title: Evaluating the effect of various intracavitary applicators on dosimetric parameters of (192)Ir, (137)Cs, and (60)Co sources.
abstract: The purpose of this research is to study the effect of various applicator compositions on dosimetric parameters and dose distribution of (192)Ir, (137)Cs, and (60)Co sources, using Monte Carlo simulation techniques. To study the effect of applicators on source dosimetry, the dose rate constant, and radial dose function and isodose curves for the above noted sources were calculated in the presence and absence of plastic, titanium, and a stainless steel applicators. The effects of the applicators on the dosimetric parameters and isodose curves of these sources were dependent of the source type and materials of the applicator. The (192)Ir source with the stainless steel applicator has the maximum difference of dose rate (4.2 %) relative to the without applicator case. The (60)Co source with plastic applicator has the minimum dose variation. Moreover, this effect is higher for lower energy sources. Ignoring the effect of applicator composition and geometry on dose distribution may cause discrepancies in treatment planning. Plastic applicators have the least radiation attenuation compared to the other applicators, therefore, they are recommended for use in brachytherapy. A table of correction factors has been introduced for different sources and applicators with different materials for the clinical applications.
authors.affiliation: Medical Physics Research Center, Mashhad University of Medical Sciences, Mashhad, Iran.
authors.forename: Mahdi
authors.initials: M
authors.lastname: Ghorbani
authors.affiliation: Physics Group, Faculty of Basic Sciences, Hakim Sabzevari University, P.O. Box: 397, Sabzevar, Iran. hashempoor.ma@gmail.com.
authors.forename: Marjan
authors.initials: M
authors.lastname: Hashempour
authors.affiliation: Physics Group, Faculty of Basic Sciences, Hakim Sabzevari University, P.O. Box: 397, Sabzevar, Iran.
authors.forename: Mona
authors.initials: M
authors.lastname: Azizi
authors.affiliation: Comprehensive Cancer Centers of Nevada, Las Vegas, NV, USA.
authors.forename: Ali S
authors.initials: AS
authors.lastname: Meigooni
mesh_terms: D001918:Brachytherapy; D002588:Cesium Radioisotopes / Q000737:chemistry*; D003037:Cobalt Radioisotopes / Q000737:chemistry*; D003198:Computer Simulation; D004307:Dose-Response Relationship, Radiation; D007496:Iridium Radioisotopes / Q000737:chemistry*; D007700:Kinetics; D009010:Monte Carlo Method; D011874:Radiometry / Q000379:methods*; D014025:Titanium / Q000737:chemistry
chemical_list: D002588:Cesium Radioisotopes; D003037:Cobalt Radioisotopes; D007496:Iridium Radioisotopes; D014025:Titanium
keywords: Applicator; Brachytherapy; Dose distribution; Dosimetric parameters; Monte Carlo simulation