Factors influencing the electron dose calculation in Eclipse eMC

This study aims to evaluate the factors influencing electron dose calculation in Eclipse electron Monte Carlo (eMC) on virtual phantoms. Each parameter of accuracy, calculation grid size, random number generator seed, number of particle histories, smoothing method and smoothing level in Eclipse eMC was varied while other parameters were fixed in default value. Gamma analysis was used to evaluate dose distribution accuracy. The reference dose distributions were set as the best option values. The 1% accuracy, 1 mm calculation grid size, 2100000000 random generator seed number, 0 number of particle histories, 3D Gaussian smoothing method and strong smoothing level with 2%/2mm criteria were defined as the best option values. The 6 and 18 MeV energy, the sizes of 6x6 cm² and 10x10 cm² applicator were used. The overall results showed the gamma passing rate higher than 90% except when higher accuracy than 2%, 5 mm calculation grid size, no smoothing/low smoothing level and changed the number of particle histories other than 0 were applied. This study shows that the accuracy, calculation grid size, smoothing method, smoothing level and number of particle histories parameters are significantly impact to dose distribution and the first two factors are also affect to calculation time. (paper)