Comprehensive Monte Carlo calculations of AAPM Task Group Report No. 43 dosimetry parameters for the Model 3500 I-Plant 125I brachytherapy source.
The Model 3500 I-Plant 125I brachytherapy source, produced by Implant Sciences Corporation, is created through a novel technique which utilizes ion implantation of 124Xe into a ceramic matrix followed by neutron activation of the substrate. Clinical dosimetry parameters were calculated using MCNP. For data processing, a 0.376 cm active length was used for the geometry function. The 2-D anisotropy function, F(r, 0), exhibited less anisotropy than the Amersham Health Model 6711 source, and decreased as radial distance, r, increased. The anisotropy constant, phi an, was 0.933; dose rate constant, lambda, was 1.017 +/- 0.005 cGy/h/U; and radial dose function, g(r), for r = (0.1, 0.2, 0.5, 2, 5, 10 cm) was 0.990, 1.014, 1.030, 0.872, 0.448, and 0.114, respectively. In general, there was good agreement with experimental results recently obtained by others using thermoluminescent dosimeters.
Department of Radiation Oncology, Tufts University School of Medicine, New England Medical Center #246, 750 Washington Street, Boston, MA 02111, USA. mrivard@lifespan.org
Mark J
MJ
Rivard
D001918:Brachytherapy / Q000295:instrumentation* / Q000706:statistics & numerical data; D003198:Computer Simulation; D006801:Humans; D007457:Iodine Radioisotopes / Q000627:therapeutic use*; D009010:Monte Carlo Method; D017785:Photons; D011880:Radiotherapy Planning, Computer-Assisted
D007457:Iodine Radioisotopes