Thayer School of Engineering, Dartmouth College, Hanover, NH, USA.
DoseOptics LLC, Lebanon, NH, USA.
J Appl Clin Med Phys. 2020 Jun;21(6):158-162. doi: 10.1002/acm2.12880. Epub 2020 Apr 19.
The novel scintillator-based system described in this study is capable of accurately and remotely measuring surface dose during Total Skin Electron Therapy (TSET); this dosimeter does not require post-exposure processing or annealing and has been shown to be re-usable, resistant to radiation damage, have minimal impact on surface dose, and reduce chances of operator error compared to existing technologies e.g. optically stimulated luminescence detector (OSLD). The purpose of this study was to quantitatively analyze the workflow required to measure surface dose using this new scintillator dosimeter and compare it to that of standard OSLDs.
Disc-shaped scintillators were attached to a flat-faced phantom and a patient undergoing TSET. Light emission from these plastic discs was captured using a time-gated, intensified, camera during irradiation and converted to dose using an external calibration factor. Time required to complete each step (daily QA, dosimeter preparation, attachment, removal, registration, and readout) of the scintillator and OSLD surface dosimetry workflows was tracked.
In phantoms, scintillators and OSLDs surface doses agreed within 3% for all data points. During patient imaging it was found that surface dose measured by OSLD and scintillator agreed within 5% and 3% for 35/35 and 32/35 dosimetry sites, respectively. The end-to-end time required to measure surface dose during phantom experiments for a single dosimeter was 78 and 202 sec for scintillator and OSL dosimeters, respectively. During patient treatment, surface dose was assessed at 7 different body locations by scintillator and OSL dosimeters in 386 and 754 sec, respectively.
Scintillators have been shown to report dose nearly twice as fast as OSLDs with substantially less manual work and reduced chances of human error. Scintillator dose measurements are automatically saved to an electronic patient file and images contain a permanent record of the dose delivered during treatment.
本研究中描述的新型闪烁体系统能够在全身电子治疗（TSET）期间准确、远程测量表面剂量；该剂量仪无需曝光后处理或退火，并且已经证明是可重复使用的，对辐射损伤具有抵抗力，对表面剂量的影响最小，并且与现有技术（例如光激励发光探测器（OSLD））相比，减少了操作人员出错的机会。本研究的目的是定量分析使用这种新型闪烁体剂量仪测量表面剂量所需的工作流程，并将其与标准 OSLD 进行比较。
将圆盘形闪烁体附着在平面体模和接受 TSET 的患者上。在照射过程中，使用时间门控、增强型相机捕获来自这些塑料圆盘的光发射，并使用外部校准因子将其转换为剂量。记录闪烁体和 OSLD 表面剂量学工作流程中完成每个步骤（日常 QA、剂量仪准备、附件、移除、注册和读取）所需的时间。
在体模中，闪烁体和 OSLD 的表面剂量在所有数据点的误差均在 3%以内。在患者成像过程中，发现 OSLD 和闪烁体测量的表面剂量在 35/35 和 32/35 剂量点分别为 5%和 3%以内。单个剂量仪在体模实验中测量表面剂量所需的端到端时间分别为闪烁体和 OSL 剂量仪的 78 和 202 秒。在患者治疗期间，闪烁体和 OSL 剂量仪分别在 7 个不同的身体部位在 386 和 754 秒内评估了表面剂量。
与 OSLD 相比，闪烁体的剂量报告速度快了近一倍，手动工作量大大减少，人为错误的机会减少。闪烁体剂量测量自动保存到电子患者文件中，图像包含治疗期间给予的剂量的永久记录。
