An audit of radiation doses received by paediatric patients undergoing computed tomography investigations at academic hospitals in South Africa

BACKGROUND: Diagnostic reference levels (DRLs) are a crucial element of auditing radiation doses in paediatric computed tomography (CT). Currently, there are no national paediatric CT DRLs in South Africa. OBJECTIVES: The aim of this article was to establish local paediatric DRLs for CT examinations at two academic hospitals and to compare paediatric CT radiation output levels with established DRLs in the developed and developing world. METHOD: Computed Tomography Dose Index(volume) (CTDI(vol)) and dose length product (DLP) values were collected from CT examinations performed at two university hospitals for patients aged 0–15 years, during 01 November 2016–30 April 2017. The 75th percentile of the data distribution was calculated for each CT examination type and age group, further categorised into routine working hours and after-hours for both hospitals and statistically compared. RESULTS: Of the 1031 CT examinations performed, CT brain examination was the most common (755/1031; 72.23%). DLP values were increased in the after-hours categories compared to regular working hours at both hospitals. The largest increase was in the 0–1 year age group (150.56%). With the exception of CT Chest and CT abdomen in the 0–1 year age group, the CTDI(vol) and DLP values compared favourably to international standards. CONCLUSION: Most of the calculated DRLs are acceptable and internationally comparable. This likely indicates effective reduction techniques and protocols. Computed tomography body examination protocols for 0–1 year patients should be reviewed. Strategies should be implemented to limit higher doses in after-hours examinations.