Epidemiological study to quantify risks for paediatric computerized tomography and to optimise doses

The use of diagnostic radiation techniques represents an indispensable, sometimes life-saving, tool in modern medicine. The increasing use of diagnostic radiation techniques in children and teenagers, and in particular the use of high doses is a topic of particular concern in radiological protection and public health. Studies of atomic bomb survivors and other populations with medical and environmental exposures suggest that children are generally more sensitive to the health effects of radiation than adults. In addition, children have a longer life expectancy than adults and consequently a longer period in which to develop radiation-related health effects. Owing to their lower mass, children tend to receive higher organ doses from these procedures than adults if procedures are not specifically adapted for paediatric applications.

A large-scale multinational collaborative study has been set up with the objective of providing guidance towards optimisation of doses from paediatric computerized tomography (CT) scans. The specific aims of the EPI-CT study are as follows:

• Describe the pattern of use of CT in different countries and over time;
• Derive individual estimates of organ doses;
• Directly evaluate radiation-related risk of cancer following CT examination; and
• Characterize the quality of CT images in relation to the estimated doses in order to better inform CT imaging practice.

EPI-CT will comprise one of the largest paediatric cohorts for retrospective and prospective follow-up with the aim of detecting potential cases of cancer attributable to exposure and will thereby contribute novel evidence to the existing scientific literature. The main goal is to integrate the cohort studies currently being carried out in Europe (in France and the United Kingdom) and to set up additional studies in eight European countries (Germany, Belgium, Denmark, Spain, Finland, Norway, the Netherlands and Sweden) under the coordination of the International Agency for Research on Cancer (IARC) of the World Health Organization (WHO), jointly with scientists of several countries.

In Spain, the EPI-CT study is being conducted in the autonomous communities of Catalonia, Basque Country, Madrid, Murcia, Navarra and Valencia.

ISGlobal (former CREAL) coordinates the EPI-CT study in Spain. It also plays a leading role in the international coordination of the project, as a part of both the international Steering Committee and the Advisory Board. Within the EU grant, ISGlobal (former CREAL) leads the work package on Epidemiological Methods and the task dealing with analysis of risks of childhood leukaemia in relation to radiation dose from CT. Epi-CT is a European collaborative study aimed at assessing potential health risk from paediatric CT and optimising doses in medical imaging. Information is available at: epi-ct.iarc.fr