Patient dose protocols and trends in the UK

NRPB has been conducting national patient dose surveys in the UK over the past decade and has published advice and recommendations on patient dose reduction in collaboration with appropriate professional and regulatory bodies. To support these recommendations, a national protocol for patient dose measurements in diagnostic radiology was published in 1992 describing suitable dose measurement techniques and providing national reference doses for common types of X ray examination. It also asks medical physicists to send the results of local measurements to NRPB so that a national database can be established. The methods for patient dose measurement and for setting national reference dose levels recommended in the UK protocol are briefly described. Data collected up to August 1993 in the national database are reviewed. Trends in patient doses over the last decade in the UK are assessed to provide a measure of the impact of the initiatives for optimisation, quality assurance and patient dose reduction that have been applied to diagnostic radiology during this period. Comparisons are made with similar data from the USA.