title: Experimental and Monte Carlo dosimetric characterization of a 1 cm (103)Pd brachytherapy source.
abstract: OBJECTIVE
  To determine the in-air azimuthal anisotropy and in-water dose distribution for the 1 cm length of a new elongated (103)Pd brachytherapy source through both experimental measurements and Monte Carlo (MC) simulations. Measured and MC-calculated dose distributions were used to determine the American Association of Physicists in Medicine Task Group No. 43 (TG-43) dosimetry parameters for this source.
  
  
  METHODS
  The in-air azimuthal anisotropy of the source was measured with a NaI scintillation detector and was simulated with the MCNP5 radiation transport code. Measured and MC results were normalized to their respective mean values and then compared. The source dose distribution was determined from measurements with LiF:Mg,Ti thermoluminescent dosimeter (TLD) microcubes and MC simulations. TG-43 dosimetry parameters for the source, including the dose-rate constant, Λ, two-dimensional anisotropy function, F(r, θ), and line-source radial dose function, gL(r), were determined from the TLD measurements and MC simulations.
  
  
  RESULTS
  NaI scintillation detector measurements and MC simulations of the in-air azimuthal anisotropy of the source showed that ≥95% of the normalized values for each source were within 1.2% of the mean value. TLD measurements and MC simulations of Λ, F(r, θ), and gL(r) agreed to within the associated uncertainties.
  
  
  CONCLUSIONS
  This new (103)Pd source exhibits a high level of azimuthal symmetry as indicated by the measured and MC-calculated results for the in-air azimuthal anisotropy. TG-43 dosimetry parameters for the source were determined through TLD measurements and MC simulations.
authors.affiliation: Department of Medical Physics, University of Wisconsin-Madison, UW Medical Radiation Research Center, Madison, WI. Electronic address: jlreed2@wisc.edu.
authors.forename: Joshua L
authors.initials: JL
authors.lastname: Reed
authors.affiliation: Department of Radiation Oncology, Tufts University School of Medicine, Boston, MA.
authors.forename: Mark J
authors.initials: MJ
authors.lastname: Rivard
authors.affiliation: Department of Medical Physics, University of Wisconsin-Madison, UW Medical Radiation Research Center, Madison, WI.
authors.forename: John A
authors.initials: JA
authors.lastname: Micka
authors.affiliation: Department of Medical Physics, University of Wisconsin-Madison, UW Medical Radiation Research Center, Madison, WI.
authors.forename: Wesley S
authors.initials: WS
authors.lastname: Culberson
authors.affiliation: Department of Medical Physics, University of Wisconsin-Madison, UW Medical Radiation Research Center, Madison, WI.
authors.forename: Larry A
authors.initials: LA
authors.lastname: DeWerd
mesh_terms: D016880:Anisotropy; D001918:Brachytherapy / Q000295:instrumentation / Q000379:methods*; D006801:Humans; D009010:Monte Carlo Method; D010165:Palladium / Q000627:therapeutic use*; D011868:Radioisotopes / Q000627:therapeutic use*; D011874:Radiometry / Q000379:methods; D013819:Thermoluminescent Dosimetry; D035501:Uncertainty
chemical_list: D011868:Radioisotopes; D010165:Palladium
keywords: (103)Pd; Brachytherapy; CS10; CivaString; Dosimetry characterization