We report on the design, fabrication, and first tests of a tomographic scanner developed for proton computed tomography (pCT) of head-sized objects. After extensive preclinical testing, pCT is intended to be employed in support of proton therapy treatment planning and pre-treatment verification in patients undergoing particle-beam therapy. The scanner consists of two silicon-strip telescopes that track individual protons before and after the phantom, and a novel multistage scintillation detector that measures a combination of the residual energy and range of the proton, from which we derive the water equivalent path length (WEPL) of the protons in the scanned object. The set of WEPL values and the associated paths of protons passing through the object over a 360 ° angular scan are processed by an iterative, parallelizable reconstruction algorithm that runs on modern GP-GPU hardware. In order to assess the performance of the scanner, we have performed tests with 200 MeV protons from the synchrotron of the Loma Linda University Medical Center and the IBA cyclotron of the Northwestern Medicine Chicago Proton Center. Our first objective was calibration of the instrument, including tracker channel maps and alignment as well as the WEPL calibration. Then we performed the first CT scans on a series of phantoms. The very high sustained rate of data acquisition, exceeding one million protons per second, allowed a full 360 ° scan to be completed in less than 10 minutes, and reconstruction of a CATPHAN 404 phantom verified accurate reconstruction of the proton relative stopping power in a variety of materials.

中文翻译：

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用于质子 CT 的快速实验扫描仪：技术性能和体模扫描的初次体验


我们报告了为头部大小物体的质子计算机断层扫描 (PCT) 开发的断层扫描仪的设计、制造和首次测试。经过广泛的临床前测试，pCT 旨在支持接受粒子束治疗的患者的质子治疗计划和治疗前验证。该扫描仪由两个硅带望远镜组成，用于跟踪模型前后的单个质子，以及一个新颖的多级闪烁探测器，用于测量质子的剩余能量和射程的组合，从中我们可以得出水等效路径长度（WEPL ）被扫描物体中的质子。 WEPL 值集以及通过 360° 角度扫描穿过物体的质子的相关路径由在现代 GP-GPU 硬件上运行的迭代、可并行重建算法进行处理。为了评估扫描仪的性能，我们使用来自洛马琳达大学医学中心的同步加速器和西北医学芝加哥质子中心的 IBA 回旋加速器的 200 MeV 质子进行了测试。我们的第一个目标是校准仪器，包括跟踪器通道图和对准以及 WEPL 校准。然后我们对一系列模型进行了第一次 CT 扫描。数据采集​​的持续速率非常高，每秒超过一百万个质子，可以在不到 10 分钟内完成完整的 360° 扫描，并且 CATPHAN 404 模型的重建验证了各种情况下质子相对阻止本领的准确重建。的材料。