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Evaluation of an electron Monte Carlo dose calculation algorithm for electron beam.

Publication ,  Journal Article
Hu, YA; Song, H; Chen, Z; Zhou, S; Yin, F-F
Published in: J Appl Clin Med Phys
June 23, 2008

The electron Monte Carlo (eMC) dose calculation algorithm of the Eclipse treatment planning system is based heavily upon Monte Carlo simulation of the linac head and modeling of the linac beam characteristics with minimal measurement of beam data. Commissioning of the eMC algorithm on multiple identical linacs provided a unique opportunity to systematically evaluate the algorithm with actual measurements of clinically relevant beam and dose parameters. In this study, measured and eMC calculated dose distributions were compared both along and perpendicular to electron beam direction for electron energy/applicator/depth combination using measurement data from four Varian 21EX CLINAC linear accelerator (Varian Medical System, Palo Alto, CA). Cutout factors for sizes down to 3 x 3 cm were also compared. Comparisons between the measurement and the eMC calculated values show that the R90, R80, R50, and R10 values mostly agree within 3 mm. Measure and Calculated bremsstrahlung dose Dx correlates well statistically although eMC calculated Dx values are consistently smaller than the measured, with maximum discrepancy of 1% for the 20 MeV electron beams. Surface dose agrees mostly within 2%. Field width and penumbra agree mostly within 3mm. Calculation grid size is found to have a significant effect on the dose calculation. A grid size of 5 mm can produce erroneous dose distributions. Using a grid size of 2.5 mm and a 3% accuracy specified for the eMC to stop calculation iteration, the absolute output agrees with measurements within 3% for field sizes of 5 x 5 cm or larger. For cutout of 3 x 3 cm, however, the output disagreement can reach 8%. Our result indicate that eMC algorithm in Eclipse provides acceptable agreement with measurement data for most clinical situations. Calculation grid size of 2.5 mm or smaller is recommended.

Duke Scholars

Published In

J Appl Clin Med Phys

DOI

EISSN

1526-9914

Publication Date

June 23, 2008

Volume

9

Issue

3

Start / End Page

1 / 15

Location

United States

Related Subject Headings

  • Radiotherapy Planning, Computer-Assisted
  • Particle Accelerators
  • Nuclear Medicine & Medical Imaging
  • Monte Carlo Method
  • Electrons
  • Algorithms
  • 5105 Medical and biological physics
  • 3208 Medical physiology
  • 1116 Medical Physiology
  • 1103 Clinical Sciences
 

Citation

APA
Chicago
ICMJE
MLA
NLM
Hu, Y. A., Song, H., Chen, Z., Zhou, S., & Yin, F.-F. (2008). Evaluation of an electron Monte Carlo dose calculation algorithm for electron beam. J Appl Clin Med Phys, 9(3), 1–15. https://doi.org/10.1120/jacmp.v9i3.2720
Hu, Ye Angela, Haijun Song, Zhe Chen, Sumin Zhou, and Fang-Fang Yin. “Evaluation of an electron Monte Carlo dose calculation algorithm for electron beam.J Appl Clin Med Phys 9, no. 3 (June 23, 2008): 1–15. https://doi.org/10.1120/jacmp.v9i3.2720.
Hu YA, Song H, Chen Z, Zhou S, Yin F-F. Evaluation of an electron Monte Carlo dose calculation algorithm for electron beam. J Appl Clin Med Phys. 2008 Jun 23;9(3):1–15.
Hu, Ye Angela, et al. “Evaluation of an electron Monte Carlo dose calculation algorithm for electron beam.J Appl Clin Med Phys, vol. 9, no. 3, June 2008, pp. 1–15. Pubmed, doi:10.1120/jacmp.v9i3.2720.
Hu YA, Song H, Chen Z, Zhou S, Yin F-F. Evaluation of an electron Monte Carlo dose calculation algorithm for electron beam. J Appl Clin Med Phys. 2008 Jun 23;9(3):1–15.

Published In

J Appl Clin Med Phys

DOI

EISSN

1526-9914

Publication Date

June 23, 2008

Volume

9

Issue

3

Start / End Page

1 / 15

Location

United States

Related Subject Headings

  • Radiotherapy Planning, Computer-Assisted
  • Particle Accelerators
  • Nuclear Medicine & Medical Imaging
  • Monte Carlo Method
  • Electrons
  • Algorithms
  • 5105 Medical and biological physics
  • 3208 Medical physiology
  • 1116 Medical Physiology
  • 1103 Clinical Sciences