European Journal of Biophysics
Volume 2, Issue 6, December 2014, Pages: 72-80
Received: Dec. 29, 2014;
Accepted: Jan. 14, 2015;
Published: Jan. 28, 2015
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Miguel Ángel Chesta, Facultad de Matemática, Astronomía y Física, Universidad Nacional de Córdoba, Córdoba, Argentina; Instituto de Física Enrique Gaviola, Ifeg, CONICET, Córdoba, Argentina
Ana Lucía Poma, Facultad de Matemática, Astronomía y Física, Universidad Nacional de Córdoba, Córdoba, Argentina
Dionisio José Mc Donnell, Departamento de Física Médica, Terapia Radiante Cumbres S.A., Rosario, Argentina
Precise calculations of absorbed dose (AD) are a difficult task involving physical phenomena such as emission, transport, and absorption of radiation. We used the Monte Carlo method to calculate Kerma as well as AD in water imparted by two different Ir-192 HDR brachytherapy seeds (Flexisource and microSelectron-v2) taking into account the AAPM TG-43 formalism and AAPM & ESTRO most recent reports recommendations. The aim of this work is to evaluate when can Kerma be used as a measurement of AD for this type of seeds. Thus, we analyse the behaviour of both quantities in whole space, putting special emphasis near the source surface. We carried out calculations using microvoxels to obtain high spatial resolution of data close to the source. We observed differences of up to 6 % between AD and Kerma within 1 mm around the seed, and less than 1 % in any other region of the phantom. This allows us to analyse build-up region for Ir-192 HDR brachytherapy seeds. As it will be further discussed in this paper, our results can be explained in terms of partial electronic equilibrium reached on different regions of the phantom. Both seeds showed common overall behaviour, providing generality to the conclusions drawn. The complete bearing of the radial dose function (defined in the TG43 formalism) as it traverses the surface of the seed is reported. Whenever comparisons are possible, our results are in agreement with those reported by other authors. Tables of radial dose function, including new data computed from AD rate (instead of Kerma rate), are presented.
Miguel Ángel Chesta,
Ana Lucía Poma,
Dionisio José Mc Donnell,
Kerma and Photons Absorbed-Dose from Ir-192 HDR Seeds, European Journal of Biophysics.
Vol. 2, No. 6,
2014, pp. 72-80.
Pérez-Calatayud J, Ballester F, Das RK, DeWerd LA, Ibbott GS, Meigooni AS, Ouhib Z, Rivard MJ, Sloboda RS and Williamson JF (2012) Dose calculation for photon-emitting brachytherapy sources with average energy higher than 50keV: Report of the AAPM and ESTROMed. Phys. 39(5) 2904-29.
Granero D, Pérez-Calatayud J, Casal E, Ballester F and Venselaar J (2006) A dosimetric study on the Ir-192 high dose rate FlexisourceMed. Phys. 33(12) 4578-82.
Daskalov GM, Georgi M, Löffler E, Williamson JF and Jeffrey F (1998) Monte Carlo-aided dosimetry of a new high dose-rate brachytherapy source Med. Phys. 25(11) 2200-8.
Ballester F, Granero D, Pérez-Calatayud J, Melhus CS and Rivard MJ (2009) Evaluation of high-energy brachytherapy source electronic disequilibriumand dose from emitted electronsMed. Phys. 36(9) 4250-5.
Chen Z and Nath R (2001) Dose rate constant and energy spectrum of interstitial brachytherapy sourcesMed. Phys. 28(1) 86-96.
Luxton G and Jozsef G (1999) Radial dose distribution, dose to water and dose rate constant for mono-energetic photon point sources from 10 keV to 2 MeV: EGS4 Monte Carlo model calculation Med. Phys. 26(12) 2531-8.
Kumar S, Deshpande DD and Nahum AE (2015) Monte-Carlo-derived insights into dose–kerma–collision kerma inter-relationships for 50 keV–25 MeV photon beams in water, aluminium and copper Phys. Med. Biol. 60 501-19.
Nath R, Anderson LL, Luxton G, Weaver KA, Williamson JF and Meigioni AS (1995) Dosimetry of interstitial brachytherapy sources: Recommendations of the AAPM Radiation Therapy Committee Task Group No. 43 Med. Phys. 22 209-234.
Rivard M, Coursey B, DeWerd L, Hanson W, SaifulHuq M, Ibbott G, Mitch M, Nath R and Williamson J (2004) Update of AAPM Task Group No. 43 Report: A revised AAPM protocol for brachytherapy dose calculations Med. Phys. 31 633–74.
Papagiannis P, Angelopoulos A, Pantelis E, Sakelliou L, Baltas D, Karaiskos P, Sandilos P and Vlachos L (2002) Dosimetry comparison of 192 Ir sources Med. Phys. 29(10) 2239–46.
Taylor RE and Rogers DWO (2008) EGSnrc Monte Carlo calculated dosimetry parameters for 192-Ir and 169-Yb brachytherapy sources Med. Phys. 35(11) 4933–44.
Granero D, Vijande J, Ballester F and Rivard M (2011) Dosimetry revisited for the HDR mHDR-v2 Med. Phys. 38(1) 487–94.
Salvat F, Fernandez-Varea J M, Acosta E and Sempau J (2008) PENELOPE—A code system for Monte Carlo simulation of electron and photon transport, Version 2008 OECD Nuclear Energy Agency Issy-les-Moulineaux, available at http://www.nea.fr/html/science/pubs/2009/nea6416-penelope. pdf.
Salvat F, Fernández-Varea JM and Sempau J (2008) PENELOPE-2008: A code system for Monte Carlo simulation of electron and photon transport Workshop Proceedings Barcelona Spain.
Badal A and Sempau J (2006) A package of Linux scripts for the parallelization of Monte Carlo simulations Computer Physics Communications 175 440–50.
Cullen D, Hubbell J and Kissel L (1997) EPDL97 the evaluated photon data library,’97 version, Report UCRL-50400 6(4) parts A and B Livermore, CA: Lawrence Livermore National Laboratory.
Ribberfors R (1983) X-ray incoherent scattering total cross sections and energy-absorption cross sections by means of simple calculation routines Phys. Rev. A 27 3061–70.
Baró J, Roteta M, Fernández-Varea JM and Salvat F (1994) Analytical cross sections for Monte Carlo simulation of photon transport Radiat. Phys. Chem. 44 531–52.
Berger MJ (1963) Monte Carlo calculation of the penetration and diffusion of fast charged particles Methods in Computational Physics 1 eds.Alder BFernbach S and Rotenberg M (Academic Press, New York) pp. 135–215.
Reimer L and Krefting ER (1976) The effect of scattering models on the results of Monte Carlo calculations National Bureau of Standards Special Publication 460(US Government Printing Office, Washington DC) 45–60.
Andreo P and Brahme A (1984) Restricted energy-loss straggling and multiple scattering of electrons in mixed Monte Carlo procedures Rad. Res. 100 16–29.
Seltzer SM and Berger MJ (1985) Bremsstrahlung spectra from electron interactions with screened atomic nuclei and orbital electrons Nucl. Instrum. Meth.B 12 95–134.
Seltzer SM and Berger MJ (1986) Bremsstrahlung energy spectra from electrons with kinetic energy 1 keV–10 GeV incident on screened nuclei and orbital electrons of neutral atoms with Z=1–100 At Nucl. Data Tables 35 345–418.
National Nuclear Data Center (NNDC), Brookhaven National Laboratory NUDAT2.0. Electronic Version available online at NNDC: http://www.nndc.bnl.gov/nudat2/, 2005.
Chesta MA, Plievelic TS and Mainardi RT (1998) Characteristic X-rays Induced by Electrons and Positrons from b-emitting Radioisotopes, Nucl. Inst. & Methods in Phys. Res. B, 145(3) 459-68.
Chesta MA, Plievelic TS and Mainardi RT (2002) A Multi-propose X-Ray Source of Tunnable Energy, Nucl. Inst. & Methods in Phys. Res. B, 187 259-63.
Johns H E and Cunningham J R (1983) The physics of radiology Fourth edition Charles C Thomas Publisher Illinois 796 p.
Wang R and Li XA (2002) Dose characterization in the near-source region for two high dose rate brachytherapy sources Med. Phys. 29(8)1678–86.
Pérez-Calatayud J, Granero D and Ballester F (2004) Phantom size in brachytherapy source dosimetric studies Med. Phys. 31(7) 2075-81.