Non-contact scintillator imaging dosimetry for total body irradiation in radiotherapy.
Non-contact scintillator imaging dosimetry for total body irradiation in radiotherapy.
复制标题
放射治疗中全身照射的非接触式闪烁体成像剂量测定。
DOI：
10.1088/1361-6560/ad1a23
复制
发表时间：
2024
影响因子：
3.5
通讯作者：
Pogue,BrianW
中科院分区：
文献类型：
--
作者：
Niver,AlexanderP;Hammer,CliffordG;Culberson,WesleyS;Jacqmin,Dustin;Pogue,BrianW
目的探讨非接触式闪烁体成像剂量法在全身照射（TBI）中追踪递送的潜在应用价值。方法研究测量了放置在组织上的闪烁体辐射暴露引起的时间门控光信号。目的是评估TBI常见情况下的疗效，如常用的大源表面距离（SSD），降低剂量率，包括有机玻璃扰流片，入射角和周围患者支持结构的影响。剂量验证工作在模拟人体组织光学特性和人体几何形状的幻影上进行。在这项工作中，开发了直径1.5 cm的闪烁盘，并在各种条件下将其贴在幻影上。采用与直线脉冲同步的时间门控摄像机进行成像。在后处理中对闪烁强度进行了量化，并用热致发光剂量计（TLD）同时测量值进行了验证。将每个区域的平均闪烁值与TLD测量值进行比较以产生剂量响应曲线，并量化扰流器和患者床的散射效应。主要结果在TBI条件下，闪烁体测定的剂量与TLD测定的剂量吻合度在2.7%以内，反复吻合的标准差方差在1.0%以内。闪烁体信号与TLD剂量呈线性拟合，在多个身体部位的r2 = 0.996。病床上的分散导致剂量最大增加19%。意义本研究提示非接触式闪烁体成像剂量法可以在规定的长SSD和低剂量率下实时验证TBI患者的剂量。研究还表明，病人运输担架可以通过增加散射来显著影响表面剂量。
ObjectiveThe goal of this work was to assess the potential use of non-contact scintillator imaging dosimetry for tracking delivery in total body irradiation (TBI).ApproachStudies were conducted to measure the time-gated light signals caused by radiation exposure to scintillators that were placed on tissue. The purpose was to assess efficacy in conditions common for TBI, such as the large source to surface distance (SSD) commonly used, the reduced dose rate, the inclusion of a plexiglass spoiler, angle of incidence and effects of peripheral patient support structures. Dose validation work was performed on phantoms that mimicked human tissue optical properties and body geometry. For this work, 1.5 cm diameter scintillating disks were developed and affixed to phantoms under various conditions. A time-gated camera synchronized to the linac pulses was used for imaging. Scintillation intensity was quantified in post processing and the values verified with simultaneous thermolumiescent dosimeter (TLD) measurements. Mean scintillation values in each region were compared to TLD measurements to produce dose response curves, and scatter effects from the spoiler and patient bed were quantified.Main resultsThe dose determined by scintillators placed in TBI conditions agreed with TLD dose determinations to within 2.7%, and did so repeatedly within 1.0% standard deviation variance. A linear fit between scintillator signal and TLD dose was achieved with an R 2= 0.996 across several body sites. Scatter from the patient bed resulted in a maximum increase of 19% in dose.SignificanceThis work suggests that non-contact scintillator imaging dosimetry could be used to verify dose in real time to patients undergoing TBI at the prescribed long SSD and low dose rate. It also has shown that patient transport stretchers can significantly influence surface dose by increasing scatter.