Dosimetric evaluation of a glass dosimeter for proton beam measurements
Dosimetric evaluation of a glass dosimeter for proton beam measurements
复制标题
DOI：
10.1016/j.apradiso.2012.04.007
复制
发表时间：
2012-08-01
影响因子：
1.6
通讯作者：
Park, Sung Yong
中科院分区：
文献类型：
--
作者：
Rah, Jeong-Eun;Oh, Do Hoon;Park, Sung Yong
目的：GD-301辐射光致发光玻璃剂量计系统最近已上市。本研究的目的是探讨该系统的剂量学特性（重复性，线性，剂量率，衰落，角度依赖性，和深度剂量分布）的临床剂量学在高能质子束，并比较它与氟化锂的REX-100。材料和方法：与GEANT 4蒙特-卡罗模拟的深度剂量分布进行了比较与玻璃剂量计测量。所有测量均在韩国国家癌症中心的质子束（IBA质子治疗系统-Proteus 235）中进行。使用专门为此研究设计的阶梯形保持器在水模体中辐照剂量计。最大高度为100 mm，每10层1 mm的台阶。结果：在200 MeV质子束的玻璃剂量计的重现性在1.5%以内，TLD芯片的响应在1.7%以内。玻璃剂量计信号在1-10戈伊范围内与所施加的剂量呈线性关系。两种剂量计的剂量率依赖性均在1.5%以内。玻璃剂量计的褪色效应被发现是在1.6%以内的6个月。玻璃剂量计的角度依赖性被测量为约1.3%的角度是80度的光束轴使用圆柱体模。在非调制和调制质子束的深度剂量分布与玻璃剂量计得到的估计是在3.0%以内低于电离室和模拟模型使用GEANT 4代码测量。由电离室、玻璃剂量计和GEANT 4模拟确定的布拉格峰深度分别为84.8 mm、84.2 mm和85.0 mm。对于调制质子束，从玻璃剂量计获得的90%近端和远端剂量水平之间的SOBP宽度为48.1 mm。用电离室测量的SOBP宽度为52.2 mm。结论：测量比较玻璃剂量计和MEBO-100剂量测定特性证明了在高能质子束治疗中使用玻璃剂量计进行剂量测量的适用性。(c)2012爱思唯尔有限公司保留所有权利。
Purpose: The GD-301 radiophotoluminescent glass dosimeter system has recently become commercially available. The purpose of this study was to investigate the dosimetric characteristics (reproducibility, linearity, dose rate, fading, angular dependence, and depth-dose distribution) of this system for clinical dosimetry in a high-energy proton beam and to compare it with lithium fluoride TLD-100.Materials and methods: The depth-dose distribution measured with the glass dosimeter was compared to those from GEANT4 Monte-Carlo simulation. All measurements were performed in a proton beam (IBA Proton Therapy System-Proteus 235) at the National Cancer Center in Korea. Dosimeters were irradiated in a water phantom using a stair-shaped holder specially designed for this study. Maximum height was 100 mm with 1 mm steps in each of ten-tiers.Results: Reproducibility in the 200 MeV proton beam was within 1.5% for the glass dosimeter, and within 1.7% for TLD-chip responses. The glass dosimeter signal was linear as a function of applied dose in the range of 1-10 Gy. The dose rate dependence of both dosimeters was within 1.5%. The fading effect of the glass dosimeter was found to be within 1.6% for 6 months. Angular dependence of the glass dosimeter was measured to be approximately 1.3% for angles that were 80 degrees from the beam axis using a cylindrical phantom. Depth-dose distributions in the non-modulated and modulated proton beams obtained with the glass dosimeter were estimated to be within 3.0% lower than those measured with the ionization chamber and simulation model using GEANT4 code. The Bragg peak depths determined from the ionization chamber, the glass dosimeter and GEANT4 simulation were 84.8 mm, 84.2 mm and 85.0 mm, respectively. For the modulated proton beam, the SOBP width between the 90% proximal and the distal dose levels as obtained from the glass dosimeter was 48.1 mm. The SOBP width measured with the ionization chamber was 52.2 mm.Conclusions: Measurements comparing the glass dosimeter and TLD-100 dosimetric characteristics demonstrated the suitability of use of the glass dosimeter for dose measurement in high-energy proton beam therapy. (c) 2012 Elsevier Ltd. All rights reserved.