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International audience; Purpose The European Network of Biological and Physical Retrospective Dosimetry ‘RENEB’ has contributed to European radiation emergency preparedness. To give homogeneous dose estimation results, RENEB partners must harmonize their processes. Materials and methods A first inter-comparison focused on biological and physical dosimetry was used to detect the outliers in terms of dose estimation. Subsequently, trainings were organized to improve both tools dose estimation. A second inter-comparison was performed to validate training efficiency. Simultaneously, based on ISO standards, a QAandQM manual on all dosimetry assays was produced which states a common basis and harmonized procedures for each assay. The evaluation of the agreement of RENEB partners to follow the QAandQM manual was performed through a questionnaire. The integration of new members into the network was carried out in the same way, whatever the assays. Results The training courses on biological and physical dosimetry were judged to be successful because most of the RENEB members’ dose estimates improved in the second inter-comparison. The QAandQM manual describes the consensus for the minimum requirements and the performance criteria for both dosimetry assays. The questionnaire revealed that the whole network capacity currently can manage between 15 and 3800 samples once. Conclusion The methodology used to harmonize all dosimetry practice within the network RENEB was highly successful. The network is operational to manage a mass casualty radiation accident for immediate dose assessment. © 2016 The Author(s). Published by Informa UK Limited, trading as Taylor and Francis Group.

International audience; Purpose: The RENEB accident exercise was carried out in order to train the RENEB participants in coordinating and managing potentially large data sets that would be generated in case of a major radiological event. Materials and methods: Each participant was offered the possibility to activate the network by sending an alerting email about a simulated radiation emergency. The same participant had to collect, compile and report capacity, triage categorization and exposure scenario results obtained from all other participants. The exercise was performed over 27 weeks and involved the network consisting of 28 institutes: 21 RENEB members, four candidates and three non-RENEB partners. Results: The duration of a single exercise never exceeded 10 days, while the response from the assisting laboratories never came later than within half a day. During each week of the exercise, around 4500 samples were reported by all service laboratories (SL) to be examined and 54 scenarios were coherently estimated by all laboratories (the standard deviation from the mean of all SL answers for a given scenario category and a set of data was not larger than 3 patient codes). Conclusions: Each participant received training in both the role of a reference laboratory (activating the network) and of a service laboratory (responding to an activation request). The procedures in the case of radiological event were successfully established and tested. © 2016 The Author(s). Published by Informa UK Limited, trading as Taylor & Francis Group.

International audience; Purpose In the EC-funded project RENEB (Realizing the European Network in Biodosimetry), physical methods applied to fortuitous dosimetric materials are used to complement biological dosimetry, to increase dose assessment capacity for large-scale radiation/nuclear accidents. This paper describes the work performed to implement Optically Stimulated Luminescence (OSL) and Electron Paramagnetic Resonance (EPR) dosimetry techniques. Materials and methods OSL is applied to electronic components and EPR to touch-screen glass from mobile phones. To implement these new approaches, several blind tests and inter-laboratory comparisons (ILC) were organized for each assay. Results OSL systems have shown good performances. EPR systems also show good performance in controlled conditions, but ILC have also demonstrated that post-irradiation exposure to sunlight increases the complexity of the EPR signal analysis. Conclusions Physically-based dosimetry techniques present high capacity, new possibilities for accident dosimetry, especially in the case of large-scale events. Some of the techniques applied can be considered as operational (e.g. OSL on Surface Mounting Devices [SMD]) and provide a large increase of measurement capacity for existing networks. Other techniques and devices currently undergoing validation or development in Europe could lead to considerable increases in the capacity of the RENEB accident dosimetry network. © 2016 The Author(s). Published by Informa UK Limited, trading as Taylor and Francis Group.

International audience; Purpose The use of small photon fields is now an established practice in stereotactic radiosurgery and radiotherapy. However, due to a lack of lateral electron equilibrium and high dose gradients, it is difficult to accurately measure the dosimetric quantities required for the commissioning of such systems. Moreover, there is still no metrological dosimetric reference for this kind of beam today. In this context, the first objective of this work was to determine and to compare small fields output factors (OF) measured with different types of active detectors and passive dosimeters for three types of facilities a CyberKnife® system, a dedicated medical linear accelerator (Novalis) equipped with m3 microMLC and circular cones, and an adaptive medical linear accelerator (Clinac 2100) equipped with an additional m3 microMLC. The second one was to determine the kQclin,Q msrfclin,fmsr correction factors introduced in a recently proposed small field dosimetry formalism for different active detectors. Methods Small field sizes were defined either by microMLC down to 6 × 6 mm2 or by circular cones down to 4 mm in diameter. OF measurements were performed with several commercially available active detectors dedicated to measurements in small fields (high resolution diodes IBA SFD, Sun Nuclear EDGE, PTW 60016, PTW 60017; ionizing chambers PTW 31014 PinPoint chamber, PTW 31018 microLion liquid chamber, and PTW 60003 natural diamond). Two types of passive dosimeters were used LiF microcubes and EBT2 radiochromic films. Results Significant differences between the results obtained by several dosimetric systems were observed, particularly for the smallest field size for which the difference in the measured OF reaches more than 20%. For passive dosimeters, an excellent agreement was observed (better than 2%) between EBT2 and LiF microcubes for all OF measurements. Moreover, it has been shown that these passive dosimeters do not require correction factors and can then be used as reference dosimeters. Correction factors for the active detectors have then been determined from the mean experimental OF measured by the passive dosimeters. Conclusions Four sets of correction factors needed to apply the new small field dosimetry formalism are provided for several active detectors. A protocol for small photon beams OF determination based on passive dosimeters measurements has been recently proposed to French radiotherapy treatment centers. © 2013 American Association of Physicists in Medicine.

N° d'ordre : DU 1739, EDSF : 528; The aim of this work was to date lava flows from the Chaîne des Puys (Massif Central, France) which were chronologically situated during the period of the Laschamp paleomagnetic event (30-50 ka). The methods used were thermoluminescence and optically stimulated luminescence applied to quartz grains and quartz pebbles extracted from sediments baked by the lava flows. These minerals often emit luminescence signals exhibiting erratic behaviour. Thus, their palaeodoses were tentatively determined by various methods to select those which were most likely to yield reliable results. These intercomparisons highlighted a dispersion of results beyond what could be expected from the uncertainties usually associated with each measurement. In the majority of cases, these observations forced us to propose a relatively wide interval in which the most probable age of the sample is included.; L'objectif de ce travail était de dater des coulées volcaniques de la Chaîne des Puys (Massif Central, France) situées chronologiquement dans la période de l'événement paléomagnétique de Laschamp (30-50 ka). Les méthodes utilisées étaient la thermoluminescence et la luminescence stimulée optiquement appliquées à des grains de quartz et à des galets quartzeux extraits de sédiments cuits par ces coulées. Ces minéraux émettent des signaux de luminescence dont le comportement est souvent irrégulier. Leur paléodose a donc été déterminée par différentes méthodes pour choisir celles qui seraient les plus appropriées à l'obtention de résultats fiables. Ces intercomparaisons ont mis en évidence une dispersion des résultats supérieure à ce qui pouvait être attendu au regard des incertitudes habituellement associées à chacune d'entre elles. Dans la plupart des cas, ces observations ont conduit à proposer un intervalle assez large dans lequel est compris l'âge probable de l'échantillon.

Thermoluminescence, poster présenté par C. Bassinet

présenté par C. Bassinet