Department of Medical Physics in Radiation Oncology, German Cancer Research Center (DKFZ), Heidelberg 69120, Germany.
Phys Med Biol. 2009 Nov 21;54(22):N509-17. doi: 10.1088/0031-9155/54/22/N01. Epub 2009 Oct 28.
Monte Carlo codes are widely used to simulate dose distributions in ion radiotherapy. The benchmark of the implemented physical models against experimental data plays an important role in improving the accuracy of the simulations. To estimate the accuracy of the inelastic cross sections in SHIELD-HIT, the simulated charge is compared to measured data from a Multi Layer Faraday Cup. In addition, the results are compared to GEANT4, which are already published. Furthermore, energy distributions are simulated with SHIELD-HIT07 and GEANT4.8.1. From a comparison of depth distributions and beam profiles of 100 and 200 MeV protons, we estimate the level of agreement of the two codes. Nuclear interactions predicted by SHIELD-HIT underestimate the total amount of measured charge. The energy distributions from SHIELD-HIT and GEANT4 show differences exceeding the statistical uncertainties of 2%. Due to a difference of the Bragg curve of 0.5 +/- 0.3 mm on average, the mean difference in dose is 3.5% with a maximum deviation of 7% for the simulated cases.
蒙特卡罗代码被广泛用于模拟离子放射治疗中的剂量分布。实施的物理模型与实验数据的基准对比对于提高模拟的准确性起着重要作用。为了估计 SHIELD-HIT 中非弹性截面的准确性，模拟的电荷与来自多层法拉第杯的测量数据进行了比较。此外，结果还与已经发表的 GEANT4 进行了比较。此外，还使用 SHIELD-HIT07 和 GEANT4.8.1 模拟了能量分布。通过比较 100 和 200 MeV 质子的深度分布和束流轮廓，我们估计了这两个代码的一致性水平。由 SHIELD-HIT 预测的核相互作用低估了测量电荷的总量。SHIELD-HIT 和 GEANT4 的能量分布差异超过了 2%的统计不确定性。由于布拉格曲线的平均差异为 0.5 +/- 0.3 毫米，因此模拟情况下的剂量平均差异为 3.5%，最大偏差为 7%。
