Interpretation and implementation of adult diagnostic reference levels in nuclear medicine and PET in the UK

In the UK, the Administration of Radioactive Substances Advisory Committee (ARSAC) sets and publishes National Diagnostic Reference Levels (NDRLs) for diagnostic nuclear medicine (NM) and Positron Emission Tomography procedures. This article summarises how these NDRLs should be applied and used within the UK and proposes a new model on how they are set. As an exemplar, the results of a recent survey of administered activities in the UK for 18 F-fluorodeoxyglucose (FDG) for whole-body tumour imaging and infection inflammation imaging are presented here. ARSAC recommends that the UK NDRLs for NM or PET examinations are set as either a fixed activity (MBq) or by administered activity per body weight (MBq/kg). ARSAC proposes setting the first weight-based activity scaling NDRLs for 18 F-FDG whole-body tumour imaging and 18 F-FDG infection inflammation imaging to 3.5 MBq/kg.