Wendykier Jacek, Wojtyna Ewa, Bekman Barbara, Bekman Adam, Woźniak Bożena, Niewiadomska Beata, Prażmowska Joanna, Wendykier Piotr, Bieniasiewicz Marcin, Grządziel Aleksandra
Radiotherapy Planning Department, Maria Skłodowska-Curie National Research Institute of Oncology, Gliwice Branch, Gliwice, Poland.
Department of Medical Physics, St. John of Dukla Cancer Center, Lublin, Poland.
Rep Pract Oncol Radiother. 2023 Jul 25;28(3):416-428. doi: 10.5603/RPOR.a2023.0044. eCollection 2023.
The aim of this study was to indicate the most favorable - in terms of to the time of calculation and the uncertainty of determining the dose distribution - values of the parameters for the Electron Monte Carlo (eMC) algorithm in the Eclipse treatment planning system.
Using the eMC algorithm and the variability of the values of its individual parameters, calculations of the electron dose distribution in the full-scattering virtual water phantom were performed, obtaining percentage depth doses, beam profiles, absolute dose values in points and calculation times. The reference data included water tank measurements such as relative dose distributions and absolute point doses.
For 63 sets of calculation data created from selected values of the parameters for the eMC algorithm, calculation times were analyzed and the absolute calculated and measured doses were compared. Performing a statistical analysis made it possible to determine whether the differences in the values of deviations between the actual dose and the calculated dose in individual regions of the percentage depth dose curve and the beam profile are statistically significant between the analyzed sets of parameters.
Taking into account obtained results from the analysis of the discrepancy between the distribution of the calculated and measured dose, the correspondence of the absolute value of the calculated and measured dose and the duration of the calculation of the dose distribution, the optimal set of parameters was indicated for the eMC algorithm which allows obtaining the dose distribution and the number of monitor units in an acceptable time.
本研究的目的是在计算时间和确定剂量分布的不确定性方面，指出Eclipse治疗计划系统中电子蒙特卡罗（eMC）算法参数的最有利值。
利用eMC算法及其各个参数值的变异性，在全散射虚拟水模体中进行电子剂量分布计算，得到百分深度剂量、射野剂量分布、各点的绝对剂量值和计算时间。参考数据包括水箱测量结果，如相对剂量分布和绝对点剂量。
对于从eMC算法的选定参数值创建的63组计算数据，分析了计算时间，并比较了计算得到的绝对剂量和测量剂量。通过进行统计分析，可以确定在百分深度剂量曲线和射野剂量分布的各个区域中，实际剂量与计算剂量之间偏差值的差异在所分析的参数集之间是否具有统计学意义。
考虑到计算剂量与测量剂量分布差异分析、计算剂量与测量剂量绝对值的对应关系以及剂量分布计算持续时间的分析结果，确定了eMC算法的最佳参数集，该参数集能够在可接受的时间内获得剂量分布和监测单位数。
