Age-based diagnostic reference levels and achievable doses for paediatric CT: a survey in Shanghai, China

Abstract

Computed tomography (CT) is extensively utilized in medical diagnostics due to its notable radiographic superiority. However, the cancer risk associated with CT examinations, particularly in children, is of significant concern. The assessment of cancer risk relies on the radiation dose to examinees. Diagnostic reference levels (DRLs) and achievable doses (ADs) were used to assess the level of radiation dose in CT examinations widely. Although the national DRLs of pediatric CT have been explored in China, few local DRLs at the city level have been assessed. To set up the local DRLs and ADs of pediatric CT, we investigated the radiation dose level for pediatric CT in Shanghai. In this survey, a total of 3 061 pediatric CT examinations underwent in Shanghai in 2022 were selected by stratified sampling, and the dose levels in terms of volume CT dose index (CTDIvol) and the dose-length product (DLP) were analyzed by 4 age groups. The DRLs and ADs were set at the 75th and 50th percentile of the distribution and compared with the previous studies at home and abroad. The survey results revealed that, for head scan,theDRLs of CTDIvol were from 25 to 46 mGy, and the levels of DLP were from 340 to 663 mGy·cm. For chest, the DRLs of CTDIvol were from 2.2 to 8.3 mGy, and the levels of DLP were from 42 to 223 mGy·cm. For abdomen, the DRLs of CTDIvol were from 6.3 to 16 mGy, and the levels of DLP were from 181 to 557 mGy·cm. The ADs were about 60 percent lower than their corresponding DRLs. The levels of radiation doses in children-based hospitals were higher than those in other medical institutions. (P<0.001).In conclusion, there was still potential for reducing radiation dose of pediatric CT, emphasizing the urgent need for optimizing pediatric CT dose in Shanghai.