title: Relative biological effectiveness of 25 and 10 kV X-rays for the induction of chromosomal aberrations in two human mammary epithelial cell lines.
abstract: Administration of ionizing radiation for diagnostic purposes can be associated with a risk for the induction of tumors. Therefore, particularly with regard to general screening programs, e.g. with mammography, cost-benefit considerations must be discussed including risk estimation depending upon the radiation quality administered. The present study was initiated to investigate the in vitro X-ray energy dependence for the induction of chromosomal aberrations in the two mammary epithelial cell lines, 184A1 and MCF-12A. The induced excess fragments, dicentric chromosomes and centric rings were analyzed and the relative biological effectiveness (RBE) was determined for 10 and 25 kV X-rays relative to 200 kV X-rays. The assumed energy dependence with higher values for 10 kV X-rays was confirmed for the excess fragments, with RBE(M) values of 1.92 +/- 0.26 and 1.40 +/- 0.12 for 10 kV X-rays and 1.17 +/- 0.12 and 0.97 +/- 0.10 for 25 kV photons determined for cell lines 184A1 and MCF-12A, respectively. Meaningful results for the induction of dicentric chromosomes and centric rings were obtained only for higher doses with RBE values of 1.31 +/- 0.21 and 1.70 +/- 0.29 for 184A1 and 1.08 +/- 0.08 and 1.43 +/- 0.12 for MCF-12A irradiated with 25 and 10 kV X-rays, respectively.
authors.affiliation: Institute of Radiation Physics, Forschungszentrum Dresden-Rossendorf, Dresden, Germany. E.Beyreuther@fzd.de
authors.forename: Elke
authors.initials: E
authors.lastname: Beyreuther
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Dörr
authors.forename: Anna
authors.initials: A
authors.lastname: Lehnert
authors.forename: Elisabeth
authors.initials: E
authors.lastname: Lessmann
authors.forename: Jörg
authors.initials: J
authors.lastname: Pawelke
mesh_terms: D000328:Adult; D002460:Cell Line; D002869:Chromosome Aberrations / Q000528:radiation effects*; D004307:Dose-Response Relationship, Radiation; D005260:Female; D006801:Humans; D042361:Mammary Glands, Human / Q000378:metabolism / Q000473:pathology* / Q000528:radiation effects*; D008677:Metaphase / Q000235:genetics / Q000528:radiation effects; D017785:Photons / Q000009:adverse effects; D012062:Relative Biological Effectiveness; D014965:X-Rays / Q000009:adverse effects