The concept of national reference doses was first introduced in the United Kingdom in 1980s, after a national survey of doses from some common X-ray procedures [1]. The International Commission on Radiologic Protection (ICRP) introduced diagnostic reference levels in 1990 and further developed the concept in publications 73, 105 and 135 [2]. The International Basic Safety Standards from 1996 defined "guidance level", the term that has been replaced with "diagnostic reference level" (DRL) in the latest International Basic Safety Standards published in 2014 in the...

1. Safety Guide SSG-46 The IAEA published in 2018 a new Safety Guide on Radiation Protection and Safety in Medical Uses of Ionizing Radiation, SSG-46 [4] whichrecommends how medical uses of ionizing radiation should be carried out safely within the framework of GSRPart3. The documents gives additional recommendations on setting and using DRLs, in line with the ICRP Publication 135 [2]. There are several steps to the establishment of DRLs: Establish working group; appoint coordinator and administrator of the database; Decide for which imaging procedures...

DRLs are an important tool and should be used for optimization of protection and safety for diagnostic medical exposure. The IAEA provides support to its Member States through guidelines, training and expert support. Few new activities related to DRLs are under development: Publication in the IAEA Safety Report Series "Patient Radiation Exposure Monitoring in Medical Imaging", under development, with contribution from the ICRP, WHO, UNSCEAR, and the Working Group 28 (Physics) of DICOM. IAEA training package and e-learning on Establishment and Utilization of Diagnostic Reference...

Jenia Vassileva Radiation Protection Specialist Radiation Protection of Patients Unit Division of Radiation, Transport and Waste Safety Department of Safety and Security International Atomic Energy Agency Vienna, Austria

1. Shrimpton PC, Wall BF, Jones DG, et al. A national survey of doses in patients undergoing a selection of routine x-ray examinations in English hospitals. NRPB–R200. Oxfordshire, United Kingdom: National Radiological Protection Board, 1986 2. International Commission on Radiological Protection, Diagnostic Reference Levels in Medical Imaging, Publication 135, SAGE Publications, 2017. 3. European Commission, Food and Agriculture Organization of the United Nations, International Atomic Energy Agency, International Labour Organization, OECD Nuclear Energy Agency, Pan American Health Organization, United Nations Environment Programme, World Health Organization,...