Raw data for: Thermoacoustic range verification during conventional dose rate delivery by a synchrocyclotron

Data (raw thermoacoustic data, as well as filtered pulses sorted by spot) for this paper are attached, and the paper abstract follows: Background: Minimization of range uncertainties is critical for precise and effective proton therapy. Thermoacoustic range verification is a promising non-invasive technique for pinpointing the Bragg peak location in proton therapy. Purpose: Verification of a prototype device for thermoacoustic range verification with minimal disruption to a clinical workflow for proton therapy delivered by a synchrocyclotron. Materials/Methods: 5-8 pC/pulse were delivered to a gelatin-ultrasound quality-assurance phantom by a Mevion Hyperscan S250i system in 200-300 pulses/spot. Spots were laterally separated by 25 mm; energy layers were separated in depth by 10 MeV. Thermoacoustic and nuclear emissions were captured by a wireless thermoacoustic range verifier, with radiation detector on board. Dose maps for individual beamlets were exported from RayStation 12A and used to compute initial values for finite element acoustic simulation, assuming Gaussian beam current with σ = 0.95 μs. The plan was re-delivered 9 times with varying thicknesses of solid-water equivalent phantom (Sun Nuclear) placed on the snout. Range shifts and total dose were recomputed and loaded into RayStation for comparison to the original plan. To assess applicability to clinical plans, analysis was performed by averaging N=16 pulses for which radiation detector signal exceeded 50% of its maximum. Finite element results were bandpass filtered, and time shifted to best match control measurements obtained without solid water on the snout. Results: Using only N=16 thermoacoustic pulses yielded best- and worst-case errors of and , averaged over all spots. Averaged over spots in a layer, best- and worst-case errors were 0.0 1.3 mm and -1.3 1.6 mm. Conclusions: A wireless range verification research device that can be setup in less than 10 minutes provided millimeter range accuracy in an ultrasound quality assurance phantom.本论文配套提供原始热声学数据，以及按照射斑点（spot）排序的滤波脉冲数据，下文为该论文摘要： 研究背景：射程不确定性的最小化是实现精准高效质子治疗的关键所在。热声学射程验证是一项极具应用前景的非侵入式技术，可精准确认质子治疗中的布拉格峰（Bragg peak）位置。 研究目的：旨在验证一款热声学射程验证原型设备，该设备可最大限度减少对同步回旋加速器（synchrocyclotron）递送的质子治疗临床工作流程的干扰。 材料与方法：采用Mevion Hyperscan S250i系统，以200~300个脉冲/斑点的剂量参数，向明胶基超声质量保证体模递送5~8皮库仑（pC）/脉冲的束流。各照射斑点横向间距为25 mm；能量层沿深度方向以10 MeV为间隔划分。搭载内置辐射探测器的无线热声学射程验证装置，采集热声学信号与核辐射信号。从RayStation 12A治疗计划系统中导出单个束斑的剂量分布，假设束流电流呈高斯分布（σ=0.95 μs），以此作为有限元声学仿真的初始参数。 该治疗计划被重复递送9次，同时在治疗头前端放置不同厚度的固体水等效体模（Sun Nuclear公司产品）。重新计算射程偏移与总剂量，并将结果导入RayStation，与原始治疗计划进行比对。 为评估该设备对临床治疗计划的适用性，选取辐射探测器信号超过其最大值50%的16个脉冲进行平均分析。对有限元仿真结果进行带通滤波，并实施时移处理，以最佳匹配未放置固体水的治疗头前端时获取的对照测量结果。 结果：仅使用16个热声学脉冲进行分析时，所有照射斑点的最优与最差工况误差分别为 与 ；对单个能量层内的照射斑点取平均后，最优与最差工况误差分别为0.0~1.3 mm与-1.3~1.6 mm。 结论：一款可在10分钟内完成搭建的无线射程验证研究设备，在超声质量保证体模中实现了毫米级的射程精度。