operating theatres in several surgical specialities such as vascular surgery, gastroenterology, orthopaedics and urology. 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 highresolution spatial images. Practitioners can also use the subtraction method to obtain images, after injecting a contrast agent. The centres practising FGIPs are equipped with evermore efficient and sophisticated medical devices. “Hybrid” operating room facilities, which combine the characteristics of a conventional operating theatre with those of an interventional imaging room, are continuing to develop. These operating rooms contain fixed or mobile C-arm units and fixed or mobile scanners. This combination enables the surgeon to perform “mini-invasive” surgery with 2D and 3D imaging. If used without specific dosereduction technology and without mastering the principles of radiation protection, 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. 2.4.2 Technical rules for the fitting out of 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, 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 non-medical staff members intervene in the operating theatre in particular. 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 some years now ASN has been receiving regular reports on ESRs in the area of FGIPs, but their number is low compared with the number of procedures performed. In the course of its inspections, ASN finds that the medical professionals lack knowledge of the criteria for reporting significant events, even though the doses administered in some centres are high (for diagnostic activities) 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) and the lens of the eye. Ever more efficient and sophisticated techniques are developing in environments with little experience of the radiological risk. In this context, it is essential to optimises the doses, as much for the patients as for the personnel. This is why ASN’s inspections focus in particular on the rules for the fitting out of premises, the delimiting and signalling of restricted areas, dosimetric and medical monitoring of the personnel, the provision of personal protective equipment. Concerning patients, particular attention is paid to the optimisation of doses delivered to the patient (putting in place DRL and dose analysis), personnel training in patient radiation protection and the use of the medical devices. Application of resolution 2019-DC-0660 of 15 January 2019 setting the quality assurance requirements for medical imaging procedures that use ionising radiation helps the centres to manage the risk associated with ionising radiation. As FGIPs are numerous, varied, and performed in many different departments (neuroradiology, interventional cardiology, interventional radiology and operating theatres) within a given centre, the inspection programme is established so that all the departments performing radiation-risk procedures are inspected every 5 years. Inspection prioritisation is based on the number of procedures performed within a centre, the nature of the procedures which determine the radiation protection risks for the patients and medical staff, the condition of the facilities, (compliance with facility fitting out rules), the radiation protection culture of the teams and the situational factors (ESRs, vulnerabilities identified in previously inspected centres). Some 150 to 200 inspections are carried out each year. In 2022, the operating theatre complexes of the university hospital centres and the largest hospital centres, and the departments licensed by the ARS (licensed for treatments in cardiac rhythmology, interventional cardiology and neuroradiology) were prioritised. One hundred and thirty-four centres were thus inspected, representing a total of 209 departments performing FGIPs. 60% of the inspections in 2022 were carried out in operating theatre departments. Since 2018, ASN prioritises its inspections in the operating theatres where the radiation protection culture is the poorest. Characteristics of the inspected departments The 209 departments having undergone an inspection in 2022 can be broken down as follows: ∙ the 83 interventional imaging departments inspected comprise 25 coronary angiography departments, 29 cardiac rhythmology departments, 23 interventional vascular and osteoarticular radiology departments and 6 neuroradiology departments. 56 had at least one fixed C-arm, 14 had mobile C-arms and 4 had fixed CT scanners; ∙ of the 126 operating theatre departments inspected in 2022, 109 had at least one mobile C-arm, 8 had fixed arms and 2 had a mobile CT scanner. In 2022, 56% of the interventional radiology departments and 39% of the operating theatres have rooms conforming to the requirements of ASN resolution 2017-DC-0591 of 13 June 2017 setting the technical fitting out rules and have drawn up a conformity report. These percentages have varied little over the last four years. The centres must cope with financial difficulties, and bringing the operating theatre rooms into conformity still comes up against technical difficulties in meeting the requirements for lighted signalling of restricted areas. ASN Report on the state of nuclear safety and radiation protection in France in 2022 227 • 07 • Medical uses of ionising radiation 07 01 08 13 AP 04 10 06 12 14 03 09 05 11 02
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