Evaluation of variance reduction techniques in BEAMnrc Monte Carlo simulation to improve the computing efficiency

Mohammed, Maged; Chakir, E.; Boukhal, H.; Saeed, M.; Bardouni, T. El

doi:10.1016/j.jrras.2016.05.005

Cited by 17 publications

(16 citation statements)

References 9 publications

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“…The variance reduction techniques are a statistical technique to simplify the calculating, reducing the time, variance, and improving the precision simulation 1,3 . EGSnrc applied some of the following variance reduction techniques:…”

Section: Materials and Methods Variance Reduction Techniques In Egsnrcmentioning

confidence: 99%

“…This technique is useful for improving the probability of interaction of a photon with component modules of the accelerator, especially CMs is a thin slab or created from the low-density materials 3,6,9 . A photon forced to interact is split into a scattered photon whose weight is equal to the probability of interaction and an un-scattered photon carrying the remaining weight 2,5,6 .If the parent particle has not been forced to interact NFMAX times yet, these parameters will be pass onto secondary photons, and secondary photon had to interact the remaining number of times 1,6 .…”

Section: Photon Forcingmentioning

confidence: 99%

“…M. Mohammeda et al researched the VRTs available in BEAMnrc for simulation a Saturne43 accelerator of 12 MV photon beam. The obtained results show that employing direction bremsstrahlung photon splitting (DBS) technique alone or combined with other technologies lead to enhance the efficiency in BEAMnrc simulation 3 . Most recently, S. Shanmugasundaram et al used the VRTs to simulate various ion chambers by using EGSnrc Monte Carlo Codes.…”

Section: Introductionmentioning

confidence: 96%

“…It is not only directly affects the efficiency of the calculation but also affects the practicality of the application of simulation. Up to this time, there has been a lot of published research studies are demonstrating that simulation code based on Monte Carlo method can produce excellent results with reasonable uncertainties (MCNP, PENELOPE, EGS,…) [1][2][3][4] . However, one of the issues associated with Monte Carlo simulations is the potentially significant CPU time required to reach the desired statistical uncertainty 1,5 even though the strong growth of technology and the increase dramatically in the speed of computers.…”

Section: Introductionmentioning

confidence: 99%

“…The BEAMnrc is used for simulating the accelerator head, and the DOSXYZnrc is used for calculating the dose distribution 2,6 . This code has provided several VRTs to solve the time problem and increase the efficiency such as mentioned above, including range rejection, photon forcing, bremsstrahlung photon splitting (uniform, selective, and direction)... 1,3,[6][7][8] . The purpose of this study is to apply the VRTs of code EGSnrc for simulating and calculating the running time and the uncertainty for each simulation, from that the efficiency of each simulation model was evaluated.…”

Section: Introductionmentioning

confidence: 99%

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Application of variance reduction techniques in EGSnrc based Monte-Carlo method

Hoang¹,

Tài²,

Luong³

et al. 2019

Sci. Tech. Dev. J.

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Introduction: Monte Carlo (MC) is considered to be the most accurate method to calculate dose distribution in radiation therapy. However, the limitation of MC simulations is the long calculation time to reach the desired statistical uncertainty in the dose calculation as well as in clinical practice. To overcome the above limitations, Variance reduction techniques (VRTs) has developed and shorten the calculation time while maintaining accuracy. Therefore, the purpose of this study is the application of VRTs in code EGSnrc to find the optimal method for accelerator simulation and calculated dose distribution using MC method. Methods: The linear Accelerator HPD Siemens Primus at the General Hospital of Dong Nai had been simulated by using BEAMnrc code and several variance reduction techniques such as: range rejection, photon forcing, bremsstrahlung photon splitting (uniform, selective and direction)... These VRTs were used under the same set of input parameters as histories of 2x108, photon energy of 6 MV, structure, size and material of the phantom… The computational efficiency ε is calculated by the following equation ε = 1/T.σ2 where T is the CUP time of calculation and σ2 is an estimate of the variance, for evaluating and selecting the VRT which gives the best computational efficiency. Results: The results showed a good agreement between the calculated dose and measured ones when applying different VRTs. These techniques were significantly reduced uncertainty in simulation compared the analog cases. Specifically, the efficiency of DBS and UBS improved by more than 90 times and 15 times compared with the analog instances, respectively. Rang rejection and photon forcing techniques also haveimproved the efficiency of simulation, but not significantly. Conclusions: The application of the VRTs for EGSnrc increase the efficiency of the simulation. VRTs is a powerful tool that should be applied for the simulation by code EGSnrc to improve calculation efficiency by reducing simulation time and its variance. Our results show that the direction bremsstrahlung splitting (DBS) gives thebest computational efficiency.

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Section: Materials and Methods Variance Reduction Techniques In Egsnrcmentioning

confidence: 99%