A Comparison between GATE and MCNPX monte carlo codes in simulation of medical linear accelerator

Abstract

Radiotherapy dose calculations can be evaluated by Monte Carlo (MC) simulations with acceptable accuracy for dose prediction in complicated treatment plans. In this work, Standard, Livermore and Penelope electromagnetic (EM) physics packages of GEANT4 application for tomographic emission (GATE) 6.1 were compared versus Monte Carlo N-Particle eXtended (MCNPX) 2.6 in simulation of 6 MV photon Linac. To do this, similar geometry was used for the two codes. The reference values of percentage depth dose (PDD) and beam profiles were obtained using a 6 MV Elekta Compact linear accelerator, Scanditronix water phantom and diode detectors. No significant deviations were found in PDD, dose profile, energy spectrum, radial mean energy and photon radial distribution, which were calculated by Standard and Livermore EM models and MCNPX, respectively. Nevertheless, the Penelope model showed an extreme difference. Statistical uncertainty in all the simulations was <1%, namely 0.51%, 0.27%, 0.27% and 0.29% for PDDs of 10 cm2× 10 cm2 filed size, for MCNPX, Standard, Livermore and Penelope models, respectively. Differences between spectra in various regions, in radial mean energy and in photon radial distribution were due to different cross section and stopping power data and not the same simulation of physics processes of MCNPX and three EM models. For example, in the Standard model, the photoelectron direction was sampled from the Gavrila-Sauter distribution, but the photoelectron moved in the same direction of the incident photons in the photoelectric process of Livermore and Penelope models. Using the same primary electron beam, the Standard and Livermore EM models of GATE and MCNPX showed similar output, but re-tuning of primary electron beam is needed for the Penelope model.

Comparing 2 Monte Carlo Systems in Use for Proton Therapy Research

“…The 3, 2-dimensional slices selected in Table 1 show that TOPAS and MC 2 agree to within that standard. Both codes have been found to agree well, similar to the results previously reported [15][16][17][18]. We conclude that the different results calculated by each code are not clinically significant in the geometries we simulated.…”

“…Variations in dose calculations when using different Monte Carlo systems must be expected and evaluated. Comparing computational results between 2 or more codes has a well-established precedent [15][16][17][18]. MC simulations are being increasingly adopted for both clinical and research use in proton therapy.…”

Study of a New Design of P-N Semiconductor Detector Array for Nuclear Medicine Imaging by Monte Carlo Simulation Codes

“…As powerful and multi-potential MCNP code could be used to simulate different radiation physics phenomena and get the selective parameters,[8] it is tried to simulate a P-N semiconductor detector made of a P-type NiO with Li impurities (P-NiO: Li) and N-type SnO 2 with F impurities N-SnO 2 :F[9] to be used for nuclear radiation detection. Pulse height distribution of that has been determined with F8 tally in MCNP code as described by Rσdenas et al .…”

Comparison of Air-Gaps Effect in a Small Cavity on Dose Calculation for 6 MV Linac

“…The particle transport is reliant on the energy and the materials interacting with it and is a complicated process. Thus, the accuracy of the MC codes depends on their inner accuracy in particle transport and the precision of the user utilizing the code [ 7 ]. The MC codes are inherently time-consuming methods and it is their major weakness.…”