RESUMEN
PRINCIPLES: Plain lumbar spine radiographic examination (LSRE) is frequently used in medical practice and delivers a high dose of ionising radiation. The objectives of the study were to determine the annual frequency of LSRE in Switzerland and its distribution according to practitioners' and patients' characteristics, as well as the related population dose of ionising radiation. METHODS: Data were extrapolated from a nationwide questionnaire survey on radiation exposure resulting from medical imaging in 1998, involving physicians and other healthcare providers performing radiological examinations in Switzerland. RESULTS: An estimated number of 273,000 LSRE are performed annually in Switzerland (39 LSRE per 1000 inhabitants per year). The collective dose to the population due to LSRE was 1130 Sv (0.16 mSv per person per year). 50-60% of these procedures were performed to confirm or rule out a diagnosis, the majority (85%) in the context of an illness. CONCLUSIONS: LSRE is the third most frequent radiographic procedure performed and delivers the highest population dose of ionising radiation of any radiodiagnostic procedure. Efforts to reduce the frequency and the radiation dose of this procedure must be kept up, technically by optimising the equipment and radioprotection measures, and clinically by implementing evidence-based approaches to appropriate indications for this imaging technique.