Dose rate constant of a cesium-131 interstitial brachytherapy seed measured by thermoluminescent dosimetry and gamma-ray spectrometry.
Dose rate constant of a cesium-131 interstitial brachytherapy seed measured by thermoluminescent dosimetry and gamma-ray spectrometry.
复制标题
通过热释光剂量测定法和伽玛射线光谱测定法测量铯 131 间质近距离放射治疗种子的剂量率常数。
DOI：
10.1118/1.2098127
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发表时间：
2005
期刊：
影响因子：
3.8
通讯作者：
Nath,R
中科院分区：
文献类型：
--
作者：
Chen,Z;Bongiorni,P;Nath,R
这项工作的目的是对新引入的CS-1型粒子的剂量率常数进行独立测定。从种子生产商处共获得8粒种子。由制造商测量每个种子的空气比释动能强度，其校准可追溯到美国国家标准与技术研究所为种子建立的空气比释动能强度标准（不确定度）。通过两种独立的方法测量每个种子的剂量率常数：一种是基于使用伽马射线光谱法的种子发射的实际光子能量谱，另一种是基于Solid Water™体模中热释光剂量计（Thermoluminescent dosemeter，简称PDT）测量的剂量率。通过伽马射线能谱技术和放射性核素剂量测定法测定的水中剂量率常数分别为和，显示出彼此非常一致。然而，这些值比先前报道的值[Med.Phys.31，1529-1538（2004）]大约15%。尽管在晶种的能谱中测量了16.6和18.7 keV的低能荧光x射线，这些射线来自晶种结构中存在的铌，但它们的产率不足以将剂量率常数降低到。可能需要额外测定剂量率常数，以确定AAPM推荐的粒子常规临床使用共识值。
The aim of this work was to conduct an independent determination of the dose rate constant of the newly introduced Model CS‐1 seed. A total of eight seeds were obtained from the seed manufacturer. The air‐kerma strength of each seed was measured by the manufacturer whose calibration is traceable to the air‐kerma strength standard established for the seeds at the National Institute of Standards and Technology ( uncertainty ). The dose rate constant of each seed was measured by two independent methods: One based on the actual photon energy spectrum emitted by the seed using gamma‐ray spectrometry and the other based on the dose‐rate measured by thermoluminescent dosimeter (TLD) in a Solid Water™ phantom. The dose rate constant in water determined by the gamma‐ray spectrometry technique and by the TLD dosimetry are and , respectively, showing excellent agreement with each other. These values, however, are approximately 15% greater than a previously reported value of [Med. Phys. 31, 1529–1538 (2004)]. Although low‐energy fluorescent x rays at 16.6 and 18.7 keV, originating from niobium present in the seed construction, were measured in the energy spectrum of the seeds, their yields were not sufficient to lower the dose rate constant to the value of . Additional determinations of the dose rate constant may be needed to establish an AAPM recommended consensus value for routine clinical use of the seed.