Since the risks associated with low doses of radiation from CT scans are expected to be small, a large multi-national collaborative study is needed to ensure sufficient precision and statistical power to study these effects. The present study, based on a common core protocol, aims to bring together the national studies already ongoing in France, Germany and the UK, and to set-up additional studies in five other European countries. In each country, cohorts of paediatric patients are assembled from the records of radiology departments with large numbers of paediatric populations. The patients will be followed over time to ascertain information on the incidence of leukaemia and possibly other cancers. Information on the CT procedures will be abstracted in order to calculate individual organ-specific dose estimates. This will allow comparing paediatric CT usage between regions and countries, describing organ-specific radiation dose estimates associated with CT scans, and quantifying associations with cancer incidence and with biological endpoints. The knowledge gained will be used to perfect imaging practices and techniques in paediatric health care settings in Europe and elsewhere.

Specific objectives of the project are to:

  • Establish a large multinational cohort of paediatric patients who received CT scans
  • Describe patterns of use of CTs over time and between countries
  • Develop individual estimates of organ-specific doses from paediatric CT scans using improved methods for dose estimation for paediatric patients
  • Evaluate the radiation-related risk of cancer in this cohort and pilot test biological markers of CT-irradiation effects
  • Develop methods to characterize quality of CT images in relation to the corresponding examination dose
  • Provide recommendations for a "harmonized" approach to CT dose optimization for paediatric patients in Europe