Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
Review
. 2023 Apr 6;28(1):102-113.
doi: 10.5603/RPOR.a2023.0007. eCollection 2023.

The effect of voxelization in Monte Carlo simulation to validate Bragg peak characteristics for a pencil proton beam

Gumec M Gungor Price  1 , Neslihan Sarigul  2
Affiliations
Review

The effect of voxelization in Monte Carlo simulation to validate Bragg peak characteristics for a pencil proton beam

Gumec M Gungor Price et al. Rep Pract Oncol Radiother. .

Abstract

Background: The purpose of this research was to show how the Bragg peak (BP) characteristics were affected by changing the voxel size in longitudinal and transverse directions in Monte Carlo (MC) simulations by using Geant4 and to calculate BP characteristics accurately by considering the voxel size effect for 68 MeV and 235.81 MeV.

Materials and methods: Different interpolation techniques were applied to simulation data to find the closest results to the experimental data.

Results: When the x-size of the voxel was increased 2 times at low energy, the maximum dose increase in the entrance and plateau regions were 17.8% and 17%, respectively, while BP curve shifted to the shallower region, resulting in a 0.5 mm reduction in the curable tumor width (W80pd). At high energy, the maximum dose increase at the entrance and plateau regions were 0.4% and 0.6%, respectively, while it was observed that W80pd did not change. When the y-z sizes of the voxel were increased 2 times at low energy, the maximum dose reduction at the entrance and plateau regions was 3.4%, but no change was observed in W80pd. At high energy, when the y-z sizes of the voxel were increased 2.2 times, the maximum dose reduction at the entrance and plateau regions were 8.9% and 9.1%, respectively, while W80pd increased by 0.5 mm. When linear, cubic spline, and Akima interpolations were applied to the simulation data, it was found that the results closest to the experimental data were obtained for Akima interpolations for both energies.

Conclusion: it has been shown that the voxel size effect for the longitudinal direction was more effective at low energy than at high energy. However, the voxel size effect for the transverse direction was more effective for high energy.

Keywords: Bragg peak; Geant4; Monte Carlo simulations; proton therapy; voxel size effect.

PubMed Disclaimer

Conflict of interest statement

Competing interest The authors declare that they have no known competing financial interests or personal relationships that could have influenced the work reported in this paper.

Figures

Figure 1
Figure 1
Voxelized water phantom with an incident proton beam in the y–z plane. The beam was travelling along the x-axis denoted as “Depth” in the plots shown later. Colours: protons in blue, gammas in green, neutrons in yellow, electrons in red
Figure 2
Figure 2
Beam characteristics of Bragg peak (BP)
Figure 3
Figure 3
Bragg peak (BP) curves obtained using different ionisation energies for 68 MeV (A), 235.81 MeV (B)
Figure 4
Figure 4
Bragg peak (BP) curves from Monte Carlo (MC) simulation were obtained using different x dimensions for 68 MeV (A), 235.81 MeV (B)
Figure 5
Figure 5
Bragg peak (BP) curves from Monte Carlo (MC) simulation were obtained using different y–z sizes for 68 MeV (A), 235.81 MeV (B)
See this image and copyright information in PMC

Similar articles

See all similar articles

Cited by

References

    1. Schippers JM, Lomax AJ. Emerging technologies in proton therapy. Acta Oncol. 2011;50(6):838–850. doi: 10.3109/0284186X.2011.582513. - DOI - PubMed
    1. Newhauser WD, Zhang R. The physics of proton therapy. Phys Med Biol. 2015;60(8):R155–R209. doi: 10.1088/0031-9155/60/8/R155. - DOI - PMC - PubMed
    1. Pedroni E, Bacher R, Blattmann H, et al. The 200-MeV proton therapy project at the Paul Scherrer Institute: conceptual design and practical realization. Med Phys. 1995;22(1):37–53. doi: 10.1118/1.597522. - DOI - PubMed
    1. Kimstrand P, Traneus E, Ahnesjö A, et al. A beam source model for scanned proton beams. Phys Med Biol. 2007;52(11):3151–3168. doi: 10.1088/0031-9155/52/11/015. - DOI - PubMed
    1. Liu H, Chang JY. Proton therapy in clinical practice. Chin J Cancer. 2011;30(5):315–326. doi: 10.5732/cjc.010.10529. - DOI - PMC - PubMed

LinkOut - more resources