title: Monte Carlo dosimetry of a new (90)Y brachytherapy source.
abstract: OBJECTIVE
  In this study, we attempted to obtain full dosimetric data for a new (90)Y brachytherapy source developed by the College of Chemistry (Sichuan University) for use in high-dose-rate after-loading systems.
  
  
  METHODS
  The dosimetric data for this new source were used as required by the dose calculation formalisms proposed by the AAPM Task Group 60 and Task Group 149. The active core length of the new (90)Y source was increased to 4.7 mm compared to the value of 2.5 mm for the old (90)Sr/(90)Y source. The Monte Carlo simulation toolkit Geant4 was used to calculate these parameters. The source was located in a 30-cm-radius theoretical sphere water phantom.
  
  
  RESULTS
  The dosimetric data included the reference absorbed dose rate, the radial dose function in the range of 1.0 to 8.0 mm in the longitudinal axis, and the anisotropy function with a θ in the range of 0° to 90° at 5° intervals and an r in the range of 1.0 to 8.0 mm in 0.2-mm intervals. The reference absorbed dose rate for the new (90)Y source was determined to be equal to 1.6608 ± 0.0008 cGy s(-1) mCi(-1), compared to the values of 0.9063 ± 0.0005 cGy s(-1) mCi(-1) that were calculated for the old (90)Sr/(90)Y source. A polynomial function was also obtained for the radial dose function by curve fitting.
  
  
  CONCLUSIONS
  Dosimetric data are provided for the new (90)Y brachytherapy source. These data are meant to be used commercially in after-loading system.
authors.affiliation: Key Laboratory of Radiation Physics and Technology, Ministry of Education and Institute of Nuclear Science and Technology, Sichuan University.
authors.forename: Wu
authors.initials: W
authors.lastname: Junxiang
authors.affiliation: Key Laboratory of Radiation Physics and Technology, Ministry of Education and Institute of Nuclear Science and Technology, Sichuan University.
authors.forename: You
authors.initials: Y
authors.lastname: Shihu
authors.affiliation: Key Laboratory of Radiation Physics and Technology, Ministry of Education and Institute of Nuclear Science and Technology, Sichuan University.
authors.forename: Huang
authors.initials: H
authors.lastname: Jing
authors.affiliation: Key Laboratory of Radiation Physics and Technology, Ministry of Education and Institute of Nuclear Science and Technology, Sichuan University.
authors.forename: Long
authors.initials: L
authors.lastname: Fengxiang
authors.affiliation: College of Chemistry, Sichuan University, Chengdu Sichuan 610064, China.
authors.forename: Wang
authors.initials: W
authors.lastname: Chengkai
authors.affiliation: Key Laboratory of Radiation Physics and Technology, Ministry of Education and Institute of Nuclear Science and Technology, Sichuan University.
authors.forename: Wu
authors.initials: W
authors.lastname: Zhangwen
authors.affiliation: Key Laboratory of Radiation Physics and Technology, Ministry of Education and Institute of Nuclear Science and Technology, Sichuan University.
authors.forename: Hou
authors.initials: H
authors.lastname: Qing
authors.affiliation: Key Laboratory of Radiation Physics and Technology, Ministry of Education and Institute of Nuclear Science and Technology, Sichuan University.
authors.forename: Gou
authors.initials: G
authors.lastname: Chengjun
keywords: 90Y source; Geant4; Monte Carlo; brachytherapy; dosimetry