Validation of Geant4 fragmentation for Heavy Ion Therapy
Validation of Geant4 fragmentation for Heavy Ion Therapy
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DOI：
10.1016/j.nima.2017.06.046
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发表时间：
2017-10-11
影响因子：
1.4
通讯作者：
Guatelli, Susanna
中科院分区：
文献类型：
--
作者：
Bolst, David;Cirrone, Giuseppe A. P.;Guatelli, Susanna
近年来，C-12离子治疗因其良好的剂量符合性而受到越来越多的关注。然而，在治疗能量（其可以高达400 MeV/u）下，碳离子产生次级碎片。对于入射的400 MeV/u C-12离子束，近似70%的束将在布拉格峰之前经历碎裂。这些碎片的剂量测定和放射生物学影响必须准确表征，因为它可能导致患者继发性癌症的风险增加以及改变相对生物学有效性。本文研究了Monte Carlo工具包Geant 4中三种不同的核碎裂模型的准确性，即二元核内级联模型（BIC）、量子分子动力学模型（QMD）和列日核内级联模型（INCL++）。该模型的基准对实验数据的原始400 MeV/u的C-12束入射到水幻影，包括碎片产率，角和能量分布。对于碎片产率，三种替代模型与实验测量值的一致性在类似于5%和类似于35%之间，使用“碎片”选项的QMD对于较轻的碎片给出了最佳一致性，但对于较大的碎片具有降低的一致性。对于角分布，INCL++被认为提供了所有元素（氢除外）的模型之间的最佳一致性，而BIC和QMD被认为产生了比实验更宽的分布。BIC和QMD在动能分布方面表现相似，而INCL++与其他模型和实验相比产生较低的能量分布。皇冠版权所有（C）2017由Elsevier B. V.发布。保留所有权利。
C-12 ion therapy has had growing interest in recent years for its excellent dose conformity. However at therapeutic energies, which can be as high as 400 MeV/u, carbon ions produce secondary fragments. For an incident 400 MeV/u C-12 ion beam, similar to 70% of the beam will undergo fragmentation before the Bragg Peak. The dosimetric and radiobiological impact of these fragments must be accurately characterised, as it can result in increasing the risk of secondary cancer for the patient as well as altering the relative biological effectiveness. This work investigates the accuracy of three different nuclear fragmentation models available in the Monte Carlo Toolkit Geant4, the Binary Intranuclear Cascade (BIC), the Quantum Molecular Dynamics (QMD) and the Liege Intranuclear Cascade (INCL++). The models were benchmarked against experimental data for a pristine 400 MeV/u C-12 beam incident upon a water phantom, including fragment yield, angular and energy distribution. For fragment yields the three alternative models agreed between similar to 5 and similar to 35% with experimental measurements, the QMD using the "Frag'' option gave the best agreement for lighter fragments but had reduced agreement for larger fragments. For angular distributions INCL++ was seen to provide the best agreement among the models for all elements with the exception of Hydrogen, while BIC and QMD was seen to produce broader distributions compared to experiment. BIC and QMD performed similar to one another for kinetic energy distributions while INCL++ suffered from producing lower energy distributions compared to the other models and experiment. Crown Copyright (C) 2017 Published by Elsevier B.V. All rights reserved.