Radiotherapy and Oncology Department, University Hospital Saint Luc, Catholic University of Louvain, 10 av. Hippocrate, 1200 Brussels, Belgium; Centre for Atomic Molecular Physics and Quantum Optics, University of Douala, P.O. Box 8580, Douala, Cameroon.
Phys Med. 2013 Nov;29(6):631-8. doi: 10.1016/j.ejmp.2012.08.004. Epub 2012 Sep 23.
The purpose of the present study is to perform a clinical validation of a new commercial Monte Carlo (MC) based treatment planning system (TPS) for electron beams, i.e. the XiO 4.60 electron MC (XiO eMC). Firstly, MC models for electron beams (4, 8, 12 and 18 MeV) have been simulated using BEAMnrc user code and validated by measurements in a homogeneous water phantom. Secondly, these BEAMnrc models have been set as the reference tool to evaluate the ability of XiO eMC to reproduce dose perturbations in the heterogeneous phantom. In the homogeneous phantom calculations, differences between MC computations (BEAMnrc, XiO eMC) and measurements are less than 2% in the homogeneous dose regions and less than 1 mm shifting in the high dose gradient regions. As for the heterogeneous phantom, the accuracy of XiO eMC has been benchmarked with predicted BEAMnrc models. In the lung tissue, the overall agreement between the two schemes lies under 2.5% for the most tested dose distributions at 8, 12 and 18 MeV and is better than the 4 MeV one. In the non-lung tissue, a good agreement has been found between BEAMnrc simulation and XiO eMC computation for 8, 12 and 18 MeV. Results are worse in the case of 4 MeV calculations (discrepancies ≈ 4%). XiO eMC can predict dose perturbation induced by high-density heterogeneities for 8, 12 and 18 MeV. However, significant deviations found in the case of 4 MeV demonstrate that caution is necessary in using XiO eMC at lower electron energies.
本研究旨在对一种新的商业电子束蒙特卡罗（MC）治疗计划系统（TPS），即 XiO 4.60 电子 MC（XiO eMC），进行临床验证。首先，使用 BEAMnrc 用户代码模拟了电子束（4、8、12 和 18 MeV）的 MC 模型，并在均匀水模体中进行了测量验证。其次，将这些 BEAMnrc 模型作为参考工具，评估 XiO eMC 重现非均匀模体中剂量扰动的能力。在均匀模体计算中，MC 计算（BEAMnrc、XiO eMC）与测量之间的差异在均匀剂量区域小于 2%，在高剂量梯度区域小于 1mm。对于非均匀模体，通过预测的 BEAMnrc 模型对 XiO eMC 的准确性进行了基准测试。在肺组织中，两种方案在最测试的 8、12 和 18 MeV 剂量分布中总体差异小于 2.5%，优于 4 MeV。在非肺组织中，在 8、12 和 18 MeV 下，BEAMnrc 模拟与 XiO eMC 计算之间存在良好的一致性。在 4 MeV 计算的情况下，发现了较好的一致性（差异约为 4%）。XiO eMC 可以预测 8、12 和 18 MeV 时高密度非均匀性引起的剂量扰动。然而，在 4 MeV 的情况下发现了显著的偏差，这表明在使用 XiO eMC 时需要谨慎，特别是在较低的电子能量下。
