Diagnostic radiation represents an indispensable tool for modern medicine.
Physicians see benefits of using computerized tomography (CT) scanning in
their daily clinical practice. The growth of CT use in children has been
driven primarily by the reduction in the time needed to perform a scan.
As a consequence, it is now possible to perform more examinations in a given
time, extend the scope of some examinations, as well as introduce some new
techniques and examinations. The ease of acquisition of images results sometimes
in unnecessary exposure of patients to radiation, particularly in developed
countries. Furthermore, organ doses from CT scanning are considerably larger
than those from corresponding conventional X-ray. For example, a dose to
the stomach from a conventional abdominal x-ray examination is approximately
0.25 mGy, which is at least 50 times smaller than the corresponding stomach
dose from an abdominal CT scan (Brenner & Hall, 2007).
The growing use of CT technology despite the introduction and wider use
of other modalities, such as magnetic resonance imaging, raises concerns
in radiological protection, especially for children and adolescents. Children
are generally more sensitive to the carcinogenic effects of ionizing radiation
than adults. In addition, they may receive even higher radiation doses
from a CT procedure than an adult. The long-term risk of radiation induced
cancer or other health effects following CT scanning has not been directly
assessed, although the scientific knowledge so far does not exclude that
the ionizing radiation, which is emitted by CT, may cause cancer. No large-scale
epidemiological studies of health risks associated with this procedure
have been reported so far. The "Epidemiological study to quantify
risks for paediatric computerized tomography and to optimise doses"
(EPI-CT) was set-up to investigate the relationship between the exposure
to ionizing radiation from CT scans in childhood and adolescence and possibly
attributable late health effects. Eighteen centres from Belgium, Denmark,
Germany, Finland, France, Luxembourg, the Netherlands, Norway, Spain,
Sweden and the United Kingdom will cooperate in this project to enrol
approximately one million patients. The knowledge gained on current and
past CT examination practice will help to propose strategies for further
The EPI-CT study is coordinated by the Section of Environment and Radiation at the International Agency for Research on Cancer (IARC). The study received substantial financial support from the Seventh Framework Program of the European Commission (FP7-Fission-2010-3.2.1). Results are expected in 2015.