title: Leukocyte DNA damage after reduced and conventional absorbed radiation doses using 3rd generation dual-source CT technology.
abstract: OBJECTIVE
  Computed tomography (CT) scans are an important source of ionizing irradiation (IR) in medicine that can induce a variety of DNA damage in human tissues. With technological improvements CT scans at reduced absorbed doses became feasible presumably lowering genotoxic side effects.
  
  
  METHODS
  For measuring DNA damage we performed γH2AX foci microscopy in peripheral blood mononuclear cells (PBMC) after exposure to reduced and conventional absorbed radiation doses using 3rd generation dual-source CT (DSCT) technology.
  
  
  RESULTS
  CT scans performed at reduced absorbed doses of 3 mGy induced significant lower levels (p < 0.0001) of DNA damage (0.05 focus per cell ± 0.01 [mean ± standard error of mean]) at 5 min after IR compared to conventional absorbed doses of 15 mGy (0.30 focus per cell ± 0.03). With ongoing DNA repair background γH2AX foci levels (0.05 focus per cell) were approached at 24 h after CT with both protocols.
  
  
  CONCLUSIONS
  Our results provide evidence that reduced absorbed doses mediated by adjusted tube current in 3rd generation DSCT induce lower levels of DNA damage in PBMC compared to conventional absorbed doses suggesting a lower genotoxic risk for state-of-the-art tube current reduced CT protocols.
authors.affiliation: Department of Hematology and Oncology, Medical Faculty Mannheim of the University of Heidelberg, Theodor-Kutzer-Ufer 1-3, 68167 Mannheim, Germany.
authors.forename: Henning D
authors.initials: HD
authors.lastname: Popp
authors.affiliation: Institute of Clinical Radiology and Nuclear Medicine, Medical Faculty Mannheim of the University of Heidelberg, Theodor-Kutzer-Ufer 1-3, 68167 Mannheim, Germany.
authors.forename: Mathias
authors.initials: M
authors.lastname: Meyer
authors.affiliation: Department of Hematology and Oncology, Medical Faculty Mannheim of the University of Heidelberg, Theodor-Kutzer-Ufer 1-3, 68167 Mannheim, Germany.
authors.forename: Susanne
authors.initials: S
authors.lastname: Brendel
authors.affiliation: Department of Hematology and Oncology, Medical Faculty Mannheim of the University of Heidelberg, Theodor-Kutzer-Ufer 1-3, 68167 Mannheim, Germany.
authors.forename: Wiltrud
authors.initials: W
authors.lastname: Prinzhorn
authors.affiliation: Department of Hematology and Oncology, Medical Faculty Mannheim of the University of Heidelberg, Theodor-Kutzer-Ufer 1-3, 68167 Mannheim, Germany.
authors.forename: Nicole
authors.initials: N
authors.lastname: Naumann
authors.affiliation: Department of Statistical Analysis, Medical Faculty Mannheim of the University of Heidelberg, Ludolf-Krehl-Strasse 13-17, 68167 Mannheim, Germany.
authors.forename: Christel
authors.initials: C
authors.lastname: Weiss
authors.affiliation: Department of Hematology and Oncology, Medical Faculty Mannheim of the University of Heidelberg, Theodor-Kutzer-Ufer 1-3, 68167 Mannheim, Germany.
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Seifarth
authors.affiliation: Institute of Clinical Radiology and Nuclear Medicine, Medical Faculty Mannheim of the University of Heidelberg, Theodor-Kutzer-Ufer 1-3, 68167 Mannheim, Germany.
authors.forename: Stefan O
authors.initials: SO
authors.lastname: Schoenberg
authors.affiliation: Department of Hematology and Oncology, Medical Faculty Mannheim of the University of Heidelberg, Theodor-Kutzer-Ufer 1-3, 68167 Mannheim, Germany.
authors.forename: Wolf-K
authors.initials: WK
authors.lastname: Hofmann
authors.affiliation: Institute of Clinical Radiology and Nuclear Medicine, Medical Faculty Mannheim of the University of Heidelberg, Theodor-Kutzer-Ufer 1-3, 68167 Mannheim, Germany.
authors.forename: Thomas
authors.initials: T
authors.lastname: Henzler
authors.affiliation: Department of Hematology and Oncology, Medical Faculty Mannheim of the University of Heidelberg, Theodor-Kutzer-Ufer 1-3, 68167 Mannheim, Germany.
authors.forename: Alice
authors.initials: A
authors.lastname: Fabarius
keywords: 3rd generation dual-source CT; DNA double-strand breaks; X-rays; γH2AX foci