Borrás C, Liss M M, Thomason C, Hidalgo-Salvatierra O, White C P, Barton J E
Western Center for Radiological Physics, West Coast Cancer Foundation, San Francisco, CA 94133.
Health Phys. 1987 Dec;53(6):631-7. doi: 10.1097/00004032-198712000-00006.
As part of a U.S. multi-regional pilot study conducted by the six Centers for Radiological Physics, 12-mm-diameter by 0.4-mm-thick CaSO4:Dy Teflon-embedded discs were evaluated and used to measure patient entrance exposure on 60 "average" patients at 12 clinical centers. The discs were found to have adequate sensitivity, reproducibility and linearity up to 69.7 microC kg-1 (270 mR). The minimum measurable exposure was estimated as 0.4 microC kg-1 (1.5 mR). All responses were corrected for energy dependence, which varied +/- 20% from 1.7 to 6.5 mm Al half-value layer. Patient entrance exposure values ranged from 1.3 to 28 microC kg-1 (5 to 110 mR), with a median value of 5.2 microC kg-1 (20 mR). This value agreed with exposure measurements made on the chest radiography equipment using an ionization chamber and a phantom which simulated an "average" patient, and with published Nationwide Evaluation of X-Ray Trends (NEXT) data for the same period.
作为美国六个放射物理中心开展的一项多区域试点研究的一部分，对直径12毫米、厚度0.4毫米、嵌入聚四氟乙烯的硫酸钙镝（CaSO4:Dy）圆盘进行了评估，并用于测量12个临床中心60名“普通”患者的体表入射剂量。结果发现，这些圆盘在高达69.7微库仑/千克（270毫伦琴）的剂量范围内具有足够的灵敏度、再现性和线性度。估计的最小可测剂量为0.4微库仑/千克（1.5毫伦琴）。所有响应均针对能量依赖性进行了校正，能量依赖性在1.7至6.5毫米铝半价层范围内变化±20%。患者体表入射剂量值范围为1.3至28微库仑/千克（5至110毫伦琴），中位数为5.2微库仑/千克（20毫伦琴）。该值与使用电离室和模拟“普通”患者的体模在胸部X光摄影设备上进行的剂量测量结果一致，也与同期公布的全国X射线趋势评估（NEXT）数据一致。
