Nuclear Engineering and Technology

  • 제48권2호
  • /
  • Pages.525-532
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  • 2016
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  • 1738-5733(pISSN)
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  • 2234-358X(eISSN)
한국원자력학회 (Korean Nuclear Society)
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Measurement of Photo-Neutron Dose from an 18-MV Medical Linac Using a Foil Activation Method in View of Radiation Protection of Patients

  • Yucel, Haluk (Ankara University, Institute of Nuclear Sciences) ;
  • Cobanbas, Ibrahim (Suleyman Demirel University, School of Medicine, Department of Radiation Oncology) ;
  • Kolbasi, Asuman (Ankara University, Institute of Nuclear Sciences) ;
  • Yuksel, Alptug Ozer (Ankara University, Institute of Nuclear Sciences) ;
  • Kaya, Vildan (Suleyman Demirel University, School of Medicine, Department of Radiation Oncology)
  • 투고 : 2014.10.27
  • 심사 : 2015.11.07
  • 발행 : 2016.04.25
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초록

High-energy linear accelerators are increasingly used in the medical field. However, the unwanted photo-neutrons can also be contributed to the dose delivered to the patients during their treatments. In this study, neutron fluxes were measured in a solid water phantom placed at the isocenter 1-m distance from the head of an18-MV linac using the foil activation method. The produced activities were measured with a calibrated well-type Ge detector. From the measured fluxes, the total neutron fluence was found to be $(1.17{\pm}0.06){\times}10^7n/cm^2$ per Gy at the phantom surface in a $20{\times}20cm^2$ X-ray field size. The maximum photo-neutron dose was measured to be $0.67{\pm}0.04$ mSv/Gy at $d_{max}=5cm$ depth in the phantom at isocenter. The present results are compared with those obtained for different field sizes of $10{\times}10cm^2$, $15{\times}15cm^2$, and $20{\times}20cm^2$ from 10-, 15-, and 18-MV linacs. Additionally, ambient neutron dose equivalents were determined at different locations in the room and they were found to be negligibly low. The results indicate that the photo-neutron dose at the patient position is not a negligible fraction of the therapeutic photon dose. Thus, there is a need for reduction of the contaminated neutron dose by taking some additional measures, for instance, neutron absorbing-protective materials might be used as aprons during the treatment.

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참고문헌

  1. A. Alfuraih, M. Chin, N. Spyrou, Measurements of the photonuclear neutron yield of 15 MV medical linear accelerator, J. Radioanal. Nucl. Chem. 278 (2008) 681-684. https://doi.org/10.1007/s10967-008-1504-y
  2. International Commission on Radiological Protection (ICRP 103), The 2007 Recommendations of the International Commission on Radiological Protection, ICRP Publication 103, Ann. ICRP, Elsevier Ltd., The Netherlands, 2007.
  3. C. Ongaro, A. Zanini, U. Nastasi, J. Rodenas, G. Ottaviano, C. Manfredotti, Analysis of photoneutron spectra produced in medical accelerators, Phys. Med. Biol. 45 (2000) L55. https://doi.org/10.1088/0031-9155/45/12/101
  4. A. Nath, A. Boyer, P. La Riviere, R. McCall, K. Price, Neutron measurements around high energy X-ray radiotherapy machine, The American Association of Physicists in Medicine (AAPM), 1986. Report No. 19.
  5. R. Barquero, R. Mendez, H.R. Vega-Carrillo, M.P. Iniguez, T.M. Edwards,Neutron spectra and dosimetric features around an 18 MV linac accelerator, Health Phys. 88 (2005) 48-58. https://doi.org/10.1097/01.HP.0000142500.32040.ac
  6. R.B. Sanz, R.M. Villafane, M. Bayo, H. Vega-Carrilho, Determination of neutron dose to patients from a 18 MV LINAC, Trabajo CB/UEN-07/039, 2001.
  7. W.S. Liu, S.P. Changlai, L.K. Pan, H.C. Tseng, C.Y. Chen, Thermal neutron fluence in a treatment room with a Varian linear accelerator at a medical university hospital, Rad. Phys. Chem. 80 (2011) 917-922. https://doi.org/10.1016/j.radphyschem.2011.03.022
  8. J.R. Palta, K.R. Hogstrom, C. Tannanonta, Neutron leakage measurements from a medical linear accelerator, Med. Phys. 11 (1984) 498. https://doi.org/10.1118/1.595543
  9. PTW [Internet]. [cited 2014 May 6] PTW Freiburg GmbH, Germany. Available from: http://www.ptw.de/acrylic_and_rw3_slab_phantoms0.html.
  10. H. Yucel, A.N. Solmaz, E. Kose, D. Bor, Spectral interference corrections for the measurement of $^{238}U$ in materials rich in thorium by a high resolution ${\gamma}$-ray spectrometry, Appl. Rad. Isot. 67 (2009) 2049-2056. https://doi.org/10.1016/j.apradiso.2009.07.011
  11. S. Jovanovic, A. Dlabac, N. Mihaljevic, ANGLE v2.1-New version of the computer code for semiconductor detector gamma-efficiency calculations, Nucl. Instrum. Meth. Res. A 622 (2010) 385-391. https://doi.org/10.1016/j.nima.2010.02.058
  12. O. Sima, D. Arnold, C. Dovlete, GESPECOR: a versatile tool in gamma-ray spectrometry, J. Radioanal. Nucl. Chem. 248 (2001) 359-364. https://doi.org/10.1023/A:1010619806898
  13. M. Karadag, H. Yucel, Thermal neutron cross-section and resonance integral for $^{164}$Dy(n,${\gamma}$)$^{165}$Dy reaction", Nucl. Instrum. Meth. Res. A 550 (2005) 626-636. https://doi.org/10.1016/j.nima.2005.04.091
  14. ASTM -261, Standard practice for determining neutron fluence, fluence rate, and spectra by radioactivation techniques, Annual Book of American Society for Testing Materials (ASTM) standards 12.02, 2010, pp. 40-49.
  15. M. Karadag, H. Yucel, Measurement of thermal neutron cross-section and resonance integral for $^{186}$W (n, ${\gamma}$)$^{187}$W reaction by the activation method using a single monitor, Ann. Nucl. Energy 31 (2004) 1285-1297. https://doi.org/10.1016/j.anucene.2004.03.004
  16. H. Yucel, H. Karadag, Measurement of thermal neutron cross section and resonance integral for $^{165}$Ho(n, ${\gamma}$) $^{166g}$Ho reaction by the activation method, Ann. Nucl. Energy 32 (2005) 1-11. https://doi.org/10.1016/j.anucene.2004.07.009
  17. K.H. Beckurts, K. Wirtz, Neutron Physics, Springer, New York, 1964.
  18. V. Kolotov, F. De Corte, Compilation of ${k_0}$ and related data for Neutron Activation Analysis (NAA) in the form of an electronic database, Pure Appl. Chem. 76 (2004) 1921-1925. https://doi.org/10.1351/pac200476101921
  19. T. El Nimr, F. De Corte, L. Moens, A. Simonits, J. Hoste, Epicadmium neutron activation analysis (ENAA) based on the $k_0$-comparator method, J. Radioanal. Nucl. Chem. 67 (1981) 421-435. https://doi.org/10.1007/BF02516355
  20. J.K. Tuli, Nuclear wallet cards, 2011.
  21. LARADatabase [Internet]. Nucleide Gammaand Alpha Library, [cited 2014 October 24]. Available: from http://laraweb.free.fr.
  22. M.J. Berger, J.H. Hubbell, S.M. Seltzer, J. Chang, J.S. Coursey, R. Sukumar, D.S. Zucker, K. Olsen, XCOM: Photon Cross Section Database (version 1.5) [Internet]. National Institute of Standards and Technology, Gaithersburg, MD, 2010 [cited 2014 May 15]. Available from: http://physics.nist.gov/xcom.
  23. GESPECOR Software [Internet]. [cited 2014 March 15]. Available from: http://www.gespecor.de/en.
  24. International Commission on Radiological Protection, Conversion coefficients for use in radiological protection against external radiation, ICRP Publication 74, Ann. ICRP 26 (1996) 159-205.
  25. S.M. Hashemi, G. Raisali, M. Taheri, A. Majdabadi, M. Ghafoori, The effect of external wedge on the photoneutron dose equivalent at a high energy medical linac, Nukleonika 56 (2011) 49-51.
  26. L. Paredes, R. Genis, M. Balcazar, L. Tavera, E. Camacho, Fast neutron leakage in 18 MeV medical electron accelerator, Rad. Measurements 31 (1999) 475-478. https://doi.org/10.1016/S1350-4487(99)00199-7
  27. D. Gur, J.C. Rosen, A.G. Bukovitz, A.W. Gill, Fast and slow neutrons in an 18-MV photon beam from a Philips SL/75-20 linear accelerator, Med. Phys. 5 (1978) 221-222. https://doi.org/10.1118/1.594431
  28. A. Esposito, R. Bedogni, L. Lembo, M. Morelli, Determination of the neutron spectra around an 18MV medical LINAC with a passive Bonner sphere spectrometer based on gold foils and TLD pairs, Rad. Measurements 43 (2008) 1038-1043. https://doi.org/10.1016/j.radmeas.2007.10.035
  29. H.R. Vega-Carrillo, B. Hernandez-Almaraz, V.M. Hernandez-Davila, A. Ortiz-Hernandez, Neutron spectrum and doses in a 18 MV LINAC, J. Radioanal. Nucl. Chem. 283 (2010) 261-265. https://doi.org/10.1007/s10967-009-0337-7
  30. K.R. Kase, X.S. Mao, W.R. Nelson, J.C. Liu, J.H. Kleck, M. Elsalim, Neutron fluence and energy spectra around the Varian Clinac 2100C/2300C Medical Accelerator, Health Phys. 74 (1998) 38-47. https://doi.org/10.1097/00004032-199801000-00005
  31. S.F. Kry, R.M. Howell, U. Titt, M. Salehpour, R. Mohan, O.N. Vassiliev, Energy spectra, sources, and shielding considerations for neutrons generated by a flattening filter-free Clinac, Med. Phys. 35 (2008) 1906-1911. https://doi.org/10.1118/1.2905029
  32. O. Chibani, C.M. Ma, Photonuclear dose calculations for highenergy photon beams from Siemens and Varian linacs, Med. Phys. 30 (2003) 1990-2000. https://doi.org/10.1118/1.1590436
  33. N.E. Ipe, S. Roesler, S. Jiang, C. Ma, Neutron measurements for intensity Modulated Radiation therapy. Paper presented at the Engineering in Medicine and Biology Society, Proceedings of the 22nd Annual International Conference of the IEEE, 2000.
  34. N. Khaled, E. Attalla, H. Ammar, W. Khalil, Dosimetry and fast neutron energies characterization of photoneutrons produced in some medical linear accelerators, Radiat. Eff. Defect. S. 166 (2011) 908-917. https://doi.org/10.1080/10420150.2011.585469
  35. S. Zabihinpoor, M. Hasheminia, Calculation of neutron contamination from medical linear accelerator in treatment room, Adv. Studies Theor. Phys. 5 (2011) 421-428.

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