Choi Tae Won, Chung Jin Wook, Cha Bo Kyung, Choi Kwang Nam, Park Sohyeon, Son Jeong Woo, Choi Chang Heon
Department of Radiology, Seoul National University Hospital, Seoul, Republic of Korea.
Electro-Medical Device Research Center, Korea Electrotechnology Research Institute, Ansan, Republic of Korea.
J Radiol Prot. 2020 Nov 11;40(4). doi: 10.1088/1361-6498/abbf3a.
This study investigated the feasibility of dosimetric measurements using Al2O3:C optically stimulated luminescence (OSL) dosimeters during fluoroscopy-guided procedures. The linearity and energy dependence of Al2O3:C OSL dosimeters were evaluated, and the air kerma rate at the operator's position was measured. The response of Al2O3:C OSL dosimeters to short, repetitive irradiations was compared to that of long uninterrupted irradiation. The change in response of the Al2O3:C OSL dosimeter under automatic exposure rate control (AERC) was evaluated with the use of various thicknesses of polymethyl-methacrylate (PMMA) plates (15-30 cm). The Al2O3:C OSL dosimeters could detect 5Gy and showed good linearity in doses of ≥10Gy (R: 0.997-0.999,< 0.001). The relative response of the Al2O3:C OSL dosimeter normalised to that of 36.8 keV was 0.828-1.101 at the energies investigated (30.6-46.0 keV). The air kerma rate at the operator's position was estimated to be 2.61-7.17Gy mindepending on the heights representing different body parts. Repetitive short irradiations had no significant impact on the relative response of the Al2O3:C OSL dosimeters (> 0.05). Despite a high energy dependence on the low energy beam used in fluoroscopy, the change in relative response of the Al2O3:C OSL dosimeter under AERC was within 5.7% depending on the thickness of the PMMA plates. Dosimetric measurement using Al2O3:C OSL dosimeters for patients and operators is feasible. However, one should be cautious about high standard deviations when measuring small doses of ≤20Gy using Al2O3:C OSL dosimeters. It is essential to perform intensive bleaching before measuring very small doses to minimise pre-irradiation counts.
本研究调查了在荧光透视引导手术过程中使用Al2O3:C光激励发光（OSL）剂量计进行剂量测量的可行性。评估了Al2O3:C OSL剂量计的线性和能量依赖性，并测量了操作者位置的空气比释动能率。将Al2O3:C OSL剂量计对短时间重复照射的响应与长时间连续照射的响应进行了比较。使用各种厚度的聚甲基丙烯酸甲酯（PMMA）板（15 - 30 cm）评估了Al2O3:C OSL剂量计在自动曝光率控制（AERC）下的响应变化。Al2O3:C OSL剂量计可检测到5Gy，并且在≥10Gy剂量下显示出良好的线性（R：0.997 - 0.999，<0.001）。在所研究的能量（30.6 - 46.0 keV）下，归一化为36.8 keV的Al2O3:C OSL剂量计的相对响应为0.828 - 1.101。根据代表不同身体部位的高度，操作者位置的空气比释动能率估计为2.61 - 7.17Gy/min。重复短时间照射对Al2O3:C OSL剂量计的相对响应没有显著影响（>0.05）。尽管对荧光透视中使用的低能束具有较高的能量依赖性，但根据PMMA板的厚度，Al2O3:C OSL剂量计在AERC下的相对响应变化在5.7%以内。使用Al2O3:C OSL剂量计对患者和操作者进行剂量测量是可行的。然而，使用Al2O3:C OSL剂量计测量≤20Gy的小剂量时，应注意高标准偏差。在测量非常小的剂量之前进行强化漂白以最小化预照射计数是至关重要的。
