Date:
December 2022
Article publication date:
December 2022
Authored by:
Hauptmann et al.
Summary:
This cohort study, conducted in nine European nations, assessed the risk of brain cancer in children and young adults who undertook at least one computed tomography (CT) scan. People who had had one or more CT scans under the age of 22 between 1977 and 2014 and were not diagnosed with cancer for at least 5 years after the first CT scan were eligible to participate in this study. A total of 658,752 people met the eligibility criteria and were included in the study. Incidents of brain cancer were identified through national or regional cancer registries. Ionising radiation dose to the brain was calculated based on historical information on the CT machine settings, questionnaire data and metadata from a large sample of CT scans. The follow-up duration after 5 years from first CT scan for each participant was a median of 5.6 years (Interquartile range 2.4-10.1). This resulted in a total follow-up time of 4,536,716 person-years. In this period, there was a total of 165 cases of brain cancer, of which 121 (73%) were glioma. The average cumulative brain absorbed dose for all participants was 47.4 mGy , participants who developed brain cancer had an average cumulative dose of 76 mGy . A significant dose-response relationship was also found for all brain cancers with an excess relative risk (ERR) per 100mGy of 1.27 (95% Confidences Interval (CI) 0.51, 2.69) and for glioma separately (ERR per 100 mGy 1.11 95% CI 0.36, 2.59). The authors conclude that these findings emphasize the use of doses as low as reasonably possible and the need for careful justification of paediatric CT scans.
Link to:
Published in:
The Lancet Oncology
Commentary by ARPANSA:
The results of this study support previous research conducted in Australia (Mathews et al.), as well as a meta- analysis conducted by Little et al. (Little et al 2002a; Little et al 2022b), which show an increased risk of cancer following early life exposure to CT scans. The Code for Radiation Protection in Medical Exposure (2019) (RPS C-5) sets out the Australian requirements for the protection of patients, including young children, relating to their exposure to ionising radiation. Most diagnostic radiology procedures pose little risk, however, it is ARPANSA’s goal to ensure that the highest standard of protection is made available through the implementation of the relevant Codes and Safety Guides. These safety materials give practitioners in diagnostic and interventional radiology a best practice approach to their day-to-day clinical work. ARPANSA advises parents concerned about their children’s exposure from radiological procedures to talk to the doctor requesting the radiological procedure. The child’s doctor and the staff at the radiology facility work together on which tests are required and evaluate the risks and benefits in each child’s individual circumstances. It is important that CT scans in young people are justified and the radiation dose is as low as reasonably achievable.
