A feasibility study of Fricke dosimetry as an absorbed dose to water standard for 192Ir HDR sources

PLoS One. 2014 Dec 18;9(12):e115155. doi: 10.1371/journal.pone.0115155. eCollection 2014.

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.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Absorption, Radiation
  • Algorithms
  • Brachytherapy / methods
  • Brachytherapy / standards*
  • Feasibility Studies
  • Ferrous Compounds / radiation effects*
  • Iridium Radioisotopes / therapeutic use*
  • Radiometry / methods*
  • Radiotherapy Dosage / standards
  • Solutions / radiation effects*
  • Water / chemistry

Substances

  • Ferrous Compounds
  • Fricke solution
  • Iridium Radioisotopes
  • Solutions
  • Water

Grants and funding

This work was supported by Fundação de Amparo à Pesquisa do Estado do Rio de Janeiro (http://www.faperj.br/) - (CS, CEA), Conselho Nacional de Desenvolvimento Científico e Tecnológico (http://www.cnpq.br/) - (MGD, CEA), and Fundação de Amparo à Pesquisa do Estado de São Paulo (http://www.fapesp.br/) - (MAB). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.