Simulation Of Neutron Contamination From Medical Linac Using Particle And Heavy Ions Transport Code System (PHITS)

Bilalodin Bilalodin, Aris Haryadi, Bejo Haryanto

Abstract

A research on neutron contamination in LINAC device has been carried out using a Monte Carlo method. The simulation is based on the Siemens Primus  LINAC machine model whose component consists of  target, primary collimator, flattening filter and secondary collimator as its main components. A neutron contamination examination was carried out using a 10 x 10 cm radiation field and a 100 cm SSD. Subsequently, at a distance of 100 cm from the X-ray source, a water phantom is placed. Investigation of the presence of contaminants was carried out the LINAC operating voltages of 6, 8, 10, 15, 18 and 25 MV. The simulation results show that neutron contamination occurs due to the interaction of photons with the components of the LINAC device, namely the primary collimator, flattening filter and secondary collimator. The operating voltages that can produce neutron contaminant start at 10 MV. Increase in the voltage of the LINAC device causes consequent increase in neutron flux. Such increase in neutron flux has the potential to increase therapeutic dose.

Keywords

Neutron contamination; Neutron flux; LINAC; PHITS

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References

1. Quintieri, L., Bedogni, R., Buonomo, B., Esposito, A., De Giorgi, M., Mazzitelli, G., and Goméz-Ros, J. M. 2012. Photoneutron Source by High Energy Electrons on High Z Target: Comparison between Monte Carlo Codes and Experimental Data. Fusion Science and Technology, 61(1T), 314-321.

2. Hao, J., Magnelli, A., Godley, A., and Jennifer, S. Y. 2019. Use of a Linear Accelerator for Conducting In Vitro Radiobiology Experiments. JoVE (Journal of Visualized Experiments), 147, e59514.

3. Naseri, A., and Mesbahi, A. 2010. A review on photoneutrons characteristics in radiation therapy with high-energy photon beams. Reports of practical oncology and radiotherapy, 15(5), 138-144.

4. Martinez-Ovalle, S. A., Barquero, R., Gomez-Ros, J. M., and Lallena, A. M. 2011. Neutron dose equivalent and neutron spectra in tissue for clinical linacs operating at 15, 18 and 20 MV. Radiation protection dosimetry, 147(4), 498-511.

5. Nedaie, H. A., Darestani, H., Banaee, N., Shagholi, N., Mohammadi, K., Shahvar, A., and Bayat, E. 2014. Neutron dose measurements of Varian and Elekta linacs by TLD600 and TLD700 dosimeters and comparison with MCNP calculations. Journal of medical physics/Association of Medical Physicists of India, 39(1), 10.

6. Thekkedath, S. C., Raman, R. G., Musthafa, M. M., Bakshi, A. K., Pal, R., Dawn, S., and Datta, D. 2016. Study on the measurement of photo-neutron for15 MV photon beam from medical linear accelerator under different irradiation geometries using passive detectors. Journal of Cancer Research and Therapeutics, 12(2), 1060.

7. Abou-Taleb, W. M., Hassan, M. H., El_Mallah, E. A., and Kotb, S. M. 2018. MCNP5 evaluation of photoneutron production from the Alexandria University 15 MV Elekta Precise medical LINAC. Applied Radiation and Isotopes, 135, 184-191.

8. Banaee, N., Goodarzi, K., and Nedaie, H. A. 2021. Neutron contamination in radiotherapy processes: a review study. Journal of Radiation Research, 62(6), 947-954.

9. Hashimoto, S., Iwamoto, O., Iwamoto, Y., Sato, T., and Niita, K. 2015. PHITS simulation of quasi-monoenergetic neutron sources from 7Li (p, n) reactions. Energy Procedia, 71, 191-196.

10 Abou-Taleb, W. M., Hassan, M. H., El_Mallah, E. A., and Kotb, S. M. 2018. MCNP5 evaluation of photoneutron production from the Alexandria University 15 MV Elekta Precise medical LINAC. Applied Radiation and Isotopes, 135, 184-191.

11. Sato, T., Niita, K., Matsuda, N., Hashimoto, S., Iwamoto, Y., Furuta, T., and Sihver, L. 2013. Overview of particle and heavy ion transport code system PHITS. Annals of Nuclear Energy, 82, 110-11

12. Ezzati, A. O., Studenski, M. T., and Gohari, M. 2020. Spatial mesh-based surface source model for the electron contamination of an 18 MV photon beams. Journal of medical physics, 45(4), 221.

13. Almatani, T. 2021). Validation of a 10 MV photon beam Elekta Synergy linear accelerator using the BEAMnrc MC code. Journal of King Saud University-Science, 33(4), 101406

14. Amour, K., Maleka, P., Maunda, K., Mazunga, M., and Msaki, P. 2020. Verification of Depth Dose Curves Derived on Beeswax, Paraffin and Water Phantoms Using FLUKA Monte Carlo Code. Tanzania Journal of Science, 46(3), 923-930.

15. Jabbari, I., and Monadi, S. 2015. Development and validation of MCNPX-based Monte Carlo treatment plan verification system. Journal of medical physics/Association of Medical Physicists of India, 40(2), 80.

16. Bilalodin, B., Suparta, G. B., Hermanto, A., Palupi, D. S., Sardjono, Y., and Rasito, R. 2020. Analysis of particle distribution in a double layer beam shaping assembly resulted from 30 MeV-proton reactions with beryllium target using the PHITS program. Jurnal Teknologi, 82(3).

17. Dawn, S., Pal, R., Bakshi, A. K., Kinhikar, R. A., Joshi, K., Jamema, S. V., and Datta, D. 2018. Evaluation of in-field neutron production for medical LINACs with and without flattening filter for various beam parameters-Experiment and Monte Carlo simulation. Radiation Measurements, 118, 98-107

18. Patil, B. J., Chavan, S. T., Pethe, S. N., Krishnan, R., Bhoraskar, V. N., and Dhole, S. D. 2010. Simulation of e–γ–n targets by FLUKA and measurement of neutron flux at various angles for accelerator based neutron source. Annals of Nuclear Energy, 37(10), 1369-1377.

19. Khaledi, N., Dabaghi, M., Sardari, D., Samiei, F., Ahmadabad, F. G., Jahanfarnia, G., and Wang, X. 2018. Investigation of photoneutron production by Siemens artiste linac: A Monte Carlo Study. Radiation Physics and Chemistry, 153, 98-103.

20 Tai, D. T., Loan, T. T. H., Sulieman, A., Tamam, N., Omer, H., and Bradley, D. A. 2021. Measurement of Neutron Dose Equivalent within and Outside of a LINAC Treatment Vault Using a Neutron Survey Meter. Quantum Beam Science, 5(4), 33.

21. Dowlatabadi, H., Mowlavi, A. A., Ghorbani, M., Mohammadi, S., and Knaup, C. 2020. Study of photoneutron production for the 18 mv photon beam of the siemens medical linac by monte carlo simulation. Journal of Biomedical Physics & Engineering, 10(6), 679.

22. Shahmohammadi Beni, M., Hau, T. C., Krstic, D., Nikezic, D., and Yu, K. N. 2017. Monte Carlo studies on neutron interactions in radiobiological experiments. PLoS One, 12(7), e0181281

DOI: https://doi.org/10.13057/ijap.v12i2.60328

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