ASN Report 2018

published a report on proton therapy treatment indications and possibilities. Hadron therapy with protons is currently used in three centres in France: ∙ ∙ in the Curie Institute of Orsay (equipment modified in 2016);  ∙ ∙ in the Antoine‑Lacassagne Centre in Nice (new equipment installed in 2016); ∙ ∙ in the Archade Centre in Caen, François-Baclesse Centre (commissioned in 2018). According to its advocates, hadron therapy with carbon nuclei is more suited to the treatment of the most radiation-resistant tumours and could result in several hundred additional cancer cases being cured per year. The claimed biological advantage is purportedly due to the very high ionisation of these particles at the end of their path, combined with a lesser effect on the tissues they pass through before reaching the target volume. 2.2  ̶  Technical rules applicable to external‑beam radiotherapy installations The devices must be installed in rooms specially designed to guarantee radiation protection of the staff, turning them into veritable bunkers (wall thickness can vary from 1 m to 2.5 m of ordinary concrete). A radiotherapy installation comprises a treatment room including a technical area containing the treatment device, a control station outside the room and, for some accelerators, auxiliary technical premises. The protection of the premises, in particular the treatment room, must be determined in order to respect the annual exposure limits for the workers and/or the public around the premises. A specific study must be carried out for each installation by the machine supplier, together with the medical physicist and the Radiation Protection Expert-Officer (RPE-O). This study defines the thicknesses and nature of the various protections required, which are determined according to the conditions of use of the device, the characteristics of the radiation beam and the use of the adjacent rooms, including those vertically above and below the treatment room. This study should be included in the file presented to support the application for a license to use a radiotherapy installation, examined by ASN. In addition, a set of safety systems informs the operator of the machine operating status (exposure in progress or not) and switches off the beam in an emergency or if the door to the irradiation room is opened. 2.3  ̶  Radiation protection situation in external-beam radiotherapy The safety of radiotherapy treatments has been a priority area of ASN oversight since 2007. An inspection programme was defined for the 2016‑2019 period, and its broad lines were communicated to all the radiotherapy departments in early 2016. The inspections focus on the ability of the centres to deploy a risk management approach and, depending on the situation found by the inspectors, they also address the management of skills, the implementation of new techniques or practices and the command of the equipment. ASN has continued its graded approach to inspection: ∙ ∙ by reducing, in the light of the progress made in the control of treatment safety, the average frequency of inspection, which since 2016 has been reduced to once every three years (instead of the previous two-yearly frequency); ∙ ∙ by maintaining a higher frequency for the centres showing weaknesses or risks, implemented in 2018 in particular in some centres having necessitated tightened inspections assisted by experts (Bourgogne Cancerology Institute in Dijon, Lucien‑Neuwirth Cancerology Institute in Saint‑Priest- en‑Jarez) and placing under tightened surveillance (case of the Private Radiotherapy Centre in Metz). ASN inspected 95 centres in 2017, representing 55% of the national total. In 2018, it inspected 79 centres, or 45% of the national total. In two years, about two-thirds of the French radiotherapy centres have been inspected. 2.3.1  –  Radiation protection of external-beam radiotherapy professionals When the radiotherapy facilities are correctly designed, the radiation risks for the medical staff are limited due to the protection provided by the walls of the irradiation room. The results of the inspections carried out in 2018 reveal no major problems in this sector: ∙ ∙ The effective designation of Radiation Protection Expert- Officers (RPE-O) was confirmed in the majority of the centres inspected. ∙ ∙ The radiation protection technical controls were carried out in slightly more than 80% of the centres inspected. 2.3.2  –  Radiation protection of radiotherapy patients The assessment of the radiation protection of radiotherapy patients is based on the inspections focusing on implementation of the treatment quality and safety management system, made compulsory by ASN resolution 2008-DC-0103 of 1 July 2008. Since 2016, these inspections have included verifications of the adequacy of the human resources, and in particular the presence of the medical physicist and internal organisation procedures for tracking and analysing adverse events (or malfunctions) recorded by the radiotherapy centres. The presence of a medical physicist during the treatments was confirmed in almost 90% of the inspected centres. A medical physics organisation plan is also available in about 90% of the centres. The assessment shows that the detection of adverse events, their reporting (internally or to ASN) and their recording are deemed satisfactory on the whole. In contrast, the analysis of these adverse events is only satisfactory on the whole in 64% of the inspected centres: ∙ ∙ The analysis of the causes of events is still too succinct, often not going beyond the immediate causes. ∙ ∙ Similarly, the analyses of recurrent events are still poorly developed, even though they should constitute alert signals for the centre. The improvement in practices through experience feedback and the assessment of the effectiveness of the corrective actions were deemed satisfactory in only 27% of the centres inspected, a decrease of 10% compared to 2017. Although the majority of these procedures involve representatives of all the medical professionals who contribute to the treatment process, some of the personnel do not involve themselves, especially the physicians, which reduces the effectiveness of the procedures. In order to achieve real continued improvement in treatment quality and safety, further progress must be made in the monitoring and evaluation of the corrective actions put in place, in the involvement of all the personnel and in the utilisation of the experience feedback to assess and enrich the prospective risk analysis, required by the abovementioned ASN resolution 2008-DC-0103 of 1 July 2008. ASN report on the state of nuclear safety and radiation protection in France in 2018  209 07 – MEDICAL USES OF IONISING RADIATION 07