title: Dose distributions of an ¹⁹²Ir brachytherapy source in different media.
abstract: This study used MCNPX code to investigate the brachytherapy (192)Ir dose distributions in water, bone, and lung tissue and performed radiophotoluminescent glass dosimeter measurements to verify the obtained MCNPX results. The results showed that the dose-rate constant, radial dose function, and anisotropy function in water were highly consistent with data in the literature. However, the lung dose near the source would be overestimated by up to 12%, if the lung tissue is assumed to be water, and, hence, if a tumor is located in the lung, the tumor dose will be overestimated, if the material density is not taken into consideration. In contrast, the lung dose far from the source would be underestimated by up to 30%. Radial dose functions were found to depend not only on the phantom size but also on the material density. The phantom size affects the radial dose function in bone more than those in the other tissues. On the other hand, the anisotropy function in lung tissue was not dependent on the radial distance. Our simulation results could represent valid clinical reference data and be used to improve the accuracy of the doses delivered during brachytherapy applied to patients with lung cancer.
authors.affiliation: Institute of Nuclear Engineering and Science, National Tsing Hua University, Hsinchu 300, Taiwan.
authors.forename: C H
authors.initials: CH
authors.lastname: Wu
authors.affiliation: School of Medical Laboratory Science and Biotechnology, College of Medical Science and Technology, Taipei Medical University, Taipei 110, Taiwan.
authors.forename: Y J
authors.initials: YJ
authors.lastname: Liao
authors.affiliation: Institute of Nuclear Engineering and Science, National Tsing Hua University, Hsinchu 300, Taiwan.
authors.forename: Y W Hsueh
authors.initials: YW
authors.lastname: Liu
authors.affiliation: School of Medicine, Tzu Chi University, Hualian 970, Taiwan ; Department of Radiation Oncology, Buddhist Dalin Tzu Chi General Hospital, Chiayi 622, Taiwan.
authors.forename: S K
authors.initials: SK
authors.lastname: Hung
authors.affiliation: School of Medicine, Tzu Chi University, Hualian 970, Taiwan ; Department of Radiation Oncology, Buddhist Dalin Tzu Chi General Hospital, Chiayi 622, Taiwan.
authors.forename: M S
authors.initials: MS
authors.lastname: Lee
authors.affiliation: Department of Biomedical Imaging and Radiological Sciences, National Yang-Ming University, Taipei 112, Taiwan ; Biophotonics and Molecular Imaging Research Center, National Yang-Ming University, Taipei 112, Taiwan.
authors.forename: S M
authors.initials: SM
authors.lastname: Hsu
mesh_terms: D001918:Brachytherapy / Q000379:methods*; D006801:Humans; D007496:Iridium Radioisotopes / Q000627:therapeutic use*; D009010:Monte Carlo Method; D019047:Phantoms, Imaging; D011874:Radiometry / Q000379:methods; D011879:Radiotherapy Dosage; D014867:Water / Q000737:chemistry
chemical_list: D007496:Iridium Radioisotopes; D014867:Water