论文标题
UHDR Flash放射疗法的二极管剂量计的表征
Characterization of a Diode Dosimeter for UHDR FLASH Radiotherapy
论文作者
论文摘要
目的：具有新设计的电表的二极管边缘检测器已在UHDR电子束中使用，并显示出对UHDR Flash放射疗法剂量测定法的适当性。 方法：对边缘检测器的每个脉冲依赖性剂量线性，平均剂量率和剂量进行了量化，并将其与包括W1闪烁体检测器，放射性膜和用10 MEV UHDR束受照射的电离室在内的剂量计进行了比较。通过内部开发的基于闪烁的反馈机制，线性加速器的重复速率和源到表面距离来控制每个脉冲的剂量，剂量率和剂量。将分别在单个脉冲分辨率下的深度剂量曲线和时间谱分别与膜和闪烁测量进行了比较。辐射诱导的响应灵敏度变化通过〜5 kgy的辐射来量化。 结果：边缘检测器与测得的范围内的膜测量值一致，剂量（最高70 Gy），剂量速率（接近200 Gy/s）和每脉冲的剂量平均为2％，5％和1％。该检测器还同意W1闪烁检测器的平均剂量（最高0.78 Gy/脉冲）的2％以内。边缘检测器信号与测量的离子室（IC）剂量成正比，Bremsstrahung尾巴的平均剂量率分别在0.4％和0.2％以内。边缘检测器测量的深度剂量与膜一致的百分比在3％以内，并且每脉冲输出量与W1闪烁体一致，至-6％至 +5％以内。 结论：边缘检测器表现出剂量线性，平均剂量率独立性和UHDR电子束的每个脉冲独立性的剂量。它可以在次毫秒的分辨率下在空间和时间上量化光束。
Purpose: A diode EDGE Detector with a newly designed electrometer has been characterized for use in an UHDR electron beam and demonstrated appropriateness for UHDR FLASH radiotherapy dosimetry. Methods: Dose linearity, mean dose rate, and dose per pulse dependencies of the EDGE Detector were quantified and compared with dosimeters including a W1 scintillator detector, radiochromic film, and ionization chamber that were irradiated with a 10 MeV UHDR beam. The dose, dose rate and dose per pulse were controlled via an in-house developed scintillation-based feedback mechanism, repetition rate of the linear accelerator, and source-to-surface distance, respectively. Depth-dose profiles and temporal profiles at individual pulse resolution were compared to the film and scintillation measurements, respectively. The radiation-induced change in response sensitivity was quantified via irradiation of ~5kGy. Results: The EDGE Detector agreed with film measurements in the measured range with varying dose (up to 70 Gy), dose rate (nearly 200 Gy/s), and dose per pulse (up to 0.63 Gy/pulse) on average to within 2%, 5%, and 1%, respectively. The detector also agreed with W1 scintillation detector on average to within 2% for dose per pulse (up to 0.78 Gy/pulse). The EDGE Detector signal was proportional to ion chamber (IC) measured dose, and mean dose rate in the bremsstrahlung tail to within 0.4% and 0.2% respectively. The EDGE Detector measured percent depth dose agreed with film to within 3% and per pulse output agreed with W1 scintillator to within -6% to +5%. Conclusions: The EDGE Detector demonstrated dose linearity, mean dose rate independence, and dose per pulse independence for UHDR electron beams. It can quantify the beam spatially, and temporally at sub millisecond resolution.
