Occupational exposure to ionizing radiation in a nuclear medicine department: myth and reality

Nuclear medicine is a diagnostic and therapeutic medical specialty based on the administration of radiopharmaceuticals emitting ionizing radiation (IR). In this context, healthcare professionals are exposed to low doses of radiation during their activity. This review aims to provide an up-to-date overview of occupational exposures in nuclear medicine in France, based on data from the 2023 IRSN and 2024 ASN reports, and to put them into perspective with those of other medical or industrial sectors, as well as with natural background exposure. Occupational exposures in nuclear medicine remain very low: in 2023, the average annual dose for workers was 0.78 mSv, which is about three times lower than the average natural exposure in France. No regulatory exceedance was observed, either for external exposure, extremities of the limbs doses, or eye lens doses. Most reported significant radiation protection events are minor and without clinical consequence. Furthermore, this article recalls the historical background of the concept of maximum permissible dose and the principles of radiation protection, highlighting the limitations of the linear no-threshold (LNT) model applied to low doses on which these principles are based. Finally, it describes the organizational, technical, and individual measures implemented in nuclear medicine departments to maintain these low levels of exposure. These data confirm that this medical specialty remains one of the least exposed to occupational risks in the hospital environment.