Feasibility study of a plastic scintillating plate-based treatment beam fluence monitoring system for use in pencil beam scanning proton therapy.
Feasibility study of a plastic scintillating plate-based treatment beam fluence monitoring system for use in pencil beam scanning proton therapy.
复制标题
用于笔形束扫描质子治疗的基于塑料闪烁板的治疗束注量监测系统的可行性研究。
DOI：
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发表时间：
2019
期刊：
影响因子：
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通讯作者：
M. Yoon
中科院分区：
文献类型：
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作者：
Seonghoon Jeong;K. Chung;Sung Hwan Ahn;Boram Lee;Jaehyeon Seo;M. Yoon
目的
描述一种用于铅笔束扫描质子治疗监测入射质子注量的塑料闪烁板式龙门式剂量测量系统，并评价该系统的剂量学特性及其临床应用的可行性。
方法
该剂量测量系统由一个塑料闪烁板和一个cmos相机组成，安装在一个专用的扫描喷嘴上，记录了质子辐照过程中的闪烁。根据累积的记录帧计算剂量分布。测量了用于治疗质子束的机架式剂量测量系统的剂量学特性(能量依赖性、剂量线性、剂量率依赖性和重复性)，并通过确定我所选定的质量保证项目来评估该系统在临床应用的可行性。
结果
在70 MeV下，闪烁板使质子束射程缩短了相当于板的水当量厚度，并使单质子点的空间分布展宽了11%。开发的系统独立于束流能量(<；1.3%)运行，并显示出剂量线性，也独立于剂量率运行。通过将测量的质量保证剂量分布与治疗计划系统的剂量分布进行比较，评估该系统用于临床的可行性。以3%/3 mm为标准的伽马通过率为97.58%。
结论
这项研究评估了用于扫描质子束的基于塑料闪烁平板的剂量测量系统的剂量学特性。考虑到剂量测量系统对治疗射束的干扰的能力使得能够以高分辨率并以经济高效的方式独立于治疗系统对铅笔束扫描质子治疗的入射射束注量进行离线监测。
PURPOSE
To describe a plastic scintillating plate-based gantry-attachable dosimetry system for pencil beam scanning proton therapy to monitor entrance proton beam fluence, and to evaluate the dosimetric characteristics of this system and its feasibility for clinical use.
METHODS
The dosimetry system, consisting of a plastic scintillating plate and a CMOS camera, was attached to a dedicated scanning nozzle and scintillation during proton beam irradiation was recorded. Dose distribution was calculated from the accumulated recorded frames. The dosimetric characteristics (energy dependency, dose linearity, dose-rate dependency, and reproducibility) of the gantry-attachable dosimetry system for use with therapeutic proton beams were measured, and the feasibility of this system during clinical use was evaluated by determining selected quality assurance items at our institution.
RESULTS
The scintillating plate shortened the range of the proton beam by the water-equivalent thickness of the plate and broadened the spatial profile of the single proton spot by 11% at 70 MeV. The developed system functioned independently of the beam energy (< 1.3%) and showed dose linearity, and also functioned independently of the dose rate. The feasibility of the system for clinical use was evaluated by comparing the measured quality assurance dose distribution to that of the treatment planning system. The gamma passing rate with a criterion of 3%/3 mm was 97.58%.
CONCLUSIONS
This study evaluated the dosimetric characteristics of a plastic scintillating plate-based dosimetry system for use with scanning proton beams. The ability to account for the interference of the dosimetry system on the therapeutic beam enabled offline monitoring of the entrance beam fluence of the pencil beam scanning proton therapy independent of the treatment system with high resolution and in a cost effective manner.