title: Experimental validation of Monte Carlo dose calculations about a high-intensity Ir-192 source for pulsed dose-rate brachytherapy.
abstract: Despite widespread use of high-intensity Ir-192 remotely afterloaded sources, no published measured or calculated dose-rate tables for currently used source designs are available. For a pulsed dose-rate Ir-192 source, both transverse axis (0.5-10 cm) and two-dimensional polar dose-rate profiles (1.5, 3, and 5 cm) were measured with thermoluminescent dosimetry in a solid water phantom. Dose rates were normalized to measured air-kerma strength, and the source geometry was verified by pinhole autoradiography and transmission radiography. At each measurement point, dose rates were calculated by a Monte Carlo photon transport (MCPT) code, which realistically modeled the experimental phantom, source, and detector geometry. Agreement between MCPT absolute dose-rate calculations and measurements averaged 3% and was less than 5%, demonstrating that Monte Carlo simulation is an accurate and powerful tool for two-dimensional dosimetric characterization of high activity Ir-192 sources.
authors.affiliation: Radiation Oncology Center, Mallinckrodt Institute of Radiology, Washington University School of Medicine, St. Louis, Missouri 63110, USA.
authors.forename: R K
authors.initials: RK
authors.lastname: Valicenti
authors.forename: A S
authors.initials: AS
authors.lastname: Kirov
authors.forename: A S
authors.initials: AS
authors.lastname: Meigooni
authors.forename: V
authors.initials: V
authors.lastname: Mishra
authors.forename: R K
authors.initials: RK
authors.lastname: Das
authors.forename: J F
authors.initials: JF
authors.lastname: Williamson
mesh_terms: D001918:Brachytherapy / Q000295:instrumentation / Q000379:methods*; D006801:Humans; D007496:Iridium Radioisotopes / Q000627:therapeutic use*; D008163:Luminescent Measurements; D008433:Mathematics; D008961:Models, Structural; D009010:Monte Carlo Method; D011879:Radiotherapy Dosage; D015203:Reproducibility of Results
chemical_list: D007496:Iridium Radioisotopes