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Penumbra width determination of single beam and 201 beams of Gamma Knife machine model 4C using Monte Carlo simulation

Published online by Cambridge University Press:  11 September 2018

Atefeh Mahmoudi
Affiliation:
Department of Medical Physics and Biomedical Engineering, Faculty of Medicine, Tehran University of Medical Sciences, Islamic Republic of Iran
Alireza Shirazi*
Affiliation:
Department of Medical Physics and Biomedical Engineering, Faculty of Medicine, Tehran University of Medical Sciences, Islamic Republic of Iran
Ghazale Geraily*
Affiliation:
Department of Medical Physics and Biomedical Engineering, Faculty of Medicine, Tehran University of Medical Sciences, Islamic Republic of Iran
Tahereh Hadisi nia
Affiliation:
Department of Medical Physics and Biomedical Engineering, Faculty of Medicine, Tehran University of Medical Sciences, Islamic Republic of Iran
Masoume Bakhshi
Affiliation:
Department of Medical Physics and Biomedical Engineering, Faculty of Medicine, Tehran University of Medical Sciences, Islamic Republic of Iran
Maryam Maleki
Affiliation:
Department of Medical Physics and Biomedical Engineering, Faculty of Medicine, Isfahan University of Medical Sciences, Islamic Republic of Iran
*
Author for correspondence: Ghazale Geraily, Department of Medical Physics and Biomedical Engineering, Faculty of Medicine, Tehran University of Medical Sciences, Iran. Email: gh-geraily@sina.tums.ac.ir
Author for correspondence: Ghazale Geraily, Department of Medical Physics and Biomedical Engineering, Faculty of Medicine, Tehran University of Medical Sciences, Iran. Email: gh-geraily@sina.tums.ac.ir

Abstract

Background

One of the stereotactic radiosurgery techniques is Gamma Knife radiosurgery, in which intracranial lesions that are inaccessible or inappropriate for surgery are treated using 201 cobalt-60 sources in one treatment session. In this conformal technique, the penumbra width, which results in out-of-field dose in tumour-adjacent normal tissues should be determined accurately. The aim of this study is to calculate the penumbra widths of single and 201 beams for different collimator sizes of Gamma Knife machine model 4C using EGSnrc/BEAMnrc Monte Carlo simulation code and comparison the results with EBT3 film dosimetry data.

Methods and materials

In this study, simulation of Gamma Knife machine model 4C was performed based on the Monte Carlo codes of EGSnrc/BEAMnrc. To investigate the physical penumbra width (80−20%), the single beam and 201 beams profiles were obtained using EGSnrc/DOSXYZnrc code and EBT3 films located at isocentre point in a spherical Plexiglas head phantom.

Results

Based on the results, the single beam penumbra widths obtained from simulation data for 4, 8, 14 and 18 mm collimator sizes along X axis were 0·75, 0·77, 0·90 and 0·92 mm, respectively. The data for 201 beams obtained from simulation were 2·61, 4·80, 7·92 and 9·81 mm along X axis and 1·31, 1·60, 1·91 and 2·14 mm along Z axis and from film dosimetry were 3·21, 4·90, 8·00 and 10·61 mm along X axis and 1·22, 1·69, 2·01 and 2·25 mm along Z axis, respectively.

Conclusion

The differences between measured and simulated penumbra widths are in an acceptable range. However, for more precise measurement in the penumbra region in which dose gradient is high, Monte Carlo simulation is recommended.

Type
Original Article
Copyright
© Cambridge University Press 2018 

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Footnotes

Cite this article: Mahmoudi A, Shirazi A, Geraily G, Hadisi nia T, Bakhshi M, Maleki M. (2019) Penumbra width determination of single beam and 201 beams of Gamma Knife machine model 4C using Monte Carlo simulation. Journal of Radiotherapy in Practice18: 82–87. doi: 10.1017/S1460396918000407

References

1. Nabavi, M, Nedaie, H A, Salehi, N, Naderi, M. Stereotactic radiosurgery/radiotherapy: a historical review.. IJMP 2014; 11 (1): 156167.Google Scholar
2. Tyler, M, Liu, P Z, Chan, K W et al. Characterization of small-field stereotactic radiosurgery beams with modern detectors. Phys Med Biol 2013; 58 (21): 75957608.Google Scholar
3. Xiong, W, Huang, D, Lee, L et al editors. Implementation of Monte Carlo simulations for the Gamma Knife system. Journal of Physics: Conference Series; 2007: IOP Publishing.Google Scholar
4. Al-Dweri, F M, Lallena, A M. A simplified model of the source channel of the Leksell Gamma Knife®: testing multisource configurations with PENELOPE. Phys Med Biol 2004; 49 (15): 34413453.Google Scholar
5. Moskvin, V, DesRosiers, C, Papiez, L, Timmerman, R, Randall, M, DesRosiers, P. Monte Carlo simulation of the Leksell Gamma Knife®: I. Source modelling and calculations in homogeneous media. Phys Med Biol 2002; 47 (12): 1995.Google Scholar
6. Day, M, Lambert, G, Locks, S. The effect of secondary electron spread on the penumbra in high energy photon beam therapy. Br J Radiol 1990; 63 (748): 278285.Google Scholar
7. Yarahmadi, M, Allahverdi, M, Nedaie, H A, Asnaashari, K, Vaezzadeh, S A, Sauer, O A. Improvement of the penumbra for small radiosurgical fields using flattening filter free low megavoltage beams. Zeitschrift für Medizinische Physik 2013; 23 (4): 291299.Google Scholar
8. O’Malley, L, Pignol, J-P, Beachey, D J, Keller, B M, Presutti, J, Sharpe, M. Improvement of radiological penumbra using intermediate energy photons (IEP) for stereotactic radiosurgery. Phys Med Biol 2006; 51 (10): 2537.Google Scholar
9. Laughlin, J S, Mohan, R, Kutcher, G J. Choice of optimum megavoltage for accelerators for photon beam treatment. Int J Radiat Oncol Biol Phys 1986; 12 (9): 15511557.Google Scholar
10. Oh, S A, Kang, M K, Yea, J W, Kim, S K, Oh, Y K. Study of the penumbra for high-energy photon beams with Gafchromic™ EBT2 films. J Korean Phy Soc 2012; 60 (11): 19731976.Google Scholar
11. Romano, F, Sabini, M, Cuttone, G, Russo, G, Mongelli, V, Foroni, R. editors. Geant4-based Monte Carlo Simulation of the Leksell Gamma Knife®. Nuclear Science Symposium Conference Record, 2007 NSS'07 IEEE; 2007: IEEE.Google Scholar
12. Cheung, J Y, Yu, K, Ho, R T, Yu, C. Monte Carlo calculations and GafChromic film measurements for plugged collimator helmets of Leksell Gamma Knife unit. Med Phys 1999; 26 (7): 12521256.Google Scholar
13. Elekta. Leksell Gamma Knife C, Software upgrade, Instruction for use 2004.Google Scholar
14. Najafi, M, Geraily, G, Shirazi, A, Esfahani, M, Teimouri, J. Analysis of Gafchromic EBT3 film calibration irradiated with gamma rays from different systems: Gamma Knife and Cobalt-60 unit. Med Dosim 2017; 42 (3): 159168.Google Scholar
15. Rogers, D, Walters, B, Kawrakow, I. BEAMnrc users manual. Nrc Report Pirs 2009; 509: 12.Google Scholar
16. Guerrero, M, Li, X A, Ma, L. A technique to sharpen the beam penumbra for Gamma Knife radiosurgery. Phys Med Biol 2003; 48 (12): 1843.Google Scholar
17. Keller, B M, Beachey, D J, Pignol, J P. Experimental measurement of radiological penumbra associated with intermediate energy x‐rays and small radiosurgery field sizes. Med Phys 2007; 34 (10): 39964002.Google Scholar
18. Keller, B M, Pignol, J P, Presutti, J, Beachey, D J. Intermediate energy photons to improve dose gradient, conformality, and homogeneity: Potential benefits for small field intracranial radiosurgery. Med Phys 2009; 36 (1): 3339.Google Scholar
19. Bilge, H, Ozen, Z, Senkesen, O, Kucucuk, H, Cakir, A, Sengoz, M. Determination of output factors for the Leksell gamma knife using ion chamber, thermoluminescence detectors and films. J BUON 2006; 11 (2): 223.Google Scholar
20. Bertolino, N. Experimental validation of Monte Carlo simulation of Leksell Gamma Knife Perfexion stereotactic radiosurgery system. Ms thesis. University of Milan, Milan, Italy. 2008-2009.Google Scholar