EPI-CT: Epidemiological Study To Quantify Risk For Paediatric Computerized Tomography And To Optimize Doses

Isabelle THIERRY-CHEF, International Agency for Research on Cancer, France
CARDIS E. 2 , PEARCE M. 3 , BAATOUT S. 4 , HAUPTMANN M. 5 , MACCIA C. 6 , JAHNEN A. 7 , KAIJSER M. 8 , KESMINIENE A. 1

1 Section of Environment and Radiation, International Agency for Research on Cancer, Lyon, France
2 Radiation Programme, ISGlobal, Centre for Research in Environmental Epidemiology (CREAL), Barcelona, Spain
3 Institute of Health & Society, Newcastle University, Newcastle upon Tyne, United Kingdom
4 Radiobiology Unit, Belgian Nuclear Research Centre (SCK-CEN), Mol, Belgium
5 Bioinformatics and Statistics, The Netherlands Cancer Institute, Amsterdam, The Netherlands
6 Centre d’Assurance de qualité des Applications Technologiques dans le domaine de la Santé, Bourg-La-Reine, France
7 Luxembourg Institute of Science and Technology, Luxemburg, Luxembourg
8 Karolinska Institutet, Stockholm, Sweden

Purpose – The increasing worldwide use of paediatric computed tomography (CT) led to increasing concerns regarding the iatrogenic effects of ionizing radiation on children. Recent national studies on paediatric CT reported increased risks of childhood leukaemia and brain cancer. Uncertainties on the risk estimates remain as these studies often lack information on the medical history of the patients and exposure assessment was based on group-average approaches, rather than on individual data. A large European cohort study (EPI-CT) has been set up to further evaluate the potential risk of cancer associated with CT exposures in childhood.
 
Methods –EPI-CT uses a common protocol implemented in Belgium, Denmark, France, Germany, the Netherlands, Norway, Spain, Sweden and the United Kingdom. Demographic information and technical data on CT are obtained from records of radiology departments. Passive follow-up is conducted by linkage to population-based registries. Individual organ doses are estimated via a simulation approach which produces alternative realizations of doses. The feasibility of studying different biomarkers of radiation sensitivity at young ages was also tested.
 
Results – This study is unique because of its size (more than a million patients), sophisticated dosimetry and the attention paid to characterise possible bias factors including missing doses from other procedures or missed CTs, confounding by SES and by indication. It will strengthen the scientific evidence on the effects of low doses of ionizing radiation in young people.

Conclusions – To ensure that CT scanning remains beneficial, radiation dose should be kept as low as possible while ensuring sufficient diagnostic quality. Reducing exposure from CT scanning will impact the global cancer burden since the number of procedures increases worldwide.

Funding sources: This work was supported by the European Community’s Seventh Framework Programme (FP7/2007–2013) (grant number 269912). Complementary funding from ministries, national institutions and cancer associations was obtained in participating countries.