title: Alanine/EPR dosimetry in brachytherapy.
abstract: The paper reports the experimental procedure adopted to determine the absorbed dose rate in water per reference air kerma rate, D(Kr), (d, theta), along the transverse bisector axis of a 137Cs brachytherapy source. The dose rate measurements have been carried out at difference distances, d, from the source using alanine dosemeters in a water phantom. The reference air kerma rate, Kr, was determined adopting a 'direct procedure' that uses a spherical ionization chamber in air. The dose rate constant of the source examined was D(Kr) (1, pi/2) = 0.99 +/- 0.03 cGy h(-1) (microGy h(-1))(-1). The values of the radial dose function along the transverse axis, g(d), determined with an uncertainty of 3.4% (1sigma), were found to be in good agreement with the results reported in the literature. The uncertainty in dose rate value has been estimated as 2.8% (1sigma) for distances from the source up to 7 cm. Kr has been determined with 1.2% (1sigma) uncertainty. So D(r) (d, pi/2) values were determined with 3% (1sigma) uncertainty.
authors.affiliation: Physics Laboratory, Istituto Superiore di Sanità, Rome, Italy. deangelis@axiss.iss.infn.it
authors.forename: C
authors.initials: C
authors.lastname: De Angelis
authors.forename: S
authors.initials: S
authors.lastname: Onori
authors.forename: E
authors.initials: E
authors.lastname: Petetti
authors.forename: A
authors.initials: A
authors.lastname: Piermattei
authors.forename: L
authors.initials: L
authors.lastname: Azario
mesh_terms: D000409:Alanine; D055592:Biophysical Phenomena; D001703:Biophysics; D001918:Brachytherapy; D002588:Cesium Radioisotopes / Q000627:therapeutic use; D004578:Electron Spin Resonance Spectroscopy; D005069:Evaluation Studies as Topic; D006801:Humans; D019047:Phantoms, Imaging; D011874:Radiometry / Q000295:instrumentation / Q000379:methods* / Q000706:statistics & numerical data; D011879:Radiotherapy Dosage; D014867:Water
chemical_list: D002588:Cesium Radioisotopes; D014867:Water; D000409:Alanine