title: The presence of iodinated contrast agents amplifies DNA radiation damage in computed tomography.
abstract: The purpose of this study was to determine the influence of iodinated contrast agents on the formation of DNA double-strand breaks in vitro in lymphocytes and to verify these results in patients undergoing diagnostic computed tomography examinations. Blood samples were irradiated in vitro in the presence of iodinated X-ray contrast agent. Controls were irradiated without contrast agent. Fourteen patients were investigated using contrast-enhanced computed tomography (CT), and 14 other patients with unenhanced CT. Blood samples were taken prior to and 5 min and 1, 2 and 24 h after the CT examination. In these blood samples the average number of γH2Ax-foci per lymphocyte was enumerated by fluorescence microscopy. Statistical differences between foci numbers developed in the presence and absence of contrast agent were tested using an independent sample t-test. In vitro foci numbers after irradiation were significantly higher when contrast agent was present during irradiation. In vivo, γH2Ax-foci levels were 58% higher in patients undergoing contrast-enhanced CT compared with those undergoing unenhanced CT. In the presence of iodinated contrast agents DNA, damage is increased and the radiation dose is not the only factor affecting the amount of DNA damage. Individual patient characteristics and biological dosimetry applications, e.g. the analysis of γH2Ax-foci, have to be considered.
authors.affiliation: Department of Diagnostic Radiology, Philipps University, Marburg, Germany.
authors.forename: Caroline
authors.initials: C
authors.lastname: Pathe
authors.forename: Katharina
authors.initials: K
authors.lastname: Eble
authors.forename: Daniel
authors.initials: D
authors.lastname: Schmitz-Beuting
authors.forename: Boris
authors.initials: B
authors.lastname: Keil
authors.forename: Bjoern
authors.initials: B
authors.lastname: Kaestner
authors.forename: Maximilian
authors.initials: M
authors.lastname: Voelker
authors.forename: Beate
authors.initials: B
authors.lastname: Kleb
authors.forename: Klaus J
authors.initials: KJ
authors.lastname: Klose
authors.forename: Johannes T
authors.initials: JT
authors.lastname: Heverhagen
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003287:Contrast Media / Q000009:adverse effects* / Q000737:chemistry; D053903:DNA Breaks, Double-Stranded; D005260:Female; D006657:Histones / Q000737:chemistry; D006801:Humans; D007455:Iodine / Q000009:adverse effects* / Q000737:chemistry; D008214:Lymphocytes / Q000187:drug effects / Q000528:radiation effects; D008297:Male; D008856:Microscopy, Fluorescence; D008875:Middle Aged; D014057:Tomography, X-Ray Computed / Q000009:adverse effects*
chemical_list: D003287:Contrast Media; C468783:H2AX protein, human; D006657:Histones; D007455:Iodine