ASN Report 2020

This therapeutic technique chiefly uses three specific types of equipment, such as: ∙ Gamma Knife®, which uses more than 190 cobalt-60 sources. It acts like a veritable scalpel over an extremely precise and delimited zone (5 units in service); ∙ robotic stereotactic radiotherapy; CyberKnife® is a miniaturised linear accelerator mounted on a robotic arm (19 units in service); ∙ multi-purpose linear accelerators equipped with additional collimation means (mini-collimators, localisers) that can produce mini-beams. 2.1.4 Radiotherapy using a linear accelerator coupled to a magnetic resonance imaging system A first linear accelerator coupled to a Magnetic Resonance Imaging (MRI) system was installed in the Paoli-Calmette Institute in Marseille in 2018. The combining of these two technologies (linear accelerator and MRI) has raised new questions regarding its clinical use, in terms not only of measurement and calculation of the dose delivered to the patient but also of the quality control of the complete machine concerning both the accelerator and the imaging device. Following an expert assessment by the IRSN, ASN authorised entry into service of this new technique at the end of 2018. In 2019, two other centres were licensed to possess and use this type of machine, namely the Georges François Leclerc Centre in Dijon and the Montpellier Cancer Institute (ICM) – Val d’Aurelle in Montpellier. No new devices of this type were installed in 2020. 2.1.5 Contact radiotherapy Contact therapy or contact radiotherapy is an external-beam radiotherapy technique. The treatments are delivered by an X-ray generator using low-energy beams varying from 50 to 200 kilovolts (kV). These low-energy beams are suitable for the treatment of skin cancers because the dose they deliver decreases rapidly with depth. 2.1.6 Intraoperative radiotherapy Intraoperative radiotherapy combines surgery and radiotherapy, with the radiation dose being delivered in the operating theatre to the tumour bed during surgical intervention. This technique is used primarily for treating small cancers of the breast. In April 2016, the French National Authority for Health (HAS) published the results of the assessment of this practice and concluded that the conditions necessary to propose coverage by the state health insurance scheme were not satisfied at the time. It considered that the clinical and medico-economic studies had to be continued in order to acquire clinical data over the longer term. After four years, development of this technique has remained limited and its assessment is continuing. New intraoperative radiotherapy devices covered by the CE marking have been put on the market. The benefits of using these devices, linked to optimised irradiation of the targeted tumour while preserving the surrounding healthy tissue, and their deployment in France, shall be assessed. Devices of this type are to be examined by the Committee for analysing new practices or techniques using ionising radiation (Canpri) in 2021. 2.1.7 Hadron therapy Hadron therapy is a treatment technique based on the use of beams of charged particles – protons and carbon nuclei – whose particular physical properties ensure highly localised dose distribution during treatment. Compared with existing techniques, the dose delivered around the tumour to irradiate is lower, therefore the volume of healthy tissue irradiated is drastically reduced. Hadron therapy allows the specific treatment of certain tumours. In June 2016, the INCa published a report on proton therapy treatment indications and possibilities. Hadron therapy with protons is currently used in three centres in France: ∙ the Curie Institute of Orsay (equipment modified in 2016); ∙ the Antoine‑Lacassagne Centre in Nice (new equipment instal­ led in 2016); ∙ the François-Baclesse Centre (ARCHADE project) in Caen (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 each year. The claimed biological advantage is purportedly due to the very high ionisation of these particles GRAPH 5 Breakdown, by ASN regional division, of the number of centres and external-beam radiotherapy accelerators inspected and the number of new licenses or license renewals issued by ASN in 2020 0 10 20 30 40 50 60 70 80 90 100 Strasbourg Division Paris Division Orléans Division Nantes Division Marseille Division Lyon Division Lille Division Dijon Division Châlons-en- Champagne Division Caen Division Bordeaux Division Licensed centres Accelerators Authorisations issued 214 ASN Report on the state of nuclear safety and radiation protection in France in 2020 07 – MEDICAL USES OF IONISING RADIATION