on-site calibration of modern radiation treatment equipment, resulting in increased throughput and efficiency of future cancer treatment procedures. Title: High-resolution ultrasonic imaging of dose distribution in clinical gel dosimeters Short title: Ultrasonic imaging of dose distribution Relevance: The proposed ultrasonic characterization of absorbed dose in polymer gel phantoms will enable rapid and accurate on-site calibration of modern radiation treatment equipment and help increase throughput and efficacy of future cancer treatment procedures. The ultimate goal is to provide accurate beam profile measurement in real time to interactively adjust multileaf collimator settings.