SU‐E‐I‐91: The Role of Diagnostic Reference Levels in the Optimization of Patient Protection

Abstract

Purpose: The concept of Diagnostic Reference Levels (DRLs) has been around for over 20 years and is part of the regulatory framework of many countries. The International Basic Safety Standards (BSS) requires both the establishment and the use of DRLs for imaging procedures. However, the level of implementation around the world varies considerably, with many countries yet to establish DRLs for common procedures. This paper discusses the current experiences with DRLs and their strengths and limitations.Method and Materials: The published experiences of several countries are analyzed and discussed. Points considered include whether there is a need for strict criteria for patient selection or not, whether clinical purpose must be considered or whether body habitus is sufficient, whether DRLs should be set according to the technology used or not, and whether there is a role for international DRLs. Results: Countries that have had several cycles of DRLs have clearly demonstrated their effectiveness in optimization of protection. The initially held belief that the weight of patients included in samples needed to be carefully controlled may not be strictly necessary. DRL values should be based on the then current practice in a given country, and a priori, encompass all technologies and techniques in use. While clinical purpose ultimately determines the signal to noise ratio needed for imaging, for the purposes of DRLs as a blunt tool for identifying outliers, perhaps body habitus based DRLs are sufficient. Impediments to the establishment and use of DRLs include lack of resources, e.g. personnel, dosimeters, and custodians for a national patient dose database. Conclusion: DRLs are an important tool for optimization of protection, and the level of implementation around the world needs to improve. However they are not the only tool for optimization and parallel initiatives need to take place.