Age-dependent differences in DNA damage after in vitro CT exposure

Abstract

Purpose: Age dependent radiation sensitivity for DNA damage after in vitro blood exposure by computer tomography (CT) was investigated.

Materials and methods: Radiation biomarkers (dicentrics and gammaH2AX) in blood samples of newborns, children under five years and adults after sham exposure (0 mGy), low-dose (41 mGy) and high-dose (978 mGy) in vitro CT exposure were analyzed.

Results: Significantly higher levels of dicentric induction were found for the single and combined newborns/children group compared to adults, by a factor of 1.48 (95% CI 1.30–1.68), after exposure to 978 mGy. Although a significant dose response for damage induction and dose-dependent repair was found, the gammaH2AX assay did not show an age-dependent increase in DNA damage in newborns/children compared to adults. This was the case for the gammaH2AX levels after repair time intervals of 30 minutes and 24 hours, after correcting for the underlying background damage. For the low dose of 41 mGy, the power of the dicentric assay was also not sufficient to detect an age-dependent effect in the sample size investigated.

Conclusion: A 1.5-fold increased level of dicentric aberrations is detected in newborns and children under five years after 1 Gy radiation exposure.

Keywords:

• DNA damage
• computer tomography CT
• dicentric chromosome assay
• gammaH2AX assay
• children

Acknowledgements

Thanks to all children and BfS staff, who supported the study with their blood.

Disclosure statement

The authors declare that they have no competing interests.

Health and safety

All mandatory laboratory health and safety procedures have been complied with in the course of conducting any experimental work.

Additional information

Funding

The study was financially supported by EPI-CT EU-Grant [FP7-EURATOM-FISSION 97571].

Notes on contributors

Maria Gomolka

Maria Gomolka, PhD, is a biologist and senior scientist in the working group biological radiation effects, biological dosimetry, Federal Office for Radiation Protection, Oberschleissheim, Germany.

Ursula Oestreicher

Ursula Oestreicher, Dipl. Biol., senior scientist, Federal Office for Radiation Protection (BfS), Unit: Biological Radiation Effects, Biological Dosimetry, Neuherberg, Germany.

Ute Rößler

Ute Rößler, PhD, biologist, working on topics of radiation effects and radiation sensitivity as a senior scientist at the Federal Office for Radiation Protection.

Daniel Samaga

Daniel Samaga was biomathematician at Bundesamt für Strahlenschutz and is currently working as a biomathematician at Helmholtz Zentrum Munich, Neuherberg, Germany.

David Endesfelder

Dr. David Endesfelder, is a biomathematician at Bundesamt für Strahlenschutz, Neuherberg, Germany and previously did a PostDoc as a biomathematician at Helmholtz Zentrum Munich, Neuherberg, Germany.

Peter Lang

Peter Lang, Dipl. Phys., Medical physicist at University Hospital, LMU Munich, Department of Radiation Oncology, Munich, Germany.

Klement Neumaier

Klement Neumaier, is a medical engineer, specialist in thermoluminescent dosimetry at University Hospital, LMU Munich, Department of Radiation Oncology, Munich, Germany.

Claus Belka

Prof. Dr. med. Claus Belka, is Chair at University Hospital, LMU Munich, Department of Radiation Oncology, Munich, Germany.

Markus Niemeyer

Markus Niemeyer, MD, Senior Physician in the Obs&Gyn-Department of the ‘Klinikum Rechts der Isar’ Technical University of Munich, Germany.

Marion Kiechle

Prof. Dr. med. Marion Kiechle, is chair of the Obs&Gyn-Department of the ‘Klinikum Rechts der Isar’ Technical University of Munich, Germany.

Uwe Hasbargen

Uwe Hasbargen is chief of perinatology at the Perinatal Center, LMU Munich, Germany.

Christoph Hübener

Christoph Hübener is a consultant in obstetrics and gynaecology at the University Hospital, LMU Munich, Germany.

Hans-Joachim Kirlum

Hans-Joachim Kirlum, MD, is Head of the “Kinderchirurgie in the Au”, München, Germany.

Ulrike Kulka

Ulrike Kulka, PhD, is a biologist and head of the working group biological radiation effects, biological dosimetry, Federal Office for Radiation Protection, Oberschleissheim, Germany.

Albert Rosenberger

Albert Rosenberger, PhD, is an epidemiologist and research associate, University Medical Centre, Georg-August University of Göttingen, Göttingen, Germany.

Linda Walsh

Linda Walsh, PhD, DSc, is a physicist, radiation epidemiologist and freelance consultant, affiliated with the Medical Physics group, University of Zurich, Switzerland.

Sarah Baatout

Prof. Sarah Baatout is Head of Radiobiology Unit, Belgian Nuclear Research Centre, SCK-CEN, Mol, Belgium.

Ausrele Kesminiene

Ausrele Kesminiene is currently a senior visiting scientist, previously the Deputy Head of Environment and Radiation Section, at the International Agency for Research on Cancer of WHO in Lyon, France.

Carita Lindholm

Carita Lindholm, PhD, Inspector, Radiation Metrology Laboratory and Occupational Exposure, previously Senior Scientist, Radiation Biology Laboratory; Radiation and Nuclear Safety Authority, Helsinki, Finland.