Effect of tissue composition on dose distribution in brachytherapy with various photon emitting sources.

Publisher: Termedia Pub. House Country of Publication: Poland NLM ID: 101506276 Publication Model: Print-Electronic Cited Medium: Print ISSN: 1689-832X (Print) Linking ISSN: 20812841 NLM ISO Abbreviation: J Contemp Brachytherapy Subsets: PubMed not MEDLINE

Original Publication: Poznań : Termedia Pub. House

Purpose: The aim of this study is to compare the dose in various soft tissues in brachytherapy with photon emitting sources.
Material and Methods: (103)Pd, (125)I, (169)Yb, (192)Ir brachytherapy sources were simulated with MCNPX Monte Carlo code, and their dose rate constant and radial dose function were compared with the published data. A spherical phantom with 50 cm radius was simulated and the dose at various radial distances in adipose tissue, breast tissue, 4-component soft tissue, brain (grey/white matter), muscle (skeletal), lung tissue, blood (whole), 9-component soft tissue, and water were calculated. The absolute dose and relative dose difference with respect to 9-component soft tissue was obtained for various materials, sources, and distances.
Results: There was good agreement between the dosimetric parameters of the sources and the published data. Adipose tissue, breast tissue, 4-component soft tissue, and water showed the greatest difference in dose relative to the dose to the 9-component soft tissue. The other soft tissues showed lower dose differences. The dose difference was also higher for (103)Pd source than for (125)I, (169)Yb, and (192)Ir sources. Furthermore, greater distances from the source had higher relative dose differences and the effect can be justified due to the change in photon spectrum (softening or hardening) as photons traverse the phantom material.
Conclusions: The ignorance of soft tissue characteristics (density, composition, etc.) by treatment planning systems incorporates a significant error in dose delivery to the patient in brachytherapy with photon sources. The error depends on the type of soft tissue, brachytherapy source, as well as the distance from the source.

J Contemp Brachytherapy. 2011 Dec;3(4):199-208. (PMID: 23346129)
Appl Radiat Isot. 2001 Dec;55(6):775-82. (PMID: 11761099)
Med Phys. 2011 Feb;38(2):782-801. (PMID: 21452716)
Med Phys. 2008 Oct;35(10):4708-23. (PMID: 18975716)
PLoS One. 2012;7(9):e44528. (PMID: 22957078)
J Cancer Res Ther. 2010 Jan-Mar;6(1):54-7. (PMID: 20479548)
Phys Med Biol. 2003 Nov 7;48(21):R107-64. (PMID: 14653555)
Med Phys. 2012 Apr;39(4):1769-78. (PMID: 22482600)
Med Phys. 2010 Aug;37(8):4038-45. (PMID: 20879565)
Med Phys. 2009 Jun;36(6):2136-53. (PMID: 19610303)
Med Phys. 2010 Mar;37(3):1129-36. (PMID: 20384248)
Med Phys. 2012 Oct;39(10):6208-36. (PMID: 23039658)
Drug Discov Today. 2010 Oct;15(19-20):842-50. (PMID: 20727417)
Phys Med Biol. 2012 Jun 7;57(11):3585-96. (PMID: 22588230)
Phys Med Biol. 2012 Mar 7;57(5):1173-90. (PMID: 22330195)
Australas Phys Eng Sci Med. 2012 Jun;35(2):177-85. (PMID: 22700179)
Med Phys. 2008 Sep;35(9):4228-41. (PMID: 18841873)
Med Phys. 2004 Mar;31(3):633-74. (PMID: 15070264)
Med Phys. 2006 Jun;33(6):1729-37. (PMID: 16872080)
Radiat Prot Dosimetry. 2011 Sep;147(1-2):287-90. (PMID: 21831865)
J Med Phys. 2010 Jan;35(1):15-22. (PMID: 20177566)
Med Phys. 2009 Jun;36(6):2228-35. (PMID: 19610312)
J Contemp Brachytherapy. 2012 Jun;4(2):81-91. (PMID: 23349649)
Med Phys. 2007 Jun;34(6):1999-2006. (PMID: 17654903)
Med Phys. 1994 May;21(5):631-41. (PMID: 7935197)
J Contemp Brachytherapy. 2012 Mar;4(1):52-9. (PMID: 23346140)
Med Phys. 2007 Jun;34(6):2187-205. (PMID: 17654921)
Med Phys. 2001 Dec;28(12):2576-85. (PMID: 11797963)

Keywords: ICRU; brachytherapy; photon emitting sources; relative dose; soft tissue

Date Created: 20140503 Date Completed: 20140505 Latest Revision: 20220408

20250114

PMC4003431

10.5114/jcb.2014.42024

24790623