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Childhood exposure to ionizing radiation from computed tomography imaging in Nova Scotia
Mark Inman1, Anthony Otley1, Trevor Dummer2
1Department of Paediatrics, Dalhousie University; IWK Health Centre;
Insights
Paediatric computed tomography (CT) use decreased significantly in younger children but increased in adolescents. While overall CT rates remained stable, targeted efforts are needed to reduce high radiation doses in older youth.
Area of Science:
- Radiology and Imaging
- Paediatric Health
- Radiation Oncology
Background:
- Paediatric patients are uniquely vulnerable to radiation due to radiosensitive tissues and longer life expectancy.
- Assessing radiation dose in children is critical for mitigating long-term risks, including radiogenic malignancy.
Purpose of the Study:
- To analyze trends in computed tomography (CT) utilization and ionizing radiation exposure among paediatric populations.
- To use population-based data from Nova Scotia for evaluating these trends.
Main Methods:
- A retrospective, population-based cohort study was conducted on patients under 20 years old in Nova Scotia.
- Data from January 1, 2004, to December 31, 2011, were analyzed from a provincial imaging repository.
- Trends in CT use and cumulative effective dose exposures were calculated.
Main Results:
- A total of 29,452 CT events involving 22,867 individuals were analyzed.
- Overall annual paediatric CT rates were static (17.4–18.8 per 1000).
- CT use decreased by over 50% in children under 10, while increasing in adolescents aged 15–19. 1.6% of patients exceeded 50 mSv.
Conclusions:
- CT use in younger children (<15 years) significantly decreased, potentially due to increased awareness and guideline changes.
- Conversely, CT use in adolescents (≥15 years) steadily increased.
- Further efforts are required to reduce radiation exposure, particularly for the subgroup receiving high doses and the growing adolescent population.
Background:
Examining radiation dose in the paediatric population is particularly important due to the vulnerability of paediatric patients (increased radiosensitive tissues and postexposure life-years) and risk for future radiogenic malignancy.
Objectives:
To evaluate trends in paediatric computed tomography (CT) use and ionizing radiation exposure using population-based data from Nova Scotia.
Methods:
A retrospective, population-based cohort study of CT use in patients <20 years of age, from January 1, 2004 to December 31, 2011, was performed in Nova Scotia. CT examination data were retrieved from a provincial imaging repository. Trends in CT use were described, and both annual and cumulative effective dose exposures were calculated.
Results:
In total, 29,452 CT events, involving up to 22,867 individuals were retrieved. Overall annual paediatric CT examination rates remained static (range 17.4 to 18.8 per 1000 per year). However, use in children <10 years of age decreased by >50% (P<0.001); this was counterbalanced by a steady increase among 15- to 19-year-olds (P<0.0001). Overall, 15.4% of scanned patients underwent ≥2 examinations, of which 58 patients (1.6%) exceeded 50 mSv of exposure.
Conclusions:
Despite a static rate in CT imaging among the entire cohort, children <15 years of age and, particularly, those <10 years of age displayed marked reductions in CT use. This may reflect increased awareness of campaigns emphasizing judicious CT use, revised clinical practice guidelines and increased availability of alternative modalities. A small subgroup demonstrated high-dose exposure (>50 mSv), and rates in individuals >15 years of age steadily increased, suggesting further exposure reduction efforts are necessary.
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