LES ACTIVITÉS NUCLÉAIRES : RAYONNEMENTS IONISANTS ET RISQUES POUR LA SANTÉ ET L’ENVIRONNEMENT annual individual dose received remains very limited, at around 0.06 millisieverts (mSv) in the medical field (excluding dentistry) and 0.03 mSv in the dental field (see chapter 1). Among the health personnel liable to be exposed and therefore subject to dosimetry monitoring, those working in radiology (80% of the medical personnel monitored, in diagnostic radiology and interventional radiology alike) receive an average individual annual dose of 0.03 mSv. The nuclear medicine personnel, who represent 6% of the monitored health personnel, are exposed to an average individual annual whole body dose that is fifteen times greater, estimated at 0.45 mSv. Workers involved in transporting radiopharmaceutical products for nuclear medicine departments are also particularly exposed, with an average annual dose of 1.06 mSv. Prospects for the development of ITR could increase these challenges, which is why ASNR is keeping a particularly close eye on them. It is also in the medical sector that the majority of situations of occupational exposure to the extremities (hands) occur. Consequently 12,739 medical professionals were subject to dosimetric monitoring of the extremities by ring or wrist dosimeter, which represents 58% of the workers monitored in this way and about 55% of the total dose to the extremities. The radiology sector has the largest number of monitored workers, with about 67% of the total headcount of medical personnel monitored by dosimetry at the extremities (51% for interventional radiology and 16% for diagnostic radiology), and accounts for 20% of the total exposure dose to the extremities in the medical field. The nuclear medicine sector represents 24% of the monitored personnel and accounts for 78% of the total dose in this area. The contribution of interventional activities to the total dose is probably underestimated, particularly due to insufficient use of extremity dosimeters by personnel in the operating theatre. Lastly, 82% of the personnel monitored for exposure to the lens of the eye work in medical activities, representing 4,072 workers accounting for 47% of the total dose to the lens of the eye. The average individual dose for medical activities (dental activities excluded) in 2024 was 0.21 mSv. Nearly 77 % of the personnel monitored for lens of the eye dosimetry work in the FGIP sector which accounts for 79% of the total dose in the medical sector. 1.2.2 – Exposure of patients In medical applications for diagnostic purposes, the aim of optimising exposure to ionising radiation is to deliver the minimum dose that produces an image of sufficient quality to obtain the relevant diagnostic information or allows performance of the planned interventional procedure. Therapeutic applications, where the aim is to destroy cancer cells, involve delivering a much higher dose than for diagnostic applications, while preserving neighbouring healthy tissue as much as possible. As the principle of limitation does not apply to patients, the principles of justification and optimisation (see point 1.3) must be applied all the more rigorously. In medical imaging, the principles of optimisation and justification (avoiding unnecessary examinations, or those whose result can be obtained using non-irradiating techniques that give an equivalent diagnostic level when available) are at the centre of the action plans for controlling doses delivered to patients. These action plans were developed by ASN in 2011 and 2018 in collaboration with the services of the Ministry of Solidarity and Health and the health professionals. On 10 October 2025, ASNR convened a meeting of the members of the National Imaging Committee (CNI). This Committee is an expert and coordinating group set up to oversee radiation 2. The ALARA (As Low As Reasonably Achievable) principle appeared for the first time in Publication 26 of the International Commission on Radiological Protection (ICRP) in ICRP publication 26 of 1977. It was the culmination of a review of the principle of radiation protection optimisation. Acceptance and implementation of the ALARA principle have evolved significantly in Europe over the last thirty years, with close involvement of the European Commission which resulted in the creation of a European ALARA network in 1991. protection and improve the quality of medical imaging practices using ionising radiation in France. It plays an important role in disseminating a culture of radiation protection among professionals and in implementing the principles of justification and optimisation, by strengthening skills and harmonising practices. The meeting was attended by representatives of 20 national councils of self-regulating healthcare professionals and professional associations, as well as representatives of the Ministry of Health, the French National Agency for the Safety of Medicines and Health Products (ANSM) and the French National Cancer Institute (INCa). In particular, it provided an opportunity to review the actions taken under the 2nd national plan to control imaging doses, focusing on the five actions that had not yet been completed: raising general practitioners’ awareness of the principle of justification; implementing peer clinical audit procedures (both internal and external); clarifying the situation regarding continuing training in patient radiation protection for professionals other than radiographers (MERM), physicians and dentists who may participate in procedures involving ionising radiation; defining the scope of outsourced medical physics services; and, finally, improving the deployment and interoperability of medical information systems to facilitate data exchange between healthcare professionals. An updated version of the plan will be published in early 2026. The optimisation principle, defined by Article L. 1333‑2 of the Public Health Code (see chapter 2), known as the ALARA(2) principle, has led to the introduction, in the area of medical imaging using ionising radiation, of the concept of “Diagnostic Reference Levels” (DRLs). The DRLs should not be equated with “dose limits” or “optimum doses”. The DRLs are thus dosimetric indicators used to assess the quality of practices. They are meaningful only for assessing average practice (based on groups of patients). Therefore, the comparison of a DRL value with a dose received during an individual examination is not relevant for a given individual, because in certain situations the conditions of the examination can justify a higher value (to take into account the patient’s morphology for example, or other factors that do not call into question the benefit/risk ratio of the procedure). The optimisation principle should lead the persons/entities Responsible for a Nuclear Activity (RNAs) that use imaging by ionising radiation to compile their own Local Dose Reference Levels (LDRLs) to continue optimising their practices if this is compatible with obtaining a diagnostic quality image. ASNR encourages such pr ctices and wants medical professionals to generalise them in the interest of the patients. ASN resolution 2019-DC-0667 of 18 April 2019 sets the DRL values and requires heads of radiology and nuclear medicine departments to carry out (or have others carry out) periodic dosimetric evaluations and to send the results to ASNR. The data collected is analysed with a view to updating the DRLs. This resolution will be amended in 2026 to introduce new DRL values for DR (Digital Reconstruction) mammography and tomosynthesis mammography; for dental CBCT (Cone Beam Computed Tomography); to strengthen dosimetric analyses for conventional radiology in paediatrics; and to specify the expectations for setting DRLs. The last “ExPRI” study, which analyses exposure of the French population to ionising radiation due to medical imaging examinations, was published by ASNR in late May 2025. It presents the data for 2022, which are compared with those of 2017 to show how they have evolved. These analyses are carried out using diagnostic imaging procedures drawn from a representative sample of people using the French health insurance system, by method of imaging (conventional, interventional and dental radiology, CT scans and ASNR Report on the state of nuclear safety and radiation protection in France in 2025 191 01 05 02 03 04 09 06 10 07 11 13 08 12 A / Z
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