The application of diagnostic reference levels: General principles and an Irish perspective

The principles of justification and optimisation, and the establishment and use of diagnostic reference levels (DRLs) are core tenets of the European Medical Exposures Directive [Council Directive 97/43], and ensuing legislation across Europe. This is the third in a series of three review articles: the previous two discussed the principles of justification and optimisation, the current review covers the concept of DRLs.In this paper, a brief synopsis of the history of DRLs is presented, and their possible applications are outlined. Approaches and progress with DRLs in a number of European countries, as derived from published literature, are summarised and a comparison of the approaches highlights some practical issues in using DRLs. Irish data are then considered in the context of literature ensuing from SI478 of 2002, and relating to the establishment of national diagnostic reference levels.The reviewed literature supports the opinion that national DRLs are preferable to those drawn from pan-European dose data.