A Monte Carlo evaluation for effects of probable dimensional uncertainties of low dose rate brachytherapy seeds on dose

Abstract

Dose TG-43 report Monte Carlo EGSnrc a b s t r a c tThe aim of this study is to determine effects of size deviations of brachytherapy seeds on two dimensional dose distributions around the seed. Although many uncertainties are well known, the uncertainties which stem from geometric features of radiation sources are weakly considered and predicted. Neither TG-43 report which is not completely in common consensus, nor individual scientific MC and experimental studies include sufficient data for geometric uncertainties. Sizes of seed and its components can vary in a manufacturing deviation. This causes geometrical uncertainties, too. In this study, three seeds which have different geometrical properties were modeled using EGSnrc-Code Packages. Seeds were designed with all their details using the geometry package. 5% deviations of seed sizes were assumed. Modified seeds were derived from original seed by changing sizes by 5%. Normalizations of doses which were calculated from three kinds of brachytherapy seed and their derivations were found to be about 3%-20%. It was shown that manufacturing differences of brachytherapy seed cause considerable changes in dose distribution.

Monte Carlo simulation of ruthenium eye plaques with GEANT4: influence of multiple scattering algorithms, the spectrum and the geometry on depth dose profiles

“…Monte Carlo (MC) simulations are a useful tool for the dosimetry of brachytherapy sources. MC simulations can answer questions about the dosimetric measurement processes, such as the detector response (Bohm et al 2001), phantom size (Pérez-Calatayud et al 2004) or the influence of geometrical uncertainties in brachytherapy sources (Camgöz and Kumru 2012). GEANT4 was successfully used to simulate photon-emitting brachytherapy sources (Thiam et al 2008).…”

Evaluation of the usefulness of the electron Monte Carlo algorithm for planning radiotherapy with the use of electron beams

“…In real clinical situations, in case of heterogeneity, large absorbent curvatures and, in the case of a change of SSD, from a distance for which the input data was measured, and at greater distances the Hogstrom algorithm did not provide satisfactory accuracy [2][3][4]. The increasing power of computers and the development of algorithms allowed to implement the Monte Carlo method in the treatment planning systems for electron beams [5][6][7]. This method has been used in the Varian Eclipse treatment planning system [8].…”