Monte Carlo (MC)‐based treatment planning requires a choice of dose voxel size (DVS) and statistical uncertainty (SU). These parameters effect both the precision of displayed dose distribution and time taken to complete a calculation. For efficient, accurate, and precise treatment planning in a clinical setting, optimal values should be selected. In this investigation, 30 volumetric modulated arc therapy (VMAT) stereotactic radiotherapy (SRT) treatment plans, 10 brain, 10 lung, and 10 spine were calculated in the Monaco 5.11.02 treatment planning system (TPS). Each plan was calculated with a DVS of 0.1 and 0.2 cm using SU values of 0.50%, 0.75%, 1.00%, 1.50%, and 2.00%, along with a ground truth calculation using a DVS of 0.1 cm and SU of 0.15%. The variance at each relative dose level was calculated for all SU settings to assess their relationship. The variation from the ground truth calculation for each DVS and SU combination was determined for a range of DVH metrics and plan quality indices along with the time taken to complete the calculations. Finally, the effect of defining the maximum dose using a volume of 0.035 cc was compared to 0.100 cc when considering DVS and SU settings. Changes in the DVS produced greater variations from the ground truth calculation than changes in SU across the values tested. Plan quality metrics and mean dose values showed less sensitivity to changes in SU than DVH metrics. From this study, it was concluded that while maintaining an average calculation time of <10 min, 75% of plans could be calculated with variations of <2.0% from their ground truth values when using an SU setting of 1.50% and a DVS of 0.1 cm in the case of brain or spine plans, and a 0.2 cm DVS in the case of lung plans.

中文翻译：

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建议的剂量体素大小和统计不确定性参数，用于立体定向放疗中的蒙特卡洛剂量计算精度

基于蒙特卡洛（MC）的治疗计划需要选择剂量体素大小（DVS）和统计不确定性（SU）。这些参数影响显示剂量分布的精度和完成计算所需的时间。为了在临床环境中进行有效，准确和精确的治疗计划，应选择最佳值。在这项调查中，在摩纳哥5.11.02治疗计划系统（TPS）中计算了30种体积调制电弧治疗（VMAT）立体定向放射治疗（SRT）治疗计划，10种脑，10肺和10根脊柱。使用0.50％，0.75％，1.00％，1.50％和2.00％的SU值使用0.1和0.2 cm的DVS计算每个计划，并使用0.1 cm的DVS和0.15％的SU计算地面实况。计算所有SU设置的每个相对剂量水平的方差，以评估它们之间的关系。针对一系列DVH指标和计划质量指标以及完成计算所需的时间，确定了每种DVS和SU组合与地面真实计算的差异。最后，在考虑DVS和SU设置时，将使用0.035 cc体积定义最大剂量的效果与0.100 cc进行了比较。DVS的变化比实测值在SU上的变化比地面实况计算产生的变化更大。计划质量指标和平均剂量值显示出对SU变化的敏感性低于DVH指标。从这项研究得出的结论是，在保持平均计算时间<10分钟的同时，可以计算变化小于2的计划的75％。