ASN Report 2020

Nuclear medicine enables functional images to be produced. It is therefore complementary to the purely morphological images obtained using the other imaging techniques. In order to make it easier to merge functional and morphological images, hybrid appliances have been developed: Positron-Emitting Tomography (PET) scanners are now systematically coupled with a CT scanner (PET-CT) and gamma-cameras can also be equipped with a CT scanner (SPECT-CT). The installation of semi-conductor cameras (Cadmium Zinc Telluride – CZT), which have very high detection sensitivity, is continuing to develop, particularly in health care centres performing a large number of examinations of the myocardial function. These cameras effectively provide for faster and more comfortable scintigraphic imaging and give a more reliable diagnosis. Research in this area is continuing with the installation in 2020 of two whole body gamma-cameras allowing spatial viewing of the entire body. According to the survey conducted with the nuclear medicine units in 2018, the installed pool of SPECT and CZT cameras comprises: ∙ 423 SPECT cameras, of which 70% are coupled to a computed tomography (CT) scanner, accounting for 924,000 procedures per year; ∙ 51 semi-conductor cameras (CZT), of which 7 are coupled to a CT scanner, accounting for 125,000 procedures per year. The installed base of PET cameras comprised: ∙ 158 PET cameras, all coupled to a CT scanner, accounting for 486,000 procedures per year; ∙ 4 PET cameras coupled to an MRI scanner, performing some 2,000 procedures per year. 4.1.2 In vitro diagnosis This is a medical biology technique that enables certain com­ pounds contained in biological fluid samples taken from the patient, such as hormones or tumoral markers, to be assayed, without administering radionuclides to the patient. This technique uses assaying methods based on immunological reactions (reactions between antigens and antibodies marked with iodine-125), hence the name Radio Immunology Assay or radioimmunoassay – RIA). The activities contained in the analysis kits designed for a series of assays do not exceed a few thousand becquerels. Radioimmunology is challenged by techniques that do not use radioactivity, such as immuno-enzymology and chemiluminescence. A few techniques use other radionuclides such as tritium or carbon-14. Here again the activity levels involved are of the order of the kilobecquerel. 4.1.3 Internal targeted radiotherapy Used for therapeutic purposes, the aim of the administered RPDs is to deliver a high dose of ionising radiation to a target organ for curative or palliative purposes. Two areas of thera­ peutic application of nuclear medicine can be identified: oncology and non-oncological conditions (treatment of forms of hyperthyroidism, synoviorthesis). Several types of cancer treatment can be identified: ∙ treatments administered by nonspecific systemic route, such as thyroid cancer by iodine-131, non-Hodgkin lymphoma by monoclonal antibodies marked with yttrium-90, prostate cancer which has spread to the bones by radium-223, treatment of neuroendocrine or prostate cancers by molecules marked with lutetium-177 (lutetium therapy); ∙ treatments administered by selective systemic route (treatment of liver cancers by administering microspheres marked with yttrium-90 through a catheter placed in an artery). Some treatments require patients to be hospitalised for several days in specially fitted-out rooms in the nuclear medicine unit to ensure the radiation protection of the personnel, of people visiting the patients and of the environment. The radiological protection of these rooms is adapted to the nature of the radiation emitted by the radionuclides, and the contaminated urine of the patients is collected in tanks. This is particularly the case with the post- surgical treatment of certain thyroid cancers. The treatments are performed by administering iodine-131 with activities varying from 1.1 GBq to 5.5 GBq. For therapeutic purposes, there are 165 ITR hospital rooms distributed over 45 nuclear medicine units (see Graph 9). Other treatments can be administered on an out-patient basis. Examples include administering iodine-131 to treat hyperthyroidism, strontium-89 or samarium-153 for painful GRAPH 9 Breakdown, by ASN regional division, of the nuclear medicine facilities licensed by ASN, the number of hospitalisation rooms dedicated to internal targeted radiotherapy and the number of inspections performed in these facilities by ASN in 2020 Strasbourg Division Paris Division Orléans Division Nantes Division Marseille Division Lyon Division Lille Division Dijon Division Châlons-en- Champagne Division Caen Division Bordeaux Division 0 10 20 30 40 50 Facilities ITR rooms Inspections performed 224 ASN Report on the state of nuclear safety and radiation protection in France in 2020 07 – MEDICAL USES OF IONISING RADIATION