ASN Report 2017

274 ASN report on the state of nuclear safety and radiation protection in France in 2017 Chapter 09  - Medical uses of ionising radiation 3.2.5 Intraoperative radiotherapy Intraoperative radiotherapy combines surgery and radiotherapy, which are carried out at the same time in an operating theatre. The dose of radiation is delivered to the tumour bed during surgical intervention. In March 2011, the French National Cancer Institute (INCa) launched a call for proposals to support the installation of intraoperative radiotherapy equipment for the treatment of breast cancer patients. One of the objectives of this call for proposals was to carry out a medico-economic assessment of radiotherapy treatments involving a small number of sessions compared with standard breast cancer treatments. Seven projects deploying an INTRABEAM ® accelerator producing X-rays with a voltage of 50 kV were selected and launched between 2011 and 2012. The French National Authority for Health (HAS) published the results of its assessment 6 in April 2016. According to the HAS, current knowledge is insufficient to demonstrate the benefits of intraoperative radiotherapy in the adjuvant treatment of breast cancer compared with standard external- beam radiotherapy. The HAS concludes that at present, the elements necessary to propose that it be covered by the health insurance scheme are not yet established and considers that the clinical and medico-economic studies must be continued in order to acquire clinical data over the longer term. At the end of this assessment, the HAS does however recommend continuing the assessment of intraoperative radiotherapy for clinical research purposes. 3.2.6 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 (Bragg’s peak). Compared with existing techniques, the dose delivered around the tumour to be irradiated is lower, therefore the volume of healthy tissue irradiated is drastically reduced. Hadron therapy allows the specific treatment of certain tumours. Hadron therapy with protons is currently used in two centres in France: ཛྷ ཛྷ the Curie Institute in Orsay (equipment modified in 2016): in March  2017, this centre treated its first patient using the Pencil-Beam Scanning (PBS) technique. This new technology enables the tumour to be scanned with the beam of protons and thus treat tumours of complex volumes ; ཛྷ ཛྷ and the Antoine Lacassagne Centre in Nice (new equipment installed in 2016). A third installation is being set up in the hadron therapy research and treatment centre (Archade project) in Caen and treatment of the first patient is planned for summer 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 6 . www.has-sante.fr/portail/jcms/c_2562276/fr/evaluation-de-la-radiotherapie- peroperatoire-rtpo-dans-le-cancer-du-sein 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. In June 2016, the INCa published a report on proton therapy treatment indications and possibilities. 3.2.7 Contact radiotherapy Contact therapy or contact radiotherapy is an external-beam radiotherapy technique. The treatments involve an X-ray generator delivering low-energy beams varying from 50 to 200 kV. These low-energy beams are suitable for the treatment of skin cancers because the dose they deliver decreases rapidly with depth. 3.3 Brachytherapy Brachytherapy allows specific or complementary treatment of cancerous tumours, particularly in the head and neck, the skin, the breast, the genitals and the bronchial tubes. This technique consists in implanting radionuclides, exclusively in the form of sealed sources, either in contact with or inside the solid tumours to be treated. The main radionuclides used in brachytherapy are iridium-192 and iodine-125. Brachytherapy techniques involve three types of applications. 3.3.1 Low Dose-Rate (LDR) brachytherapy ཛྷ ཛྷ delivering dose-rates of between 0.4 and 2 Gy/h; ཛྷ ཛྷ using iodine-125 sources in the form of seeds implanted permanently. These iodine-125 sources (seeds) are used to treat prostate cancers. The seeds - which are implanted permanently in the patient’s prostate gland - have unit activity levels of between 10 and 30 MBq, and as a treatment requires about one hundred seeds, this gives a total activity of 1 to 2 gigabecquerels (GBq). Intra-cranial treatment by proton therapy, in the isocentric gantry room (Proton therapy centre of the Curie Institute).