Water equivalence of various materials for clinical proton dosimetry by experiment and Monte Carlo simulation
Water equivalence of various materials for clinical proton dosimetry by experiment and Monte Carlo simulation
复制标题
DOI：
10.1016/j.nima.2010.01.026
复制
发表时间：
2010-07-01
影响因子：
1.4
通讯作者：
Palmans, Hugo
中科院分区：
文献类型：
--
作者：
Al-Sulaiti, Leena;Shipley, David;Palmans, Hugo
将临床质子剂量测定中使用的各种材料的剂量准确转换为水的剂量是基于注量校正因子，考虑了初级质子的衰减和由于非弹性核相互作用而产生的次级粒子。这项工作旨在研究与剂量测定相关的不同目标材料（如聚甲基丙烯酸甲酯（PMMA）、石墨、A-150、铝和铜）在水当量深度（WED）下在 60 和 200 MeV 下的深度剂量分布和相对于水或石墨的注量校正。这是通过比较使用 MCNPX 2.5.0 的蒙特卡罗模拟、分析模型计算和 Clatterbridge 肿瘤中心 (CCO) 在 60 MeV 调制和未调制质子束中的实验测量来完成的。 MCNPX 模拟表明，除铝外，所有材料在 60 和 200 MeV 下对石墨和水的注量修正较小。分析计算表明，所有材料在 200 MeV 下相对于水的注量校正因子均增加了几个百分点。 60 MeV 未调制光束的实验测量表明与 MCNPX 具有良好的一致性。对于调制光束，铝和铜的注量校正因子随着深度的增加而降低至低于统一数的几个百分点，但对于 A-150 而言，注量校正因子几乎保持恒定且统一。 Crown 版权所有 (C) 2010 由 Elsevier B.V. 出版。保留所有权利。
The accurate conversion of dose to various materials used in clinical proton dosimetry to dose-to-water is based on fluence correction factors, accounting for attenuation of primary protons and production of secondary particles due to non-elastic nuclear interactions. This work aims to investigate the depth dose distribution and the fluence correction with respect to water or graphite at water equivalent depths (WED) in different target materials relevant for dosimetry such as polymethyl methacrylate (PMMA), graphite, A-150, aluminium and copper at 60 and 200 MeV. This was done through a comparison between Monte Carlo simulation using MCNPX 2.5.0, analytical model calculations and experimental measurements at Clatterbridge Centre of Oncology (CCO) in a 60 MeV modulated and un-modulated proton beam. MCNPX simulations indicated small fluence corrections for all materials with respect to graphite and water in 60 and 200 MeV except for aluminium. The analytical calculations showed an increase in the fluence correction factor to a few percent for all materials with respect to water at 200 MeV. The experimental measurements for 60 MeV un-modulated beam indicated a good agreement with MCNPX. For the modulated beam the fluence correction factor was found to be decreasing below unity by up to few percent with depth for aluminium and copper but almost constant and unity for A-150. Crown Copyright (C) 2010 Published by Elsevier B.V. All rights reserved.