Limits...
Comparison of electromagnetic and hadronic models generated using Geant 4 with antiproton dose measured in CERN.

Tavakoli MB, Reiazi R, Mohammadi MM, Jabbari K - J Med Phys (2015 Apr-Jun)

Bottom Line: Among available simulation codes, Geant4 provides acceptable flexibility and extensibility, which progressively lead to the development of novel Geant4 applications in research domains, especially modeling the biological effects of ionizing radiation at the sub-cellular scale.Although, with some models our results were promising, the Bragg peak level remained as the point of concern for our study.It is concluded that the Bertini model with high precision neutron tracking (QGSP_BERT_HP) is the best to match the experimental data though it is also the slowest model to simulate events among the physics lists.

View Article: PubMed Central - PubMed

Affiliation: Department of Medical Physics, Isfahan University of Medical Science, Isfahan, Iran.

ABSTRACT
After proposing the idea of antiproton cancer treatment in 1984 many experiments were launched to investigate different aspects of physical and radiobiological properties of antiproton, which came from its annihilation reactions. One of these experiments has been done at the European Organization for Nuclear Research known as CERN using the antiproton decelerator. The ultimate goal of this experiment was to assess the dosimetric and radiobiological properties of beams of antiprotons in order to estimate the suitability of antiprotons for radiotherapy. One difficulty on this way was the unavailability of antiproton beam in CERN for a long time, so the verification of Monte Carlo codes to simulate antiproton depth dose could be useful. Among available simulation codes, Geant4 provides acceptable flexibility and extensibility, which progressively lead to the development of novel Geant4 applications in research domains, especially modeling the biological effects of ionizing radiation at the sub-cellular scale. In this study, the depth dose corresponding to CERN antiproton beam energy by Geant4 recruiting all the standard physics lists currently available and benchmarked for other use cases were calculated. Overall, none of the standard physics lists was able to draw the antiproton percentage depth dose. Although, with some models our results were promising, the Bragg peak level remained as the point of concern for our study. It is concluded that the Bertini model with high precision neutron tracking (QGSP_BERT_HP) is the best to match the experimental data though it is also the slowest model to simulate events among the physics lists.

No MeSH data available.


Related in: MedlinePlus

Antiproton flux calculated by different physics list normalized to the primary antiproton flux at the entrance level. Vertical and horizontal axis represents relative flux (arbitrary unite) and equivalent depth of water (millimeter) respectively
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Figure 4: Antiproton flux calculated by different physics list normalized to the primary antiproton flux at the entrance level. Vertical and horizontal axis represents relative flux (arbitrary unite) and equivalent depth of water (millimeter) respectively

Mentions: Figure 3 illustrates particle flux for secondary particles such as gamma, pions (π +, π−, and π0), kaons (K +, K−, K0), neutron, electron, positron, deuteron, alpha and triton. It was shown that different models calculated different particle flux, which resulted in greater discrepancy on the calculated dose consequently. Figure 4 illustrates the relative antiproton flux to the entrance primary particle flux calculated by different physics lists. As it was shown, there is the significant difference on antiproton flux using CHIPS and QGSC_CHIPS models which agree with the calculated dose showed in Figure 1. Also there was not any significant difference on particle flux calculated by QGSP_BIC, QGSP_BERT, QGSP_BERT_EMV and QGSP_BERT_EMX which agree with the Percentage Depth Dose (PDD) curves in Figure 2.


Comparison of electromagnetic and hadronic models generated using Geant 4 with antiproton dose measured in CERN.

Tavakoli MB, Reiazi R, Mohammadi MM, Jabbari K - J Med Phys (2015 Apr-Jun)

Antiproton flux calculated by different physics list normalized to the primary antiproton flux at the entrance level. Vertical and horizontal axis represents relative flux (arbitrary unite) and equivalent depth of water (millimeter) respectively
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4478644&req=5

Figure 4: Antiproton flux calculated by different physics list normalized to the primary antiproton flux at the entrance level. Vertical and horizontal axis represents relative flux (arbitrary unite) and equivalent depth of water (millimeter) respectively
Mentions: Figure 3 illustrates particle flux for secondary particles such as gamma, pions (π +, π−, and π0), kaons (K +, K−, K0), neutron, electron, positron, deuteron, alpha and triton. It was shown that different models calculated different particle flux, which resulted in greater discrepancy on the calculated dose consequently. Figure 4 illustrates the relative antiproton flux to the entrance primary particle flux calculated by different physics lists. As it was shown, there is the significant difference on antiproton flux using CHIPS and QGSC_CHIPS models which agree with the calculated dose showed in Figure 1. Also there was not any significant difference on particle flux calculated by QGSP_BIC, QGSP_BERT, QGSP_BERT_EMV and QGSP_BERT_EMX which agree with the Percentage Depth Dose (PDD) curves in Figure 2.

Bottom Line: Among available simulation codes, Geant4 provides acceptable flexibility and extensibility, which progressively lead to the development of novel Geant4 applications in research domains, especially modeling the biological effects of ionizing radiation at the sub-cellular scale.Although, with some models our results were promising, the Bragg peak level remained as the point of concern for our study.It is concluded that the Bertini model with high precision neutron tracking (QGSP_BERT_HP) is the best to match the experimental data though it is also the slowest model to simulate events among the physics lists.

View Article: PubMed Central - PubMed

Affiliation: Department of Medical Physics, Isfahan University of Medical Science, Isfahan, Iran.

ABSTRACT
After proposing the idea of antiproton cancer treatment in 1984 many experiments were launched to investigate different aspects of physical and radiobiological properties of antiproton, which came from its annihilation reactions. One of these experiments has been done at the European Organization for Nuclear Research known as CERN using the antiproton decelerator. The ultimate goal of this experiment was to assess the dosimetric and radiobiological properties of beams of antiprotons in order to estimate the suitability of antiprotons for radiotherapy. One difficulty on this way was the unavailability of antiproton beam in CERN for a long time, so the verification of Monte Carlo codes to simulate antiproton depth dose could be useful. Among available simulation codes, Geant4 provides acceptable flexibility and extensibility, which progressively lead to the development of novel Geant4 applications in research domains, especially modeling the biological effects of ionizing radiation at the sub-cellular scale. In this study, the depth dose corresponding to CERN antiproton beam energy by Geant4 recruiting all the standard physics lists currently available and benchmarked for other use cases were calculated. Overall, none of the standard physics lists was able to draw the antiproton percentage depth dose. Although, with some models our results were promising, the Bragg peak level remained as the point of concern for our study. It is concluded that the Bertini model with high precision neutron tracking (QGSP_BERT_HP) is the best to match the experimental data though it is also the slowest model to simulate events among the physics lists.

No MeSH data available.


Related in: MedlinePlus