Introduction In Vivo Dosimetry (IVD) is mandatory in France for every "technically measurable" beam, since 2008 (criterion No. 15 of National Cancer Institute, for the practice of external radiotherapy). IVD was historically based on punctual measurement techniques adapted to conventional radiotherapy. The applicability of this method has greatly decreased with the dissemination of modulated radiotherapy techniques (IMRT, VMAT). The majority of French radiotherapy centers practice these advanced techniques (nearly 70% of them in 2013 [ [1] Observatoire national de la radiothérapie, situation fin 2013 et évolution depuis 2009 – INCA – Mai 2015. Google Scholar ]), for sometimes 100% of the treatments. So, the proportion of "non-technically measurable" beams grows very rapidly and new solutions must be considered to ensure a satisfactory level of treatments control. From this statement, resulting from the practices observed during inspections, Nuclear Safety Authority (ASN) wished to know what IVD solutions - especially those called "transit" based on the use of the portal imaging device (EPID) – are available or in development, the technical and organizational constraints of the "transit" IVD and its relations with other types of controls. Methods IRSN met providers of IVD solutions, or comparable control systems, and visited radiotherapy departments experienced in the field of transit IVD. The Medical Physicists representatives (SFPM) point of view has been collected, in continuation with the SFPM work of 2014 [ [2] Avis de la SFPM portant sur la dosimétrie in vivo dite " de transit " en radiothérapie externe – 23 décembre 2014. Google Scholar ]. Results This study focused on main "transit" IVD solutions currently proposed and nearly expected, as well as alternative or complementary solutions such as the analysis and monitoring of the LINAC parameters. Interviews with medical physicists revealed that IVD is part of an overall process of dose verification and cannot replace the controls performed without the patient. The definition of the intervention criteria or validation of DIV results, the identification of dose gap origin of and the interpretation of the results are the main mentioned difficulties, as well as the ergonomics of the devices, the tools of monitoring and analysis, the accessibility of data and the need for consistent human resources. The teams' expectations with respect to IVD, and therefore the requirements and resources allocated, can be on one hand a simple wish of regulatory compliance or, on the other hand, to use IVD as an adaptive radiotherapy tool . . Conclusions The offer of IVD solutions in recent radiotherapy techniques is progressing. The EPID-based IVD is the most widely used but, routinely, is often confined to conventional techniques. The exploitation and interpretability of the results is the main difficulty encountered by the teams, leading them to develop a treatment verification strategy in which the IVD is a one part of dose control and not the ultimate and global solution.

The examples and clinical cases presented in this section are not intended to be considered as absolute models in terms of image quality or device parameter settings. They must initiate an individual analysis according to CT parameters and image quality. Nevertheless, they present practically different CT levels, which can be used according to the clinical context and the type of device. (C) 2018 Elsevier Masson SAS. All rights reserved.

Once the imaging examination is justified by the clinical context, given the low doses of ionizing radiation delivered by nuclear imaging, the quality of the medical diagnosis always takes precedence over dosimetric considerations. Corollary to this assertion, the voluntary alteration of the image quality and therefore of the quality of the diagnosis on the basis of radiation protection considerations alone constitutes medical malpractice. (C) 2018 Elsevier Masson SAS. All rights reserved.

Les niveaux de référence diagnostiques (NRD), introduits par la CIPR au début des années 1990, sont destinés à aider les professionnels de l’imagerie médicale à évaluer leurs pratiques et à optimiser les doses délivrées aux patients. Établis en France depuis 2004, initialement sur la base des recommandations européennes, les NRD sont mis à jour régulièrement par les autorités. Ces dernières s’appuient sur les résultats d’analyses nationales conduites par l’Institut de radioprotection et de sûreté nucléaire (IRSN), à qui a été confiée la responsabilité du recueil et de l’analyse des données de doses délivrées dans les établissements d’imagerie. Après cinq rapports d’analyse de l’IRSN, une révision de la réglementation en 2011, et à l’aube d’une nouvelle mise à jour en 2018, la France dispose d’un recul important sur les forces et les faiblesses du dispositif instauré en 2004. L’appropriation des NRD par les professionnels et l’adéquation des NRD avec la pratique clinique sont indiscutablement les deux pierres d’achoppement auxquelles sociétés savantes et institutions sont confrontées. Ce travail propose donc de dresser un bilan des réussites et des lacunes du dispositif des NRD français, et de présenter ses prochaines évolutions qui vont fournir aux professionnels un outil amélioré et actualisé pour les aider à optimiser les doses délivrées aux patients.

Artifacts result from discrepancy between the estimated density values coming from the reconstructed CT image and the real value. They may come from many reasons (patient, device, algorithm, RX physical) and lead to deterioration of image quality and bad attenuation correction for SPECT or PET. (C) 2018 Elsevier Masson SAS. All rights reserved.

Iodinated Contrast Agent (ICA) may be used in nuclear medicine for level 3 and 4 CT level. The use of ICA in SPECT/CT or PET/CT is driven, for each patient, by the clinical context, the benefit/risk ratio and the availability and the date of the previous injected CT. The improvement in diagnostic performance of the exam is the main goal of the ICA injection during a hybrid NM procedure. (C) 2018 Elsevier Masson SAS. All rights reserved.

L’administration de PCI en médecine nucléaire se conçoit dans le cadre de pratiques de TDM de niveaux 3 et 4. L’utilisation des PCI en médecine nucléaire dans le cadre des examens de TEMP/TDM ou TEP/TDM est soumise à l’évaluation pour chaque patient du rapport bénéfice–risque, tenant compte des examens qui ont déjà eu lieu, de leurs résultats et de leur disponibilité/accessibilité le jour de l’examen de MN. Les bénéfices attendus d’une injection de PCI sont une amélioration globale des performances diagnostiques de l’examen.

The original version of this article, published on 01 August 2018, unfortunately contained two mistakes.

Les exemples et les cas cliniques présentés dans cette partie n’ont pas vocation à être considérés comme des modèles absolus en termes de qualité image ou de paramétrage des appareils. Les exemples doivent contribuer à initier une réflexion individuelle concernant le paramétrage du scanner en fonction de la situation clinique, du niveau de scanner que l’on souhaite réaliser et de l’appareillage dont on dispose. Ils permettent de présenter de manière concrète à partir d’images de sélection, des exemples des différents niveaux de scanner envisageables dans une situation donnée.

Quality and regulatory controls in hybrid nuclear medicine, layout and installations constraints, Diagnostic Reference values and regulatory and mandatory information in the medical report are presented in that part. (C) 2018 Elsevier Masson SAS. All rights reserved.

Many parameters can affect the patient's dose and the CT image quality. It is therefore essential, in order to optimize the patient's dosimetry, to know the influence of these parameters as well as their link with the dose modulation tools. (C) 2018 Elsevier Masson SAS. All rights reserved.

Nuclear medicine hybrid imaging is a technological evolution of gamma camera scintigraphy or positron emission tomography imaging methods that are now often coupled with an anatomical imaging device, essentially a CT scanner. Following a large demand from the nuclear physicians themselves, but also from the French Nuclear Safety Authority, this guide is intended for the entire nuclear medicine community to integrate both the aspects of radiation protection related to coupled CT and those related to the quality of the CT images according to the clinical context. (C) 2018 Elsevier Masson SAS. All rights reserved.

Les artefacts résultent d’une discordance entre les valeurs de densité estimées de l’image reconstruite et les valeurs réelles d’atténuation. Ils peuvent provenir d’une multitude de sources différentes (patient, matériel, algorithme, physique du rayonnement X) et entraîner une dégradation significative de la qualité des images TDM avec le risque de fausser aussi la correction d’atténuation en TEP ou TEMP.

The examples and clinical cases presented in this section are not intended to be considered as absolute models in terms of image quality or device parameter settings. They must initiate an individual analysis according to CT parameters and image quality. Nevertheless, they present practically different CT levels, which can be used according to the clinical context and the type of device. (C) 2018 Elsevier Masson SAS. All rights reserved.

De nombreux paramètres peuvent influer la dose au patient et la qualité d’image scanographique. Il est donc essentiel pour chercher à optimiser la dosimétrie du patient de connaître l’influence de ces paramètres ainsi que leur lien avec les outils modulation de dose.

The examples and clinical cases presented in this section are not intended to be considered as absolute models in terms of image quality or device parameter settings. They must initiate an individual analysis according to CT parameters and image quality. Nevertheless, they present practically different CT levels, which can be used according to the clinical context and the type of device. (C) 2018 Elsevier Masson SAS. All rights reserved.

Introduction A national retrospective survey on patient doses was performed by the French Society of Medical physicists to assess reference levels (RLs) in interventional radiology as required by the European Directive 2013/59/Euratom. Methods Fifteen interventional procedures in neuroradiology, vascular radiology and osteoarticular procedures were analysed. Kerma-area-product (KAP), fluoroscopy time (FT), reference air kerma and number of images were recorded for 10–30 patients per procedure. RLs were calculated as the 3rd quartiles of the distributions. Results Results on 4500 procedures from 36 departments confirmed the large variability in patient dose for the same procedure. RLs were proposed for the four dosimetric estimators and the fifteen procedures. RLs in terms of KAP and FT were 90 Gy cm2 and 11 min for cerebral angiography, 35 Gy cm2 and 16 min for biliary drainage, 70 Gy cm2 and 6 min for lower limbs arteriography and 70 Gy cm2 and 11 min for vertebroplasty. For these four procedures, RLs were defined according to the complexity of the procedure. For all the procedures, the results were lower than most of those already published. Conclusions This study reports RLs in interventional radiology, based on a national survey. Continual evolution of practices and technologies requires regular updates of RLs.