Hansson U, Johansson K A
Radiation Physics Department, University of Gothenburg, Sahlgren Hospital, Sweden.
Radiother Oncol. 1991 Mar;20(3):191-6. doi: 10.1016/0167-8140(91)90096-y.
A mailable TL-dosimetry (LiF) system has been designed and tested for the EORTC Radiotherapy Group for periodic monitoring of radiation therapy machines between and prior to on-site visits. Three TL-dosimeters were enclosed in a capsule which was placed in a holder and irradiated in photon beams in a water phantom. The institutes were instructed to irradiate the capsule to an absorbed dose of 2 Gy. After the irradiation, all capsules with dosimeter, the holder and completed data sheets were returned to Gothenburg for evaluation. The heating procedure used for reading the dosimeters was optimised regarding fading and reproducibility (less than 0.5%, 1. S.D.). The fading of the TL-signal was eliminated by adding an external annealing to the heating procedure. Both supralinearity and energy dependence were tested and routinely corrected for. The dosimeters were individually calibrated. During 1987, 1988 and the first part of 1989, dosimeters were mailed to 22 institutes, participating in clinical trials organised by the Radiotherapy Group. Of the 178 beams measured, 89% were within acceptable levels of variation for the absorbed dose states (less than or equal to 4%). The photon results gave a mean of 1.012 and a standard deviation of 0.025.
已为欧洲癌症研究与治疗组织（EORTC）放射治疗组设计并测试了一种可邮寄的热释光剂量测定（LiF）系统，用于在现场访问之间及之前定期监测放射治疗机器。三个热释光剂量计封装在一个胶囊中，该胶囊放置在一个支架上，并在水模体的光子束中进行照射。各机构接到指示，将胶囊照射至2 Gy的吸收剂量。照射后，所有装有剂量计的胶囊、支架和填好的数据表都返回哥德堡进行评估。用于读取剂量计的加热程序在褪色和再现性方面（小于0.5%，1个标准差）进行了优化。通过在加热程序中增加外部退火消除了热释光信号的褪色。对超线性和能量依赖性都进行了测试并进行常规校正。剂量计进行了单独校准。在1987年、1988年和1989年上半年，剂量计被邮寄到22个机构，这些机构参与了放射治疗组组织的临床试验。在测量的178束射线中，89%的射线在吸收剂量状态的可接受变化范围内（小于或等于4%）。光子测量结果的平均值为1.012，标准差为0.025。
