Establishing facility reference levels and comparing to international diagnostic reference levels in paediatric general X-ray.

Abstract

Diagnostic Reference Levels (DRLs) can be used to assess the radiation exposure for specific protocols and identify areas of potential optimisation. Despite paediatric general X-ray (GXR) being a relatively low dose modality, due to the high radiosensitivity of children, it is imperative that doses remain as low as reasonably achievable (ALARA). This study aims to compare our institute's Dose-Area-Product (DAP) to currently available local, national, and regional DRLs, as there are currently no Australian DRL values established for paediatric GXR. The DAPs for GXR protocols are recorded in a commercially available DMS software, MyXrayDose, which generates a report of the Facility Reference Levels (FRLs) for all GXR protocols. As MyXrayDose uses age categories, our FRLs were converted to weight-based FRLs using the 50th percentile values derived from the World Health Organisation and Centres for Disease Control Weight-for-age charts. These were compared to published DRLs from eleven different countries and regions of the world. Pelvis Anterior-Posterior (AP)/Posterior-Anterior (PA), Abdomen AP/PA, Thorax AP/PA and Thorax lateral protocols were compared to available national and regional DRLs. For example, from 1st July 2023-30th June 2024, 1008 Abdomen AP/PA X-rays were conducted in Room 1 with a fixed GXR unit. The FRL for 31.2-56.5 kg (10-15 years) patients in Room 1 (1093 mGy.cm²) was more than 2.3 times greater than the European DRL (475 mGy.cm²). The FRLs for patients with a mean weight of 6 kg and 14 kg were below the European DRL whilst 25 kg, 44 kg and 60 kg patients exceeded the European Abdomen AP/PA DRL. The establishment of DRLs helps institutes identify potential areas of optimisation. As some of our GXR protocols exceed the European DRLs, the next step at our institute is to complete a multi-disciplinary image quality assessment to identify if it is possible to optimise these protocols.