نوع مقاله : مقاله پژوهشی
نویسندگان
1 گروه پرتو پزشکی، دانشکده مهندسی هسته‌ای، دانشگاه شهید بهشتی، صندوق پستی: 1983963113، تهران ـ ایران
2 پژوهشگاه علوم و فنون هسته‌ای، سازمان انرژی اتمی ایران، صندوق پستی: 836-14395، تهران ـ ایران
چکیده
یکی از مهمترین مواردی که در پرتوده‌ی نمونه‌ها برای مطالعات فعال‌سازی یا غیر آن در رآکتورهای تحقیقاتی لازم است مدنظر قرار گیرد توزیع سه‌بعدی دز در فضای اطراف قلب است. دزیمترهای ژل- پلیمر علاوه بر امکان تعیین توزیع‌های پیچیده‌ی دز به صورت سه‌بعدی دارای ترکیبی مشابه با بافت بدن بوده و خود به صورت یک فانتوم عمل می‌کنند. تاکنون کمتر به کاربرد دزیمتر ژلی برای تعیین توزیع دز در میدان‌های مخلوط پرتوهای با چگالی خطی یونش مختلف توجه شده است. در این مطالعه دزیمتر ژل- پلیمر PAGAT پس از تولید در آزمایشگاه، تحت تابش میدان مخلوط نوترون- گامای حاصل از شکافت در قلب رآکتور تحقیقاتی تهران، قرار گرفت و پاسخ ژل با استفاده از تصویربرداری تشدید مغناطیسی (MRI) به صورت تغییر در آهنگ بازگشت هسته‌ها مورد بررسی قرار گرفت. پاسخ ژل نسبت به دز جذبی بهنجار شده بررسی شد و از برازش یک دونمایی به داده‌های دز، R2به دست آمد.
ناحیه‌ای از پاسخ که در آن تغییرات R2برحسب دز بهنجار شده خطی بود به عنوان بازه‌ی دینامیکی انتخاب شد و شیب به عنوان معیاری از حساسیت دزیمتر ژل- پلیمر در میدان مخلوط نوترون- گاما در آن بازه به دست آمد. حساسیت دزیمتر به دز بهنجار شده‌ی حاصل از طیف نوترون- گامای حاصل از شکافت برابر با 1.695 s-1 تقریب زده شد. نتایج به دست آمده نشان داد که دزیمتر ژل- پلیمر PAGAT ابزار مناسبی برای تعیین توزیع دز در میدان مخلوط نوترون- گاما است.
تازه های تحقیق
- G.S. Ibbott, Application of gel dosimetry, Journal of Physics, Conference Series, 3 (2004) 58-77.
2. C. Baldock, Y. De Deene, S. Doran, G. Ibbott, A. Jirasek, M. Lepage, K.B. McAuley, M. Oldham, L.J. Schreiner, Polymer gel dosimetry, Phys. Med. Biol, 55 (2010) R1–R63.
3. M. Oldham, Baustert, C. Lordy, A.D. Smith, M. McJury, A.P. Warrington, M.O. Leach, S. Webby, An investigation into the dosimetry of a nine-field tomotherapy irradiation using BANG-gel dosimetry, Phys. Med. Biol, 43 (1998) 1113–1132.
4. Y. De Deene, Essential characteristics of polymer gel dosimeters, Journal of Physics, Conference Series, 3 (2004) 34-57.
5. Y. De Deene, C. Hurley, A. Venning, K. Vergote, M. Mather, B.J. Healy, C. Baldock, A basic study of some normoxic polymer gel dosimeters, Physics in Medicine and Biology, 47 (2002) 3441-3463.
6. M. Oldham, J.H. Siewerdsen, S. Kumar, J. Wong, D.A. Jaffray, Optical-CT gel dosimetry I: Basic investigations, Medical Physics, 40 (4) (2003) 623-634.
7. Tim Olding, Oliver Holmes, L. John Schreiner, Cone beam optical computed tomography for gel dosimetry I: scanner characterization, Phys. Med. Biol, 55 (2010) 2819–2840.
8. M. Hilts, A. Jirasek, C. Duzenli, Technical consideration for implantation of X-ray CT polymer gel dosimetry, Physics in Medicine and Biology, 50 (2005) 1727-1745.
9. M. Hilts, X-Ray computed tomography imaging of polymer gel dosimeters. in Preliminary Proceeding of DOSGEL 2006. Sherbrooke (Quebec), Canada: University of Sherbrooke. (2006).
10. A Crescenti Remo, Jeffrey C Bamber, Mike Partridge, Nigel L Bush, and Steve Webb, Characterization of the ultrasonic attenuation coefficient and its frequency dependence in a polymer gel dosimeter, Phys. Med. Biol, 52 (2007) 6747–6759.
11. Y. De Deene, Fundamentals of MRI measurements for gel dosimetry, Journal of Physics, Conference Series, 3 (2004) 87-114.
12. A.J. Venning, B. Hill, S. Brindha, B.J. Healy, C. Baldock, Investigation of the PAGAT polymer gel dosimeter using magnetic resonance imaging, Physics in Medicine and Biology Printed in the UK, 50 (2005) 3875-3888.
13. M. Lepage, K. McMahon, G.J. Galloway, Y. De Deene, S.A. Back, C. Baldock, Magnetization transfer imaging for polymer gel dosimetry, Physics in Medicine and Biology, 47 (2002) 1881-1890.
14. Cathrine Westbrook and Carolyn Kaut, MRI in Practice. frist ed, ed. Oseney Mead. Oxford, Londan: Oxford Blackwell Scientific Publications, (1993) 168-169.
15. Jerrold T. Bushberg, J. Anthony Seibert, Edwin M. Leidhold, Jhon M. Boone, The essential physics of medical imaging Magnetic resonance imaging. second ed., Baltimore: Williams & Wilkins (1994).
16. M. Lepage, P.M. Jayasekera, S.A. Back, C. Baldock, Dose resolution optimization of polymer gel dosimeters using different monomers, Physics in Medicine and Biology, 46 (2001) 2665-2680.
17. Y. De Deene and C. Baldock, Optimization of multiple spin-echo sequences for 3D polymer gel dosimetry, Physics in Medicine and Biology, 47 (2002) 3117-3141.
18. Lars E Olssontll, Bengt A Wesuin, Annette Franssons, and Bo Nordellf, Diffusion of ferric ions in agarose dosimeter gels, Phys. Med. Bid., 37 (1992).
19. C. Baldock, R.P. Burford, N. Billingham, G.S. Wagner, S. Patval, R.D. Badawi, S.F. Keevil, Experimental procedure for the manufacture and calibration of polyacrylamide gel (PAG) for magnetic resonance imaging (MRI) radiation dosimetry, Physics in Medicine and Biology, 43 (1998) 695-702.
20. P.M. Fong, D.C. Keil, M.D. Does, J.C. Gore, Polymer gels for magnetic resonance imaging of radiation dose distributions at normal room atmosphere, Physics in Medicine and Biology, 46 (12) (2001) 3105-3113.
21. J. Uusi-Simola, S. Savolainen, A. Kangasm¨aki, S. Heikkinen, Study of the relative dose-response of BANG-3R polymer gel dosimeters in epithermal neutron irradiation, Phys. Med. Biol, 48 (2003) 2895–2906.
22. Jouni UusiSimola, Sami Heikkinen, Petri Kotiluoto, Tom Serén, Tiina Seppälä, Iiro Auterinen, Sauli Savolainen, MAGIC polymer gel for dosimetric verification in boron neutron capture therapy, Journal of Applied Clinical Medical Physics, 8 (2) (2007).
23. G. Gambarini, C. Birattari, C. Colombi, L. Pirola, G. Rosi, Fricke gel dosimetry in boron neutron capture therapy, Radiation Protection Dosimetry, 101 (2002) 419-422.
24. G. Gambarini, V. Collia, S. Gay Petrovich, L. Pirola, G. Rosi, In-phantom imaging of all dose components in boron neutron capture therapy by means of gel dosimeters, Applied Radiation and Isotopes, 61 (2004) 759–763.
25. G. Gambarini, S. Agosteo, S. Altieri, S. Bortolussi, M. Carrara, S. Gay, E. Nava, C. Petrovich, G. Rosi, M. Valente1, Dose distributions in phantoms irradiated in thermal columns of two different nuclear reactors, Radiation Protection Dosimetry, 126 (1–4) (2007) 640–644.
26. S.M. Abtahi, M. Shahriari, M. Zahmatkesh, H. Khalafi, Investigation of the Response of PAGAT Polymer Gel Dosimeter for Thermal Neutrons, J. of Nuclear Sci. and Tech., 53 (2010).
27. A. Jirasek, M. Hilts, C. Shaw, P. Baxter, Experimental properties of THPC based normoxic polyacrylamide gels for use in x-ray computed tomography gel dosimetry. in DOSGEL 2006. Sherbrook (Quebec), Canada: University of Sherbrook (2006).
28. H. Gustavsson, A. Karlsson, S.A. Back, L.E. Olsson, P. Haraldsson, P. Engstrom, H. Nystrom, MAGIC-type polymer gel for three-dimensional dosimetry: intensity-modulated radiation therapy verification, Medical Physics, 30(6) (2003) 1264-71.
29. S.M. Abtahi, M. Shahriari, M.H. Zahmatkesh, H. Khalafi, Sh. Akhlaghpoor, S. Bagheri, A new approach to contrast enhancement in MAGICA gel dosimeter image with MRI technique, Iran. J. Radiat. Res., 6(3) (2008) 151-156.
30. Y. De Deene and C. De. Wagter, Artefacts in multi-echo T2 imaging for high-precision gel dosimetry: III. Effects of temperature drift during scanning, Physics in Medicine and Biology, 46 (2001) 2697-2711.
31. Y. De Deene, R. Van de Walle, E. Achten, C. De Wagter, Mathematical analysis and experimental investigation of noise in quantitative magnetic resonance imaging applied in polymer gel dosimetry, Signal Processing, 70 (1998) 85-101.
32. C. Baldock, M. Lepage, S.A. Back, P.J. Murry, P.M. Jayasekera, D. Porter, T. Kron, Dose resolution in radiotherapy gel dosimetry: effect of echo spacing in MRI pulse sequence, Physics in Medicine and Biology, 46 (2001) 449-460.
33. Y. De Deene, K. Vergote, C. Claeys, C. de Wagter, The fundamental radiation properties of normoxic polymer gel dosimeters: a comparison between a methacrylic acid based gel and acrylamide based gels, Phys. Med. Biol., 51 (2006) 653-673.
34. MATLAB®-The Language of Technical Computing. © 1994-2008 The Math Works Inc.
35. Joaquim P. Marques de Sá, Applied Statistics Using SPSS, STATISTICA, MATLAB and R. second ed, New York: Springer (2007).
36. Y. De Deene, P. Hanselaer, C. De Wagter, E. Achten, W. De Neve†, An investigation of the chemical stability of a monomer/polymer gel dosimeter, Phys. Med. Biol., 45 (2000) 859-878.
37. Helen Gustavsson, Sven A° J Ba¨ck, Joakim Medin, Erik Grusell, and Lars E Olsson, Linear energy transfer dependence of a normoxic polymer gel dosimeter investigated using proton beam absorbed dose measurements, Phys. Med. Biol., 49 (2004) 3847–3855.
A. Ertl, A. Berg, M. Zehetmayer, P. Frigo, High-resolution dose profile studies based on MR Imaging withpolymer BANGTM gels in stereotactic radiation techniques, Magnetic Resonance Imaging, 18 (2000) 343–349.
کلیدواژه‌ها
عنوان مقاله [English]
Feasibility Study of Using PAGAT Polymer Gel Dosimeter for 3D Dosimetry Around the Reactor Core
نویسندگان [English]
- S.M Abtahi 1
- S.M. Aghamiri 1
- H Khalafi 2
1
2
چکیده [English]
An important problem for samples irradiation in research reactors is determination of three dimensional dose distributions in the vicinity of reactor core. Polymer gel dosimeters can be used to measure complex three dimensional dose distributions as well as the integrated dose accurately with no dependency on the dose rate. Furthermore, as they are tissue-equivalent, they may be used as a phantom. So far, polymer gel dosimeters have been used for photon, electron, proton, neutron and heavy ions, but there is a lack of application of polymer gel dosimeters for dosimetry of the mixed field of radiation of different linear ionization concentration. In this research, PAGAT polymer gel dosimeters are fabricated in the laboratory and then were irradiated with the mixed neutron gamma field from the fission process of the Tehran Research Reactor. The gel response was determined by the nuclear magnetic resonance imaging technique as a change in the relaxation rate (R2) of the gel dosimeters. The gel response as a function of normalized dose was investigated and a bi-exponential fitting was adjusted to the dose-R2 data. The region with a linear response, is called dynamic range. The slope of the region as the sensitivity of PAGAT gels to the normalized dose resulted from the neutron-gamma mixed field, was estimated to be 1.695 s-1. The results of this research showed that PAGAT polymer gel dosimeter is a useful tool for 3D dose distribution to determine the neutron gamma mixed field.
کلیدواژه‌ها [English]
- PAGAT Polymer Gel Dosimeter
- Reactor Core
- Neutron-Gamma Mixed Field
- Dose Distribution
- G.S. Ibbott, Application of gel dosimetry, Journal of Physics, Conference Series, 3 (2004) 58-77.
2. C. Baldock, Y. De Deene, S. Doran, G. Ibbott, A. Jirasek, M. Lepage, K.B. McAuley, M. Oldham, L.J. Schreiner, Polymer gel dosimetry, Phys. Med. Biol, 55 (2010) R1–R63.
3. M. Oldham, Baustert, C. Lordy, A.D. Smith, M. McJury, A.P. Warrington, M.O. Leach, S. Webby, An investigation into the dosimetry of a nine-field tomotherapy irradiation using BANG-gel dosimetry, Phys. Med. Biol, 43 (1998) 1113–1132.
4. Y. De Deene, Essential characteristics of polymer gel dosimeters, Journal of Physics, Conference Series, 3 (2004) 34-57.
5. Y. De Deene, C. Hurley, A. Venning, K. Vergote, M. Mather, B.J. Healy, C. Baldock, A basic study of some normoxic polymer gel dosimeters, Physics in Medicine and Biology, 47 (2002) 3441-3463.
6. M. Oldham, J.H. Siewerdsen, S. Kumar, J. Wong, D.A. Jaffray, Optical-CT gel dosimetry I: Basic investigations, Medical Physics, 40 (4) (2003) 623-634.
7. Tim Olding, Oliver Holmes, L. John Schreiner, Cone beam optical computed tomography for gel dosimetry I: scanner characterization, Phys. Med. Biol, 55 (2010) 2819–2840.
8. M. Hilts, A. Jirasek, C. Duzenli, Technical consideration for implantation of X-ray CT polymer gel dosimetry, Physics in Medicine and Biology, 50 (2005) 1727-1745.
9. M. Hilts, X-Ray computed tomography imaging of polymer gel dosimeters. in Preliminary Proceeding of DOSGEL 2006. Sherbrooke (Quebec), Canada: University of Sherbrooke. (2006).
10. A Crescenti Remo, Jeffrey C Bamber, Mike Partridge, Nigel L Bush, and Steve Webb, Characterization of the ultrasonic attenuation coefficient and its frequency dependence in a polymer gel dosimeter, Phys. Med. Biol, 52 (2007) 6747–6759.
11. Y. De Deene, Fundamentals of MRI measurements for gel dosimetry, Journal of Physics, Conference Series, 3 (2004) 87-114.
12. A.J. Venning, B. Hill, S. Brindha, B.J. Healy, C. Baldock, Investigation of the PAGAT polymer gel dosimeter using magnetic resonance imaging, Physics in Medicine and Biology Printed in the UK, 50 (2005) 3875-3888.
13. M. Lepage, K. McMahon, G.J. Galloway, Y. De Deene, S.A. Back, C. Baldock, Magnetization transfer imaging for polymer gel dosimetry, Physics in Medicine and Biology, 47 (2002) 1881-1890.
14. Cathrine Westbrook and Carolyn Kaut, MRI in Practice. frist ed, ed. Oseney Mead. Oxford, Londan: Oxford Blackwell Scientific Publications, (1993) 168-169.
15. Jerrold T. Bushberg, J. Anthony Seibert, Edwin M. Leidhold, Jhon M. Boone, The essential physics of medical imaging Magnetic resonance imaging. second ed., Baltimore: Williams & Wilkins (1994).
16. M. Lepage, P.M. Jayasekera, S.A. Back, C. Baldock, Dose resolution optimization of polymer gel dosimeters using different monomers, Physics in Medicine and Biology, 46 (2001) 2665-2680.
17. Y. De Deene and C. Baldock, Optimization of multiple spin-echo sequences for 3D polymer gel dosimetry, Physics in Medicine and Biology, 47 (2002) 3117-3141.
18. Lars E Olssontll, Bengt A Wesuin, Annette Franssons, and Bo Nordellf, Diffusion of ferric ions in agarose dosimeter gels, Phys. Med. Bid., 37 (1992).
19. C. Baldock, R.P. Burford, N. Billingham, G.S. Wagner, S. Patval, R.D. Badawi, S.F. Keevil, Experimental procedure for the manufacture and calibration of polyacrylamide gel (PAG) for magnetic resonance imaging (MRI) radiation dosimetry, Physics in Medicine and Biology, 43 (1998) 695-702.
20. P.M. Fong, D.C. Keil, M.D. Does, J.C. Gore, Polymer gels for magnetic resonance imaging of radiation dose distributions at normal room atmosphere, Physics in Medicine and Biology, 46 (12) (2001) 3105-3113.
21. J. Uusi-Simola, S. Savolainen, A. Kangasm¨aki, S. Heikkinen, Study of the relative dose-response of BANG-3R polymer gel dosimeters in epithermal neutron irradiation, Phys. Med. Biol, 48 (2003) 2895–2906.
22. Jouni UusiSimola, Sami Heikkinen, Petri Kotiluoto, Tom Serén, Tiina Seppälä, Iiro Auterinen, Sauli Savolainen, MAGIC polymer gel for dosimetric verification in boron neutron capture therapy, Journal of Applied Clinical Medical Physics, 8 (2) (2007).
23. G. Gambarini, C. Birattari, C. Colombi, L. Pirola, G. Rosi, Fricke gel dosimetry in boron neutron capture therapy, Radiation Protection Dosimetry, 101 (2002) 419-422.
24. G. Gambarini, V. Collia, S. Gay Petrovich, L. Pirola, G. Rosi, In-phantom imaging of all dose components in boron neutron capture therapy by means of gel dosimeters, Applied Radiation and Isotopes, 61 (2004) 759–763.
25. G. Gambarini, S. Agosteo, S. Altieri, S. Bortolussi, M. Carrara, S. Gay, E. Nava, C. Petrovich, G. Rosi, M. Valente1, Dose distributions in phantoms irradiated in thermal columns of two different nuclear reactors, Radiation Protection Dosimetry, 126 (1–4) (2007) 640–644.
26. S.M. Abtahi, M. Shahriari, M. Zahmatkesh, H. Khalafi, Investigation of the Response of PAGAT Polymer Gel Dosimeter for Thermal Neutrons, J. of Nuclear Sci. and Tech., 53 (2010).
27. A. Jirasek, M. Hilts, C. Shaw, P. Baxter, Experimental properties of THPC based normoxic polyacrylamide gels for use in x-ray computed tomography gel dosimetry. in DOSGEL 2006. Sherbrook (Quebec), Canada: University of Sherbrook (2006).
28. H. Gustavsson, A. Karlsson, S.A. Back, L.E. Olsson, P. Haraldsson, P. Engstrom, H. Nystrom, MAGIC-type polymer gel for three-dimensional dosimetry: intensity-modulated radiation therapy verification, Medical Physics, 30(6) (2003) 1264-71.
29. S.M. Abtahi, M. Shahriari, M.H. Zahmatkesh, H. Khalafi, Sh. Akhlaghpoor, S. Bagheri, A new approach to contrast enhancement in MAGICA gel dosimeter image with MRI technique, Iran. J. Radiat. Res., 6(3) (2008) 151-156.
30. Y. De Deene and C. De. Wagter, Artefacts in multi-echo T2 imaging for high-precision gel dosimetry: III. Effects of temperature drift during scanning, Physics in Medicine and Biology, 46 (2001) 2697-2711.
31. Y. De Deene, R. Van de Walle, E. Achten, C. De Wagter, Mathematical analysis and experimental investigation of noise in quantitative magnetic resonance imaging applied in polymer gel dosimetry, Signal Processing, 70 (1998) 85-101.
32. C. Baldock, M. Lepage, S.A. Back, P.J. Murry, P.M. Jayasekera, D. Porter, T. Kron, Dose resolution in radiotherapy gel dosimetry: effect of echo spacing in MRI pulse sequence, Physics in Medicine and Biology, 46 (2001) 449-460.
33. Y. De Deene, K. Vergote, C. Claeys, C. de Wagter, The fundamental radiation properties of normoxic polymer gel dosimeters: a comparison between a methacrylic acid based gel and acrylamide based gels, Phys. Med. Biol., 51 (2006) 653-673.
34. MATLAB®-The Language of Technical Computing. © 1994-2008 The Math Works Inc.
35. Joaquim P. Marques de Sá, Applied Statistics Using SPSS, STATISTICA, MATLAB and R. second ed, New York: Springer (2007).
36. Y. De Deene, P. Hanselaer, C. De Wagter, E. Achten, W. De Neve†, An investigation of the chemical stability of a monomer/polymer gel dosimeter, Phys. Med. Biol., 45 (2000) 859-878.
37. Helen Gustavsson, Sven A° J Ba¨ck, Joakim Medin, Erik Grusell, and Lars E Olsson, Linear energy transfer dependence of a normoxic polymer gel dosimeter investigated using proton beam absorbed dose measurements, Phys. Med. Biol., 49 (2004) 3847–3855.
A. Ertl, A. Berg, M. Zehetmayer, P. Frigo, High-resolution dose profile studies based on MR Imaging withpolymer BANGTM gels in stereotactic radiation techniques, Magnetic Resonance Imaging, 18 (2000) 343–349.
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