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

描述(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简称：剂量分布的超声成像项目概述露娜与Carilion Health System合作，提出开发和测试一种高分辨率超声技术，用于非侵入性地表征临床凝胶剂量计中的吸收剂量分布。辐射引起的凝胶性能退化是获取空间剂量分布的有效方法，可以通过后处理揭示空间剂量分布。与传统的剂量测量技术相比，存储3D剂量信息的能力是一个明显的优势，例如水量热法、电离室和基于胶片的方法。然而，目前部署的使用磁共振成像和光学层析成像的后处理方法价格昂贵，并且需要长时间的非现场处理。该方法基于精确的超声信号相位测量技术，可以检测材料性能变化引起的声速变化，精度优于20ppm。它将为存储在凝胶中的剂量信息提供低成本、近实时的现场解释，并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超声扫描系统，制备具有剂量分布记忆的凝胶样品，并根据临床环境中受到电离辐射的几个定制凝胶样品的扇束层析几何形状采集超声透射式信号。我们将重建吸收剂量的空间分布，并将它们与传统扫描电离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，以及它正确处理折射和边界过渡伪影的能力。在第二阶段，我们将开发一种基于环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。基于阵列的原型将允许使用最少的设备快速成像标准化凝胶样本中的剂量分布-可能是一个带有USB连接到笔记本电脑的单一盒子。这项新技术将满足对现代放射治疗设备的快速和准确的现场校准的需求，从而提高未来癌症治疗程序的产量和效率。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：剂量分布相关性的超声成像：提出的聚合物凝胶模体中吸收剂量的超声表征将使现代放射治疗设备能够快速和准确地进行现场校准，并有助于提高未来癌症治疗程序的吞吐量和有效性。最终目标是提供实时精确的光束轮廓测量，以交互方式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.