The FLUKA Monte Carlo code coupled with the local effect model for biological calculations in carbon ion therapy
The FLUKA Monte Carlo code coupled with the local effect model for biological calculations in carbon ion therapy
复制标题
DOI：
10.1088/0031-9155/55/15/006
复制
发表时间：
2010-08-07
影响因子：
3.5
通讯作者：
Sommerer, F.
中科院分区：
文献类型：
--
作者：
Mairani, A.;Brons, S.;Sommerer, F.
碳离子治疗的临床蒙特卡罗（MC）计算必须提供吸收和RBE加权剂量。后者定义为剂量与相对生物学效应（RBE）的乘积。在GSI Helmholtzzentrum fur Schwerionenforschung以及海德堡离子治疗中心（HIT），根据局部效应模型（LEM）计算RBE值。在本文中，我们描述了耦合FLUKA MC代码与LEM及其应用程序的剂量和RBE加权剂量计算的两个相反的C-12离子场的叠加在治疗辐射的方法。将所得结果与CHO（中国仓鼠卵巢）细胞存活率的可用实验数据和GSI分析治疗计划代码TRiP 98的结果进行比较。在吸收物理剂量分布的分析和MC计算之间观察到一些差异，这可以通过TRiP 98中用作输入基础数据的水中横向积分深度-剂量分布与FLUKA重新计算的深度-剂量分布之间的差异来解释。另一方面，考虑到物理束建模的差异，CHO细胞存活曲线的基于FLUKA的生物学计算与实验数据以及TRiP 98预测吻合良好。开发的方法将MC运输/相互作用能力与治疗计划系统（TPS）中相同的生物模型相结合，将在HIT使用，以支持分析TPS进行的剂量和RBE加权剂量计算的确认/改进。
Clinical Monte Carlo (MC) calculations for carbon ion therapy have to provide absorbed and RBE-weighted dose. The latter is defined as the product of the dose and the relative biological effectiveness (RBE). At the GSI Helmholtzzentrum fur Schwerionenforschung as well as at the Heidelberg Ion Therapy Center (HIT), the RBE values are calculated according to the local effect model (LEM). In this paper, we describe the approach followed for coupling the FLUKA MC code with the LEM and its application to dose and RBE-weighted dose calculations for a superimposition of two opposed C-12 ion fields as applied in therapeutic irradiations. The obtained results are compared with the available experimental data of CHO (Chinese hamster ovary) cell survival and the outcomes of the GSI analytical treatment planning code TRiP98. Some discrepancies have been observed between the analytical and MC calculations of absorbed physical dose profiles, which can be explained by the differences between the laterally integrated depth-dose distributions in water used as input basic data in TRiP98 and the FLUKA recalculated ones. On the other hand, taking into account the differences in the physical beam modeling, the FLUKA-based biological calculations of the CHO cell survival profiles are found in good agreement with the experimental data as well with the TRiP98 predictions. The developed approach that combines the MC transport/interaction capability with the same biological model as in the treatment planning system (TPS) will be used at HIT to support validation/improvement of both dose and RBE-weighted dose calculations performed by the analytical TPS.