An approach to local diagnostic reference levels (DRL's) in the context of national and international DRL's

In recent years there has been a greater focus on the management of patient doses. This effort has been driven by the realisation of both the increasing magnitude of patient doses and their variation both intra- and inter-nationally. Legislators and guidance-issuing bodies have developed the idea of 'Diagnostic Reference Levels' (DRL's). In particular, the European Union, in their Council Directive 97/43/Euratom, required Member States to develop DRL's. The UK Government, when consolidating this EU Directive into UK legislation, extended the concept of DRL's from a national to an employer level. However, the methodologies used for development of national and international DRL's do not translate to a local level and hence a new approach is required. This paper describes one particular approach made by a UK hospital to introduce 'Local DRL's' in such a manner as to aid the optimisation process. This approach utilises a dose index, based on the local patient population, which is monitored for trends. Any trend in patient dose triggers an investigation linked to the clinical audit system within the Clinical Radiology Department. It is the audit cycle that ensures a continuing move towards an optimised situation. Additional triggers may be employed such as large patient dose variations. (author)