Characterization of optically stimulated luminescent dosimeters, OSLDs, for clinical dosimetric measurements
Characterization of optically stimulated luminescent dosimeters, OSLDs, for clinical dosimetric measurements
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DOI：
10.1118/1.2804555
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发表时间：
2007-12-01
期刊：
影响因子：
3.8
通讯作者：
Jursinic, Paul A.
中科院分区：
文献类型：
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作者：
Jursinic, Paul A.
光激励发光剂量计（OSLD）是注入了掺杂有碳的氧化铝（Al 2 O3：C）的塑料盘。这些磁盘装在一个不透光的塑料保持器中。当暴露于电离辐射时，Al 2 O3：C晶体存储能量，当OSLD用刺激光（540 nm）照射时，该能量作为发光（420 nm）释放。发光强度取决于OSLD吸收的剂量和刺激光的强度。在这项工作中使用的OSLD是InLight/OSL Dot剂量计，其用MicroStar读取器（Landauer，Inc.，格伦伍德，IL）。以下是测定的OSLD的剂量测定特性：在单次照射后，重复读数导致信号每次阅读降低0.05%;通过用150 W钨-卤素灯照射它们超过45 s，信号可以被释放大于98%;在照射后，存在以0.8 min半衰期衰减的瞬态信号;瞬态信号衰减后，信号稳定数日，单个OSLD重复辐照和读数的信号变异系数为0.6%，一批OSLD的剂量灵敏度变异系数为0.9%，在1-300 cGy的测试范围内，响应与吸收剂量呈线性关系;在300 cGy以上，出现小的超线性行为，在388倍的范围内没有剂量/脉冲依赖性，对于6和15 MV X射线和6-20 MeV电子，没有辐射能量或模式的依赖性，对于Ir-192 γ射线，OSLD的灵敏度高6%;剂量敏感性在累积剂量达20戈伊时不变，此后每增加10戈伊，剂量敏感性下降4%，剂量敏感性与入射角无关;在不透光的情况下，OSLD具有0.04 g/cm（2）的固有累积; OSLD的剂量灵敏度不依赖于在10-40 ℃范围内照射时的温度。OSLD在体内剂量测定的临床应用是可行的。(C)2007年美国医学物理学家协会。
Optically stimulated luminescent dosimeters, OSLDs, are plastic disks infused with aluminum oxide doped with carbon (Al2O3:C). These disks are encased in a light-tight plastic holder. Crystals of Al2O3:C when exposed to ionizing radiation store energy that is released as luminescence (420 nm) when the OSLD is illuminated with stimulation light (540 nm). The intensity of the luminescence depends on the dose absorbed by the OSLD and the intensity of the stimulation light. OSLDs used in this work were InLight/OSL Dot dosimeters, which were read with a MicroStar reader (Landauer, Inc., Glenwood, IL). The following are dosimetric properties of the OSLD that were determined: After a single irradiation, repeated readings cause the signal to decrease by 0.05% per reading; the signal could be discharged by greater than 98% by illuminating them for more than 45 s with a 150 W tungsten-halogen light; after irradiation there was a transient signal that decayed with a 0.8 min halftime; after the transient signal decay the signal was stable for days; repeated irradiations and readings of an individual OSLD gave a signal with a coefficient of variation of 0.6%; the dose sensitivity of OSLDs from a batch of detectors has a coefficient of variation of 0.9%, response was linear with absorbed dose over a test range of 1-300 cGy; above 300 cGy a small supra-linear behavior occurs; there was no dose-per-pulse dependence over a 388-fold range; there was no dependence on radiation energy or mode for 6 and 15 MV x rays and 6-20 MeV electrons; for Ir-192 gamma rays OSLD had 6% higher sensitivity; the dose sensitivity was unchanged up to an accumulated dose of 20 Gy and thereafter decreased by 4% per 10 Gy of additional accumulated dose; dose sensitivity was not dependent on the angle of incidence of radiation; the OSLD in its light-tight case has an intrinsic buildup of 0.04 g/cm(2); dose sensitivity of the OSLD was not dependent on temperature at the time of irradiation in the range of 10-40 degrees C. The clinical use of OSLDs for in vivo dosimetric measurements is shown to be feasible. (C) 2007 American Association of Physicists in Medicine.