A revised Gaussian pencil beam model for calculation of the in-water dose caused by clinical electron-beam irradiation

Purposes: The dose in water caused by clinical electron-beam irradiation is mainly composed of the doses due to direct electrons, indirect and contaminant X-rays. In this paper, an analytical method for 3-dimensional (3D) calculation electrons direct-plus-indirect proposed light electron Monte Carlo (eMC) datasets. Methods: was performed square fields, based on a revised Gaussian pencil beam model, where parallel depth-dose dataset under infinitely large field reconstructed from fan with finite field. We used semi-infinite phantom, setting incident surface isocenter plane that perpendicular axis. model sets effective at each depth, larger than geometrical applicator forms basis its divergent spread source-surface distance (SSDeff). Results conclusions: By comparing calculated datasets depth (DD) off-axis (OAD) eMC beams E=6, 12, 18 MeV Wieslander Knöös (2006), it has been found practical use bright prospect give almost same results as