title: A feasibility study of Fricke dosimetry as an absorbed dose to water standard for 192Ir HDR sources.
abstract: High dose rate brachytherapy (HDR) using 192Ir sources is well accepted as an important treatment option and thus requires an accurate dosimetry standard. However, a dosimetry standard for the direct measurement of the absolute dose to water for this particular source type is currently not available. An improved standard for the absorbed dose to water based on Fricke dosimetry of HDR 192Ir brachytherapy sources is presented in this study. The main goal of this paper is to demonstrate the potential usefulness of the Fricke dosimetry technique for the standardization of the quantity absorbed dose to water for 192Ir sources. A molded, double-walled, spherical vessel for water containing the Fricke solution was constructed based on the Fricke system. The authors measured the absorbed dose to water and compared it with the doses calculated using the AAPM TG-43 report. The overall combined uncertainty associated with the measurements using Fricke dosimetry was 1.4% for k = 1, which is better than the uncertainties reported in previous studies. These results are promising; hence, the use of Fricke dosimetry to measure the absorbed dose to water as a standard for HDR 192Ir may be possible in the future.
authors.affiliation: Laboratório de Ciências Radiológicas, LCR-IBRAG-UERJ, Rio de Janeiro, RJ, Brazil.
authors.forename: Carlos Eduardo
authors.initials: CE
authors.lastname: deAlmeida
authors.affiliation: Laboratório de Ciências Radiológicas, LCR-IBRAG-UERJ, Rio de Janeiro, RJ, Brazil.
authors.forename: Ricardo
authors.initials: R
authors.lastname: Ochoa
authors.affiliation: Laboratório de Ciências Radiológicas, LCR-IBRAG-UERJ, Rio de Janeiro, RJ, Brazil.
authors.forename: Marilene Coelho de
authors.initials: MC
authors.lastname: Lima
authors.affiliation: Laboratório de Ciências Radiológicas, LCR-IBRAG-UERJ, Rio de Janeiro, RJ, Brazil.
authors.forename: Mariano Gazineu
authors.initials: MG
authors.lastname: David
authors.affiliation: Laboratório de Ciências Radiológicas, LCR-IBRAG-UERJ, Rio de Janeiro, RJ, Brazil.
authors.forename: Evandro Jesus
authors.initials: EJ
authors.lastname: Pires
authors.affiliation: Laboratório Nacional de Metrologia das Radiações Ionizantes, LNMRI-IRD, Rio de Janeiro, RJ, Brazil.
authors.forename: José Guilherme
authors.initials: JG
authors.lastname: Peixoto
authors.affiliation: Laboratório de Ciências Radiológicas, LCR-IBRAG-UERJ, Rio de Janeiro, RJ, Brazil.
authors.forename: Camila
authors.initials: C
authors.lastname: Salata
authors.affiliation: Instituto de Física Gleb Wataghin, Universidade Estadual de Campinas, Campinas, SP, Brazil.
authors.forename: Mario Antônio
authors.initials: MA
authors.lastname: Bernal
mesh_terms: D065638:Absorption, Radiation; D000465:Algorithms; D001918:Brachytherapy / Q000379:methods / Q000592:standards*; D005240:Feasibility Studies; D005296:Ferrous Compounds / Q000528:radiation effects*; D007496:Iridium Radioisotopes / Q000627:therapeutic use*; D011874:Radiometry / Q000379:methods*; D011879:Radiotherapy Dosage / Q000592:standards; D012996:Solutions / Q000528:radiation effects*; D014867:Water / Q000737:chemistry
chemical_list: D005296:Ferrous Compounds; C075364:Fricke solution; D007496:Iridium Radioisotopes; D012996:Solutions; D014867:Water