title: Monte Carlo dosimetric study of the medium dose rate CSM40 source.
abstract: The (137)Cs medium dose rate (MDR) CSM40 source model (Eckert & Ziegler BEBIG, Germany) is in clinical use but no dosimetric dataset has been published. This study aims to obtain dosimetric data for the CSM40 source for its use in clinical practice as required by the American Association of Physicists in Medicine (AAPM) and the European Society for Radiotherapy and Oncology (ESTRO). Penelope2008 and Geant4 Monte Carlo codes were used to characterize this source dosimetrically. It was located in an unbounded water phantom with composition and mass density as recommended by AAPM and ESTRO. Due to the low photon energies of (137)Cs, absorbed dose was approximated by collisional kerma. Additional simulations were performed to obtain the air-kerma strength, sK. Mass-energy absorption coefficients in water and air were consistently derived and used to calculate collisional kerma. Results performed with both radiation transport codes showed agreement typically within 0.05%. Dose rate constant, radial dose function and anisotropy function are provided for the CSM40 and compared with published data for other commercially available (137)Cs sources. An uncertainty analysis has been performed. The data provided by this study can be used as input data and verification in the treatment planning systems.
authors.affiliation: Department of Atomic, Molecular and Nuclear Physics, University of Valencia, E-46100 Burjassot, Spain; IFIC (UV-CSIC), Paterna, Spain. Electronic address: Javier.vijande@uv.es.
authors.forename: J
authors.initials: J
authors.lastname: Vijande
authors.forename: D
authors.initials: D
authors.lastname: Granero
authors.forename: J
authors.initials: J
authors.lastname: Perez-Calatayud
authors.forename: F
authors.initials: F
authors.lastname: Ballester
mesh_terms: D016880:Anisotropy; D002588:Cesium Radioisotopes / Q000032:analysis* / Q000627:therapeutic use; D006801:Humans; D009010:Monte Carlo Method; D019047:Phantoms, Imaging; D011874:Radiometry / Q000706:statistics & numerical data*; D011879:Radiotherapy Dosage; D011880:Radiotherapy Planning, Computer-Assisted / Q000706:statistics & numerical data*; D014867:Water
chemical_list: D002588:Cesium Radioisotopes; D014867:Water
keywords: Brachytherapy; Cs-137 seed; Monte Carlo; TG-43 based dosimetry