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arXiv 2109.05058physics.med-ph
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基于4D跟踪和通过飞行时间确定剩余能量的质子CT系统的可行性研究

Feasibility study of a proton CT system based on 4D-tracking and residual energy determination via time-of-flight

Felix Ulrich-Pur, Thomas Bergauer, Alexander Burker, Albert Hirtl, Christian Irmler, Stefanie Kaser, Florian Pitters, Simon Rit

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Preprint submitted to Physics in Medicine and Biology. IOP Publishing Ltd is not responsible for any errors or omissions in this version of the manuscript or any version derived from it
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摘要：

对于离子束治疗中的剂量计算，准确确定治疗体积内的相对阻止本领（RSP）分布至关重要。目前，RSP值是从用X射线计算机断层成像（CT）测量的Hounsfield单位（HU）外推的，由于转换误差，这导致RSP不准确。提高治疗计划精度的合适方法是质子计算机断层成像（pCT）。典型的pCT系统由跟踪系统和单独的残余能量（或范围）检测器组成，以直接测量RSP分布。本文介绍了一种基于单探测器技术的新型pCT系统，即低增益雪崩探测器（LGAD）。LGAD是快速的4D跟踪探测器，可用于同时测量粒子的位置和时间，具有精确的时间和空间分辨率。与标准pCT系统相比，剩余能量通过不同4D跟踪站之间的飞行时间（TOF）测量来确定。利用蒙特卡罗模拟对基于4D跟踪探测器的质子计算机断层成像系统的设计参数进行了研究和优化。在CTP 404体模的插入物内测量RSP准确度和RSP分辨率，以估计pCT系统的性能。在为TOF量热计引入专用校准程序后，可以实现RSP精度<0.6%。此外，与最强的RSP分辨率的影响的设计参数被确定，并提出了一种策略，以提高RSP分辨率。

英文摘要：

For dose calculations in ion beam therapy, it is vital to accurately determine the relative stopping power (RSP) distribution within the treated volume. Currently, RSP values are extrapolated from Hounsfield units (HU), measured with x-ray computed tomography (CT), which entails RSP inaccuracies due to conversion errors. A suitable method to improve the treatment plan accuracy is proton computed tomography (pCT). A typical pCT system consists of a tracking system and a separate residual energy (or range) detector to measure the RSP distribution directly. This paper introduces a novel pCT system based on a single detector technology, namely low gain avalanche detectors (LGADs). LGADs are fast 4D-tracking detectors, which can be used to simultaneously measure the particle position and time with precise timing and spatial resolution. In contrast to standard pCT systems, the residual energy is determined via a time-of-flight (TOF) measurement between different 4D-tracking stations. The design parameters for a realistic proton computed tomography system based on 4D-tracking detectors were studied and optimized using Monte Carlo simulations. The RSP accuracy and RSP resolution were measured inside the inserts of the CTP404 phantom to estimate the performance of the pCT system. After introducing a dedicated calibration procedure for the TOF calorimeter, RSP accuracies < 0.6 % could be achieved. Furthermore, the design parameters with the strongest impact on the RSP resolution were identified and a strategy to improve RSP resolution is proposed.

机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。

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