标题： 一种快速解析（1000 Hz）塑料闪烁体在超高速率电子剂量测量中的综合表征与验证 显示英文标题

标题： Comprehensive characterization and validation of a fast-resolving (1000 Hz) plastic scintillator for ultra-high dose rate electron dosimetry

摘要： 背景：与常规剂量率（CONV）相比，超高剂量率照射（>40 Gy/s，UHDR）的正常组织保护效应引起了对FLASH放疗（RT）的重大研究兴趣。 需要准确、与剂量率无关、响应快速的剂量计，能够解析UHDR束的时空特性，以促进FLASH研究并支持其临床转化。 组织等效闪烁体具有毫米级空间分辨率和毫秒级时间分辨率，具备这些所需特性，并在UHDR剂量测定中显示出强大潜力。 目的：我们研究了HYPERSCINT RP-FLASH闪烁体系统在最高1000 Hz采样频率（fs）下的性能，用于UHDR电子束剂量测定。 方法：使用基于LINAC的FLASH平台，将闪烁体暴露于CONV和UHDR电子照射。 通过四组分校准确定其光谱特性，随后使用18 MeV CONV电子束进行信号-剂量校准。 相对于电离室和EBT-XD胶片测量，量化了在1 Hz和1000 Hz fs下对CONV和UHDR照射的剂量线性和剂量准确性。 研究了闪烁体系统的响应作为束能（6和18 MeV）、照射野大小（2x2至25x25 cm2）、每脉冲剂量（DPP，0.8至2.3 Gy/脉冲）和脉冲重复频率（PRF，30至180 Hz）的函数。 相对于累积剂量量化相对信号灵敏度，以考虑闪烁体的辐射退化。 使用1000 Hz fs的闪烁体，在180 Hz PRF下对10个脉冲的脉冲序列进行了18 MeV UHDR的脉冲分辨剂量测量，并通过PMT-光纤散射辐射探测器进行了验证。 显示英文摘要

摘要： Background: The normal tissue sparing effect of ultra-high dose rate irradiation (>40 Gy/s, UHDR), as compared to conventional dose rate (CONV), has attracted significant research interest for FLASH radiotherapy (RT). Accurate, dose rate independent, fast-responding dosimeters capable of resolving the spatiotemporal characteristics of UHDR beams are urgently needed to facilitate FLASH research and support its clinical translation. Tissue-equivalent scintillators, with millimeter-level spatial resolution and millisecond-level temporal resolution, possess these required characteristics and show strong potential for use in UHDR dosimetry. Purpose: We investigated the performance of the HYPERSCINT RP-FLASH scintillator system at up to 1000 Hz sampling frequency (fs) for UHDR electron beam dosimetry. Methods: The scintillator was exposed to CONV and UHDR electron irradiation using a LINAC-based FLASH platform. Its spectral characteristics were delineated with a four-component calibration, followed by a signal-to-dose calibration using 18 MeV CONV electron beam. The dose linearity and dosimetric accuracy in response to CONV and UHDR irradiation at 1 and 1000 Hz fs were quantified against ion chamber and EBT-XD film measurements. The response of the scintillator system was investigated as a function of beam energy (6 and 18 MeV), field size (2x2 to 25x25 cm2), dose per pulse (DPP, 0.8 to 2.3 Gy/pulse), and pulse repetition frequency (PRF, 30 to 180 Hz). Relative signal sensitivity was quantified against accumulated dose to account for the scintillator's radiation degradation. Pulse-resolved dose measurements at 18 MeV UHDR, obtained using the scintillator with 1000 Hz fs for a train of 10 pulses at 180 Hz PRF, were validated with a PMT-fiber optic scattered radiation detector.