title: Double-film technique for the determination of the homogeneity of line sources.
abstract: A new technique is presented for determining the homogeneity of the linear activity. The method uses two x-ray films that are firmly pressed against opposing sides of a needle containing a radioactive line source. The homogeneity of the linear activity of 68 iridium-192 wires has been measured. About 80% of the measured linear activities showed deviations of no more than 5% from the mean; about 20% of the measured linear activities showed deviations of 5%-10% from the mean. Individual wires may contain deviations of 5% or more extended over several centimeters, which causes the dose in the prescription point to deviate 5% from the desired value. Four wires (8%) were rejected for this reason.
authors: Radiotherapy Institute Limburg (RTIL), Heerlen, The Netherlands.
authors: J P
authors: JP
authors: Cuypers
authors: R J
authors: RJ
authors: de Vos
mesh_terms: D055592:Biophysical Phenomena; D001703:Biophysics; D001918:Brachytherapy; D005373:Film Dosimetry / Q000295:instrumentation / Q000379:methods*; D006801:Humans; D007496:Iridium Radioisotopes / Q000627:therapeutic use; D008962:Models, Theoretical; D015203:Reproducibility of Results; D013679:Technology, Radiologic
chemical_list: D007496:Iridium Radioisotopes