LES ACTIVITÉS NUCLÉAIRES : RAYONNEMENTS IONISANTS ET RISQUES POUR LA SANTÉ ET L’ENVIRONNEMENT HIGHLIGHT No. 6 Patient cohorts in conventional and interventional radiology In 2025, several significant radiation protection events involving cohorts of patients were reported to ASNR in conventional and interventional radiology. These events, described below, constitute a milestone for the year 2025 (see Notable Events in the introduction section of this report). Overexposure of a patient cohort in fluoroscopy-guided conventional radiology On 20 December 2024, a hospital notified an ESR to ASNR following the discovery of an abnormally high radiation dose in the examination report of an eight-year-old child. The investigation attributed this overexposure to an incorrect configuration of the radiology table, which had remained in place since 2012. A total of 667 patients, including 451 children, were exposed to doses above the reference levels. The underlying causes included an inadequate optimisation process, particularly the absence of dose reporting in procedure reports and the lack of analysis of delivered doses, as well as insufficient staff training in a context of high staff turnover. The facility carried out a dosimetric reconstitution for examinations carried out since 2017, as the period 2012-2016 could not be assessed due to the absence of dose records. The results, assessed by ASNR, confirm the absence of deterministic short-term effects for all patients. Furthermore, in accordance with ICRP criteria, the risk of long-term stochastic effects for these patients, compared with the general population, is considered to be low to very low. The Hospital Centre provided personalised and comprehensive information to all patients exposed, in coordination with the health authorities. Immediate corrective action was taken as soon as the incident was detected. Table settings were corrected, personnel were trained and internal Diagnostic Reference Levels (DRLs) were defined to serve as alert thresholds. Automatic and systematic inclusion of dose information in procedure reports has now been implemented. Additional measures planned at the end of the year included the formalisation of protocols (including for at-risk patients), implementation of a competency sign-off process for imaging professionals, and consideration of replacing the equipment with a more recent model incorporating a DACS dedicated to dose archiving and monitoring. This ESR highlights the importance of rigorously applying the optimisation principle (ALARA(*)/ALADA(**)), as required by Article R. 1333-68 of the Public Health Code. ASNR emphasises that regular and systematic dose analysis (including comparison with DRLs) and mandatory inclusion of dose information in procedure reports constitute essential safety barriers. ASNR is working with its Imaging Operating Experience Feedback (OEF) Working Group, which brings together healthcare professionals and healthcare authorities, to draw up a feedback form to prevent such incidents from recurring, stressing that a high level of radiation protection depends on a solid radiation protection culture, supported by trained and qualified professionals and equipped with appropriate monitoring tools. Paediatric examinations performed using incorrect parameters on conventional radiology equipment On 25 June 2025, a hospital notified an ESR to ASNR concerning a cohort of at least 140 children aged between one month and ten years who underwent conventional thoracic radiology examinations during the period 2024–2025. The issue was identified by the hospital as part of its dose optimisation process through comparison of patient dose data with the Diagnostic Reference Levels (DRLs) applicable to conventional radiology examinations performed on children weighing between 20 and 30 kg. The facility’s results showed values significantly higher than expected. The radiology table is used by the hospital centre to carry out a number of radiological examinations on outpatients or inpatients from internal departments (paediatric emergency, maternity), such as chest or pelvic X-rays, for both children and adults. The causes of the observed over- exposure appear to be multiple: radiology table settings that had not been adapted to paediatric use since the equipment was commissioned in 2013, together with shortcomings in the facility’s optimisation process, particularly insufficient monitoring of doses received by patients. Investigations were undertaken to identify patients potentially affected by overexposure since the equipment was commissioned. However, consolidation of the list of affected patients proved difficult because there was no automated dose collection system and no image archiving system, preventing electronic access to patient dose data. The hospital took immediate steps after the event was discovered to prevent such overexposures from recurring. The decision was taken to suspend paediatric use of the room temporarily, and the external medical physics outside contractor engaged by the hospital was asked to assess the protocols configured on the radiology table. The radiology table protocols were subsequently revised and verification was carried out to ensure that delivered doses were consistent with the DRLs applicable to paediatric examinations. At ASNR’s request, the hospital reconstructed the doses received by the five most exposed patients in order to assess potential consequences. The results of these dosimetric reconstructions showed that the doses received remained very low and that no clinical consequences were expected. Patients affected by the overexposure during conventional thoracic radiology examinations performed between 2024 and 2025 were informed. Dose levels have been determined to serve as a reference for the teams, so that any anomalies during an examination can be detected quickly. Doses are now automatically entered in the procedure reports, so that the dose delivered to each patient can also be checked. These measures form part of the optimisation approach that all practitioners using ionising radiation must implement. In addition, the acquisition of a Dose Archiving and Communication System (DACS) is being considered in order to facilitate automated use and analysis of dose data. This ESR highlights the need to optimise equipment from commissioning and throughout its operational life, and to ensure that the professionals using it are appropriately trained and formally authorised to do so. Analysis of quality controls, regular collection of data on doses delivered to patients, implementation of regular dosimetry assessments, analysis of the results of these assessments and comparison of the latter with national Diagnostic Reference Levels (DRLs), where they exist, are all barriers enabling teams to be rapidly alerted to malfunctions or inappropriate use. This event also highlights the importance of connecting radiology equipment to a DACS to facilitate analysis of the doses delivered. Overexposure of a cohort of conventional radiology patients On 16 June 2025, a hospital notified a Significant Radiation Protection Event (ESR) to ASNR, affecting 46 patients. The event was discovered on 10 June 2025, when an Electroradiology Manipulator (MERM) noticed high exposure constants on the images of thoracic examinations carried out with a Calypso DR radiology system from PRIMAX. Commissioned on 14 December 2024, the equipment underwent corrective maintenance on 5 June 2025 following a breakdown. Following the identification and correction of several malfunctions (deactivation of cells enabling automatic adjustment of exposure parameters during examinations, additional filtration not configured in clinical protocols, etc.), the doses delivered still appeared higher than expected. An analysis of the period from 14 December 2024 (when the device was commissioned) to 10 July 2025 shows that 3,446 patients were treated for chest examinations, including 26 children. Of these, 703 patients, including 4 children, received a dose significantly higher than the reference dose for this test. The medical physics department carried out a dosimetric reconstitution for the most exposed patients to assess the consequences. * ALARA : “As Low As Reasonably Achievable” – Principle aimed at avoiding unjustified exposures. ** ALADA : “As Low As Diagnostically Acceptable” – Principle aimed at optimising the dose to be administered. 218 ASNR Report on the state of nuclear safety and radiation protection in France in 2025
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