An audit of published South African diagnostic reference level data

Diagnostic reference levels (DRLs) are accepted as a dose optimisation tool for patients undergoing x-ray imaging and are required by South African (SA) legislation for 26 fluoroscopically guided procedures (FGPs). The aim of this paper is to collate all published SA data on DRLs in preparation for a project to establish national DRLs. Systematic searches were conducted of various applicable databases. All research that proposed DRLs for any imaging procedure in South Africa was included. Twenty-one works met inclusion criteria, the earliest from 2001. Two-thirds of all work reported on FGPs and five studies documented computed tomography DRLs. Three publications focussed exclusively on paediatric imaging DRLs. No studies on mammography or dental radiography were found. For clinical procedures with more than one proposed DRL, the range of proposed DRL varied by up to a factor of five. The highest proposed DRL is 373.1 Gy cm²for endovascular aneurysm/aortic repair procedures. Data were collected in six public hospitals and two private hospital groups. Thirty-six authors contributed to the manuscripts, but only six studies had an inter-disciplinary authorship. This is the first paper to provide a comprehensive review of SA DRL data and thereby advances international radiation protection initiatives. The data suggests there is room for more interdisciplinary work and that there must be rigorous standardization of reported parameters and data collection. This audit also highlights the need for standardized terminology, particularly for FGPs.