Anam Choirul, Kusuma Dewi Winda, Masdi Masdi, Haryanto Freddy, Fujibuchi Toshioh, Dougherty Geoff
PhD, Department of Physics, Faculty of Sciences and Mathematics, Diponegoro University, Jl. Prof. Soedarto SH, Semarang 50275, Central Java, Indonesia.
MSc, Department of Physics, Faculty of Sciences and Mathematics, Diponegoro University, Jl. Prof. Soedarto SH, Semarang 50275, Central Java, Indonesia.
J Biomed Phys Eng. 2021 Oct 1;11(5):563-572. doi: 10.31661/jbpe.v0i0.2104-1304. eCollection 2021 Oct.
Estimation of eye lens dose is important in head computed tomography (CT) examination since the eye lens is a sensitive organ to ionizing radiation.
The purpose of this study is to compare estimations of eye lens dose in head CT examinations using local size-specific dose estimate (SSDE) based on size-conversion factors of the American Association of Physicists in Medicine (AAPM) Report No. 293 with those based on size-conversion factors of the AAPM Report No. 220.
This experimental study is conducted on a group of patients who had undergone nasopharyngeal CT examination. Due to the longitudinal (-axis) dose fluctuation, the average global SSDE and average local SSDE (i.e. particular slices where the eyes are located) were investigated. All estimates were compared to the measurement results using thermo-luminescent dosimeters (TLDs). The estimated and measured doses were implemented for 14 patients undergoing nasopharyngeal CT examination.
It was found that the percentage differences of the volume CT dose index (CTDI), average global SSDE based on AAPM No. 220 (SSDE), average local SSDE based on AAPM No. 220 (SSDE), average global SSDE based on AAPM No. 293 (SSDE) and average local SSDE based on AAPM No. 293 (SSDE) against the measured TLD doses were 22.5, 21.7, 15.0, 9.3, and 2.1%, respectively. All comparisons between dose estimates and TLD measurements gave -values less than 0.001, except for SSDE (-value = 0.566).
SSDE based on AAPM Report No. 293 can be used to accurately estimate eye lens radiation doses by performing the calculations on a number of specific slices containing the eyes.
在头部计算机断层扫描（CT）检查中，晶状体剂量的估算很重要，因为晶状体是对电离辐射敏感的器官。
本研究的目的是比较在头部CT检查中，使用基于美国医学物理师协会（AAPM）第293号报告的尺寸转换因子的局部特定大小剂量估计（SSDE）与基于AAPM第220号报告的尺寸转换因子的SSDE对晶状体剂量的估算。
本实验研究针对一组接受过鼻咽部CT检查的患者进行。由于纵向（轴）剂量波动，研究了平均整体SSDE和平均局部SSDE（即眼睛所在的特定切片）。所有估算值均与使用热释光剂量计（TLD）的测量结果进行比较。对14名接受鼻咽部CT检查的患者进行了估算剂量和测量剂量的操作。
发现容积CT剂量指数（CTDI）、基于AAPM第220号报告的平均整体SSDE（SSDE）、基于AAPM第220号报告的平均局部SSDE（SSDE）、基于AAPM第293号报告的平均整体SSDE（SSDE）和基于AAPM第293号报告的平均局部SSDE（SSDE）与测量的TLD剂量的百分比差异分别为22.5%、21.7%、15.0%、9.3%和2.1%。除SSDE（P值 = 0.566）外，剂量估算值与TLD测量值之间的所有比较的P值均小于0.001。
基于AAPM第293号报告的SSDE可通过对包含眼睛的多个特定切片进行计算，准确估算晶状体辐射剂量。
