Clinical implementation of a Monte Carlo treatment planning system
Clinical implementation of a Monte Carlo treatment planning system
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DOI：
10.1118/1.598729
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发表时间：
1999-10-01
期刊：
影响因子：
3.8
通讯作者：
Boyer, AL
中科院分区：
文献类型：
--
作者：
Ma, CM;Mok, E;Boyer, AL
本研究的目的是将蒙特卡罗方法应用于临床放射治疗剂量计算。我们使用EGS4/BEAM程序获得了Varian Clinac 1800、2100C和2300CD加速器6-20 MeV电子束和4、6和15 mV光子束的相空间数据。用多源模型重建了电子束和光子束的相空间数据，保持了蒙特卡罗束流数据的准确性。多源模型将相空间数据存储需求减少了1000倍，加速器模拟时间减少了10倍或更多。在不同的射野大小、源表面距离和束流调制下，蒙特卡罗计算结果与均匀和非均匀体模中剂量分布的测量结果之间的一致性在2%以内。对于不同的治疗野，蒙特卡罗计算的电子输出因子都在实测值的2%以内，而对于不同的肺和骨骼模体，光子和电子束的异质性校正因子分别在1%和2%以内。使用EGS4/DOSXYZ蒙特卡罗程序计算体模和患者的剂量。将结果与常规治疗计划系统和强度调制放射治疗逆计划系统产生的剂量分布进行了比较。在蒙特卡罗计算和商业系统中实施的分析计算之间发现了显著的差异(剂量上的>；5%和等剂量线上的>；5 mm偏移)。剂量差异最大的治疗地点是头颈部、肺和乳房病例。(C)1999年美国物理学家医学协会。[S0094-2405(99)00710-5]。
The purpose of this study was to implement the Monte Carlo method for clinical radiotherapy dose calculations. We used the EGS4/BEAM code to obtain the phase-space data for 6-20 MeV electron beams and 4, 6, and 15 MV photon beams for Varian Clinac 1800, 2100C, and 2300CD accelerators. A multiple-source model was used to reconstruct the phase-space data for both electron and photon beams, which retained the accuracy of the Monte Carlo beam data. The multiple-source model reduced the phase-space data storage requirement by a factor of 1000 and the accelerator simulation time by a factor of 10 or more. Agreement within 2% was achieved between the Monte Carlo calculations and measurements of the dose distributions in homogeneous and heterogeneous phantoms for various field sizes, source-surface distances, and beam modulations. The Monte Carlo calculated electron output factors were within 2% of the measured values for various treatment fields while the heterogeneity correction factors for various lung and bone phantoms were within 1% for photon beams and within 2% for electron beams. The EGS4/DOSXYZ Monte Carlo code was used for phantom and patient dose calculations. The results were compared to the dose distributions produced by a conventional treatment planning system and an intensity-modulated radiotherapy inverse-planning system. Significant differences (>5% in dose and >5 mm shift in isodose lines) were found between Monte Carlo calculations and the analytical calculations implemented in the commercial systems. Treatment sites showing the largest dose differences were for head and neck, lung, and breast cases. (C) 1999 American Association of Physicists in Medicine. [S0094-2405(99)00710-5].