ASN Report 2018

∙ ∙ Improvements must be made however in the reinforced training for emergency situations. In about a third of the centres inspected, no simulated situation exercises were held (high activity source jammed, for example), or there is no procedure covering this situation. ASN considers that efforts must still be made to reinforce the radiation protection training of workers if a high activity source is possessed. 3.3.2  –  Radiation protection of patients As with external-beam radiotherapy, the radiation protection of brachytherapy patients is assessed from the inspections concerning the implementation of the treatment quality and safety management system. 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 treatment quality and safety management system The qualitative result of the inspections carried out in 2018 has shown that the majority of brachytherapy departments inspected have deployed the quality management system, with the support of the external-beam radiotherapy departments. They nevertheless present the same shortcomings with regard to the prospective risks analysis and no improvement has been seen in this area compared with 2017. The effectiveness of corrective actions put in place following adverse events is found to be insufficient in about 57% of the centres inspected in 2018, which leaves a large margin for improvement. The prior validation of HDR brachytherapy treatments is formalised in just 54% of the cases, which is still insufficient given the risks associated with the use of high-activity sources. Maintenance and quality controls – The majority of the centres have an inventory of the medical devices and a register for recording maintenance operations and quality controls. In the absence of an ANSM decision defining the baseline requirements for the quality controls of brachytherapy devices, the quality controls implemented result from the past practices and are based on the recommendations of the manufacturers or medical professionals. Maintenance of the HDR and PDR afterloaders is ensured by the manufacturers. More specifically, the manufacturers perform the afterloader operating verifications when replacing the sources. The brachytherapy units rely on these verifications to guarantee correct operation of the devices. The source activity is verified at each delivery and source removal verifications are also carried out. Percentage of conformity of the facilities concerning the management of events giving rise to corrective actions in 2018 0% 10% 20% 30% 40% 50% 60% 70% 80% 90% 100% Culture and organisation of reporting Analysis, definition of corrective actions, capitalisation Existence of an HDR validation procedure and traceability Evaluation of the effectiveness of corrective actions Diagram 8 Events rated level 2 on the ASN‑SFRO scale One event was rated level 2 on the ASN‑SFRO scale in 2018. It involved an excessive dose during a treatment of keloid scars by HDR brachytherapy. The patient displayed necrosis and bleeding of the treated area and healing difficulties that were discovered late. This adverse effect was caused by a calculation error in the dosimetry step, which resulted in the treated area receiving twice the planned dose. Several factors were found to have caused this event, notably poor ergonomics of the treatment programming software and the fact that the medical staff were frequently interrupted when carrying out the tasks necessary for the preparation of this treatment. Further to an inspection, the centre was also asked to better formalise the requirements and responsibilities associated with the brachytherapy verifications and validations, to organise audits to test the robustness of the human verifications and to adapt the staff workloads in order to foster continuity and serenity in the performance of tasks associated with treatment safety. 214  ASN report on the state of nuclear safety and radiation protection in France in 2018 07 – MEDICAL USES OF IONISING RADIATION