Associations antifongiques dans les infections fongiques invasives

International audienceInvasive fungal infections (candidiasis, aspergillosis and cryptococcosis) are major complications in immunocompromised patients and account for high morbidity and mortality. Guidelines on first-line therapy of invasive fungal infections are based on randomised clinical trials or experts’ guidelines and include essentially single antifungal therapies, except for cryptococcosis. However, the severe prognosis of these infections raises the interest of antifungal associations, in first line or second-line therapy, and many experimental data have been published on this issue. In humans, amphotericin B plus flucytosine combination therapy in cryptococcal meningitis has been largely validated, especially in HIV-infected patients. Also, a few studies demonstrated that the combination of fluconazole plus amphotericin B in candidiasis is not antagonistic and that caspofungin plus polyene or caspofungin plus azole combinations may be beneficial in invasive aspergillosis. Randomised studies are necessary to confirm these data. A study assessing anidulafungin plus voriconazole association in aspergillosis is oncoming.Les mycoses invasives (candidoses, aspergilloses et cryptococcoses) sont des complications infectieuses fréquentes d’une immunodépression, responsables d’une importante morbimortalité. Leur traitement de première ligne bénéficie de recommandations thérapeutiques qui sont basées selon les pathologies sur des essais randomisées ou sur des avis d’experts, et sont constituées essentiellement de monothérapies antifongiques, sauf pour la cryptococcose. Mais la sévérité de ces infections et l’existence de nombreux travaux expérimentaux et cliniques sur le sujet soulèvent la question de l’apport des bithérapies antifongiques, en traitement d’attaque ou de seconde ligne. Dans la cryptococcose neuroméningée, l’association amphotéricine B plus flucytosine a été bien validée dans des études randomisées, notamment chez les patients séropositifs pour le VIH. Dans les candidémies, des études démontrent l’absence d’antagonisme de l’association fluconazole plus amphotéricine B. Dans l’aspergillose, de rares études cliniques suggèrent, malgré des limites méthodologiques, un bénéfice des associations caspofungine plus polyène ou caspofungine plus azolé. Mais des études randomisées sont encore nécessaires pour démontrer le bénéfice de ces dernières associations. Une étude évaluant l’association anidulafungine plus voriconazole dans le traitement des aspergilloses invasives devrait débuter prochainement

Musical instruments for the measurement of autism sensory disorders

International audienceThe analysis of sensory disorders in children with autism is a long process based on the observation of children in a specific environment. It cannot be treated frequently and monitoring the evolution of sensory disorders is either impossible or limited to a period of more than one year. The objective of our study is to define and then use dedicated musical instruments to perceive the intensity of children's responses to different stimuli in order to measure their sensory disorders

Performance of ADONIS-LYNX system for burn-up measurement applications at AREVA NC la Hague reprocessing plant

Conference of 2013 3rd International Conference on Advancements in Nuclear Instrumentation, Measurement Methods and Their Applications, ANIMMA 2013 ; Conference Date: 23 June 2013 Through 27 June 2013; Conference Code:102802International audienceThis work deals with the last measurement campaign done at the AREVA NC La Hague reprocessing plant with the new industrial ADONIS system called ADONIS LYNX. In this paper we briefly explain the ADONIS bimodal Kalman smoother. Next, we present the experimental set-up as well as the industrial approach for the ADONIS system. Results from measurement campaign are then discussed. Some ways of improvement are also explained

IGRT kV-imaging dose MC calculations validated in anthropomorphic phantoms using OSL

International audiencePurpose or Objective: While in-room Magnetic Resonance Imaging starts becoming part of radiotherapy (RT) treatments, the use of X-ray imaging equipment in Image-Guided RT (IGRT) is still growing and with it the need to evaluate the additional dose-to-organs it delivers. This study aims atverifying the accuracy of Monte Carlo (MC) calculation of the patient dose-to-organs delivered by four commercially available kV imaging systems: the XVI CBCT (Elekta), the OBI CBCT (Varian), the ExacTrac 2D-kV system (Brainlab) and the 2D-kV CyberKnife imaging system (Accuray). Simulations were validated against OSL measurements in the pediatric anthropomorphic phantom Grant (CIRS, ATOM) performed in three different clinical sites.Material and Methods: Each of the four kV-imaging systems was modeled as a Virtual Source Model (VSM) using the Penelope MC code. Such models were validated as part of a previous study using ionization chambers in water phantoms [G. Boissonnat et al., ESTRO 2017 Vienna]. In a second step, CT images of the phantom Grant were used to generate a voxelized phantom by converting the HU value of each voxel into the appropriate biological tissue (chemical composition and density). Then for each system, photons produced by the corresponding VSM were propagated in the voxelized phantom in order to obtain the 3D relative absorbed dose-to-medium map for three localizations (head, thorax and pelvis). MC-calculateddoses were calibrated in amplitude using the ratio between the air kerma measured with an ionization chamber at the isocenter and the corresponding simulated value. After calibrating OSLs in air kerma at every beam quality, OSL measurements were performed in the anthropomorphic phantom at three localizations (head and neck, thorax and pelvis). After verifying that beam quality inside the phantom was impacting OSL corrections factors of less than 5%, they were neglecting. Therefore measured air kerma values were converted into absorbed dose-in-medium values using the incoming beam quality before being compared to simulated dose values.Results: MC calculations were performed in 2 hours on a cluster of 40 CPUs with a MC uncertainty better than 5% in 1mm3 voxels. The current study highlights the possibility to reproduce absolute dose measurements using VSM-driven MC simulations with an overall agreement better than 20 % (inside the irradiation field) for all four kV imaging systems and for the three anatomical localizations as presented in Table 1.Conclusion: This study demonstrates that MC calculations based on VSMs allow obtaining reliable absolute doses for kV imaging protocols in a reasonable computing time. All these developments are currently integrated into a dedicated software for imaging dose prediction, which will also include the Tomotherapy MVCT imaging system [V. Passal et al., MCMA 2017 Napoli].This software will enable to study the magnitude of additional doses delivered by in-room X-Ray imaging positioning units during the course of a complete RT treatment

20F Power Measurement for Generation IV Sodium Fast Reactors

International audienceThe Phénix nuclear power plant has been a French Sodium Fast Reactor (SFR) prototype producing electrical power between 1973 and 2010. The power was monitored using ex-core neutron measurements. This kind of measurement instantly estimates the power but needs to be often calibrated with the heat balance thermodynamic measurement. Large safety and security margins have then been set not to derive above the nominal operating point. It is important for future SFR to reduce this margin and working closer to the nominal operating point. This work deals with the use of delayed gamma to measure the power. The main activation product contained in the primary sodium coolant is the 24Na which is not convenient for neutron flux measurement due to its long decay period. The experimental study done at the Phénix reactor shows that the use of 20F as power tagging agent gives a fast and accurate power measurement closed to the thermal balance measurement thanks to its high energy photon emission (1.634 MeV) and its short decay period (11 s)

Delayed gamma power measurement for sodium-cooled fast reactors

Previous works on pressurized water reactors show that the nitrogen 16 activation product can be used to measure thermal power. Power monitoring using a more stable indicator than ex-core neutron measurements is required for operational sodium-cooled fast reactors, in order to improve their economic efficiency at the nominal operating point. The fluorine 20 and neon 23 produced by (n,α) and (n,p) capture in the sodium coolant have this type of convenient characteristic, suitable for power measurements with low build-up effects and a potentially limited temperature, flow rate, burn-up and breeding dependence. This method was tested for the first time during the final tests program of the French Phénix sodium-cooled fast reactor at CEA Marcoule, using the ADONIS gamma pulse analyzer. Despite a non-optimal experimental configuration for this application, the delayed gamma power measurement was pre-validated, and found to provide promising results