The detectors present on the devices with C-arms are image intensifiers or flat panel detectors. These devices employ techniques that use fluoroscopy and dynamic radiography (called “photofluorography”, or “cineradiography”) intended to produce high-resolution spatial images. Practitioners can also use the subtraction method to obtain images, after injecting a contrast agent. Operating theatres are being equipped with ever-more efficient and sophisticated medical devices. These are mobile CT scanners or fixed C-arms in “hybrid” rooms which combine the characteristics of a conventional surgical room with those of an interventional imaging room; this combination enables the surgeon to perform “mini-invasive” surgery with 2D and 3D imaging. Fixed CT scanners coupled to fixed C-arms are also beginning to be installed in health care centres. If used without specific dose-reduction technology, these devices can expose the patient and the medical staff –who most often work in the immediate vicinity of the patient– to higher dose levels than during other interventional practices. In these conditions, given the exposure risks for both the operator and the patient, practices must be optimised to reduce doses and ensure the radiation protection of operators and patients alike. In 2021, the ASN regional divisions issued 335 FGIP notification acknowledgements, fewer than in 2020 due to the introduction of the new registration system, put in place since 1 July 2021. The need for better knowledge of the FGIPs implemented in the centres and the need to check the facilities for conformity with the applicable fitting out rules before they enter service, has led ASN, in a graded approach to the radiation protection risks, to subject these activities to this new system, which corresponds to a simplified authorisation. 2.4.2 Technical rules for fitting out medical rooms The rooms in which FGIPS are carried out, operating theatres and interventional imaging rooms, must be organised in accordance with the provisions of ASN resolution 2017-DC-0591 of 13 June 2017 laying down the technical design rules to be satisfied by rooms in which electrical devices emitting X-rays are used. The design rules for the rooms, set by the above resolution, aim to protect the workers by limiting their exposure to ionising radiation. The arrangements must make it possible for any member of personnel entering a room in which an electrical device emitting X-rays is present and used –the operating theatre in this case– to assess the risk in order to take appropriate radiation protection measures on entering or when inside the room. With regard to signalling systems, they are obligatory at the point of access to the operating rooms and inside the rooms when a device is present and to signal the emission of radiation. It is important to point out that many medical and nonmedical staff members intervene in the operating theatre. Simple and practicable instructions must be favoured in a context of multiple risks and a complex environment. The signalling systems moreover count among the most effective prevention measures, as does the wearing of appropriate personal protective equipment and dosimeters by each operator, from the moment a restricted area is delimited due to the risk of exposure to ionising radiation. 2.4.3 Radiation protection situation in fluoroscopy-guided interventional practices For several years now, ESRs have been regularly reported to ASN in the area of FGIPs. Although these events represent just a small proportion of all the medical events reported to ASN, the doses administered are high (for a diagnostic activity) and sometimes exceed the dose thresholds beyond which tissue damage occurs (radiodermatitis, necrosis) in patients having undergone particularly long and complex interventional procedures. In addition to these events, which underline the major radiation exposure risks for the patients, are those concerning professionals, whose exposure can lead to the exceeding of regulatory dose limits, particularly at the extremities (fingers). GRAPH Percentage conformity of the FGIP facilities inspected on the theme of radiation protection of medical professionals in 2021 10 0% 20% 40% 60% 80% 100% RPE-O with valid certificate Sufficient and suitable dosimeters Dosimetric results analysed and any discrepancies explained Coordination of preventive measures established with all external companies 100% of medical workers trained in radiation protection for less than 3 years 100% of paramedics trained in radiation protection for less than 3 years Delimitation of regulated areas consistent with regard to ambient dosimetry FGIP in operating theatre FGIP in interventional imaging 222 ASN Report on the state of nuclear safety and radiation protection in France in 2021 07 – MEDICAL USES OF IONISING RADIATIONS
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