J. Barthe

Cea Leti, Grenoble, Rhône-Alpes, France

Are you J. Barthe?

Claim your profile

Publications (40)29.87 Total impact

  • B Habib · B Poumarede · F Tola · J Barthe
    [Show abstract] [Hide abstract]
    ABSTRACT: The aim of the present study is to demonstrate the potential of accelerated dose calculations, using the fast Monte Carlo (MC) code referred to as PENFAST, rather than the conventional MC code PENELOPE, without losing accuracy in the computed dose. For this purpose, experimental measurements of dose distributions in homogeneous and inhomogeneous phantoms were compared with simulated results using both PENELOPE and PENFAST. The simulations and experiments were performed using a Saturne 43 linac operated at 12 MV (photons), and at 18 MeV (electrons). Pre-calculated phase space files (PSFs) were used as input data to both the PENELOPE and PENFAST dose simulations. Since depth-dose and dose profile comparisons between simulations and measurements in water were found to be in good agreement (within +/-1% to 1 mm), the PSF calculation is considered to have been validated. In addition, measured dose distributions were compared to simulated results in a set of clinically relevant, inhomogeneous phantoms, consisting of lung and bone heterogeneities in a water tank. In general, the PENFAST results agree to within a 1% to 1 mm difference with those produced by PENELOPE, and to within a 2% to 2 mm difference with measured values. Our study thus provides a pre-clinical validation of the PENFAST code. It also demonstrates that PENFAST provides accurate results for both photon and electron beams, equivalent to those obtained with PENELOPE. CPU time comparisons between both MC codes show that PENFAST is generally about 9-21 times faster than PENELOPE.
    No preview · Article · Apr 2009 · Physica Medica
  • [Show abstract] [Hide abstract]
    ABSTRACT: This article proposes an innovative multichannel optically stimulated luminescence (OSL) dosemeter for on-line in vivo dose verification in radiation therapy. OSL fibre sensors incorporating small Al2O3:C fibre crystals (TLD500) have been tested with an X-ray generator. A reproducible readout procedure should reduce the fading-induced uncertainty (∼− 1% per decade). OSL readouts are temperature-dependent [∼0.3% K−1 when OSL stimulation is performed at the same temperature as irradiation; ∼0.16% K−1 after thermalisation (20°C)]. Sensor calibration and depth–dose measurements with electron beams have been performed with a Saturne 43 linear accelerator in reference conditions at CEA-LNHB (ionising radiation reference laboratory in France). Predosed OSL sensors show a good repeatability in multichannel operation and independence versus electron energy in the range (9, 18 MeV). The difference between absorbed doses measured by OSL and an ionisation chamber were within ±0.9% (for a dose of about 1 Gy) despite a sublinear calibration curve.
    No preview · Article · Sep 2008 · Radiation Protection Dosimetry
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: An innovative multichannel fibre-coupled Optically Stimulated Luminescence (OSL) dosimeter is proposed for on-line in vivo quality assurance in Radiation Therapy (RT). Small Al 2 O 3 :C fibre crystals (TLD 500) are used as OSL detectors, incorporated into a rugged, radiation-resistant and radiation-transparent OSL fibre sensor design. The temperature and fading dependences of OSL fibre sensors and stability vs cumulated dose have been tested with a X-ray generator. Predosed OSL sensors tested at Institut Gustave Roussy (IGR) show a good repeatability in multichannel operation. Sensor calibration and depth-dose measurements with electron beams have been performed with a Saturne 43 LINAC in reference conditions at CEA-LNHB (ionizing radiation reference laboratory in France). The difference between absorbed doses measured by OSL and an ionization chamber was within ± 0.9 % (for a dose of about 1 Gy) despite a sublinear dose response. Finally, a single calibration curve was used for all beams as energy independence vs electron energy was found in the range [9 MeV, 18 MeV]. Angular independence was found as well in the range [0°, 45°] when the OSL sensor is equipped with its bolus. KEYWORDS: Optically Stimulated Luminescence (OSL), Fibre optics, in vivo dosimetry, Radiation Therapy.
    Full-text · Article · Jan 2008
  • [Show abstract] [Hide abstract]
    ABSTRACT: The integrated project MAESTRO (Methods and Advanced Equipment for Simulation and Treatment in Radio-Oncology) under contract with the European Commission in life sciences FP6 (LSHC-CT-2004-503564), concerns innovative research to develop and validate in clinical conditions, advanced methods and equipment needed in cancer treatment for new modalities in high-conformal external radiotherapy using electrons, photons and protons beams of high energy.
    No preview · Article · Dec 2007 · Nuclear Instruments and Methods in Physics Research Section A Accelerators Spectrometers Detectors and Associated Equipment
  • Source
    Baptiste Blanpain · David Mercier · Jean Barthe
    [Show abstract] [Hide abstract]
    ABSTRACT: Une méthode de calcul de la dose déposée en radiothérapie est présentée. À partir de courbes de dose en milieu homogène, apprises par des réseaux de neurones, nous proposons une heuristique de reconstruction de la dose en milieu hétérogène, dans le cas d'une interface orthogonale au faisceau. Les premiers tests donnent une erreur maximale de 3%, qui rentre bien dans les marges de sécurité imposées par les protocoles de radiothérapie.
    Preview · Article · Oct 2007
  • [Show abstract] [Hide abstract]
    ABSTRACT: A multi-channel fibre optic OSL dosimeter system is developed by the CEA LIST for quality control in cancer radiation therapy, in the framework of the European Integrated Project MAESTRO.
    No preview · Article · Jan 2007 · Proceedings of SPIE - The International Society for Optical Engineering
  • J. Barthe · B. Chauvenet · J.-M. Bordy

    No preview · Article · Jan 2006 · Radioprotection
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Les codes de Monte Carlo deviennent un outil essentiel en physique de l'interaction rayonnement – matière, tant dans le domaine de la radioprotection que dans celui de la physique médicale, en particulier la radiothérapie. La possibilité d'y inclure une très grande partie de la physique de l'interaction élémentaire sous la forme de modèles numériques de plus en plus élaborés les rendent à la fois plus prédictifs, précis et fiables. Ils permettent en outre la détermination de grandeurs inaccessibles par l'expérience. Leur utilisation en métrologie des rayonnements ionisants a pris un réel essor ces dix dernières années avec l'arrivée d'ordinateurs plus puissants à un coût modéré. Néanmoins, l'importance des approximations numériques qui y sont faites et l'incertitude inhérente aux sections efficaces qui y sont utilisées, surtout à basses énergies, ne permettent pas d'atteindre la précision absolue requise en métrologie (inférieure ou de l'ordre du pour mille). On les utilise donc essentiellement pour calculer ou valider les coefficients de correction qui sont appliqués aux mesures expérimentales. Pour des raisons mathématiques évidentes, ces coefficients sont jusqu'à présent calculés avec de nombreuses hypothèses simplificatrices. L'utilisation des codes de Monte Carlo permet donc d'obtenir des valeurs correctives plus exactes ou inaccessibles par les méthodes traditionnelles. Nous présentons un certain nombre de résultats obtenus dans le cadre de la métrologie de la dose (influence des interstices de vide dans un calorimètre, influence des parois dans un dosimètre chimique, etc.) ainsi que dans celui de la métrologie de la radioactivité (efficacité et spectres des dépôts en énergie dans un détecteur, spectres en énergie de sources épaisses, etc.).
    Full-text · Conference Paper · Oct 2003
  • Source
    Jean Barthe
    [Show abstract] [Hide abstract]
    ABSTRACT: This paper attempts to give an idea on the state of the art in electronic solid state dosimetry, including devices mainly based on semiconductors and diamond. Research in this area has made great progress.
    Preview · Article · Sep 2001 · Nuclear Instruments and Methods in Physics Research Section B Beam Interactions with Materials and Atoms
  • [Show abstract] [Hide abstract]
    ABSTRACT: The BNM-LNHB (formerly BNM-LPRI, the French national standard laboratory for ionizing radiation) is equipped with a SATURNE 43 linear accelerator (GE Medical Systems) dedicated to establishing national references of absorbed dose to water for high-energy photon and electron beams. These standards are derived from a dose measurement with a graphite calorimeter and a transfer procedure to water using Fricke dosimeters. This method has already been used to obtain the reference of absorbed dose to water for cobalt-60 beams. The correction factors rising from the perturbations generated by the dosimeters were determined by Monte Carlo calculations. To meet these applications, the Monte Carlo code PENELOPE was used and user codes were specially developed. The first step consisted of simulating the electron and photon showers produced by primary electrons within the accelerator head to determine the characteristics of the resulting photon beams and absorbed dose distributions in a water phantom. These preliminary computations were described in a previous paper. The second step, described in this paper, deals with the calculation of the perturbation correction factors of the graphite calorimeter and of Fricke dosimeters. To point out possible systematic biases, these correction factors were calculated with another Monte Carlo code, EGS4, widely used for years in the field of dose metrology applications. Comparison of the results showed no significant bias. When they were possible, experimental verifications confirmed the calculated values.
    No preview · Article · Jul 2001 · Physics in Medicine and Biology
  • J. Mazurier · F. Salvat · B. Chauvenet · J. Barthe
    [Show abstract] [Hide abstract]
    ABSTRACT: The Monte Carlo code system PENELOPE was used to simulate photon beams from the Saturne 43 accelerator at the BNM-LPRI and the corresponding three- dimensional dose distributions in water. The characteristics of the simulated beams at the output of the accelerator head were recorded in a phase space file, which contained a complete description of the simulated particle fluence. Special care was taken to estimate statistical uncertainties and to identify those that are latent in the phase space file. Different variance reduction techniques were applied at various stages of the simulation. The dependence of the dose distributions on the energy of primary electrons was analyzed. Close agreement between simulated and measured doses was obtained by assuming a monoenergetic primary electron beam and determining its initial energy from the value of the electric current in the deflecting coils. Simulation results are presented for 10x10 cm2 photon beams with nominal energies of 6, 12 and 25 MV.
    No preview · Article · Jul 1999 · Physica Medica
  • J.M. Bordy · T Lahaye · F. Landre · C. Hoflack · S. Lequin · J. Barthe
    [Show abstract] [Hide abstract]
    ABSTRACT: A new method using one PN junction covered with a hydrogenous converter (10B-loaded) is proposed for individual neutron dosimetry. This method is based on a pulse shape analysis to discriminate the photon signal from the neutron signal. This method allows drastic reduction of the photon sensitivity (by a factor of 1000). Additionally, when using photon correction factor, the photon response becomes negligible. By applying a neutron correction factor to the low energy events, the gap in neutron sensitivity for intermediate energy can be partly filled. Lead shields used to surround the detector allow the remaining photon sensitivity to be decreased by a factor of two. An especially designed hydrogenous moderator placed at the top of the detector allows the neutron sensitivity to be increased by a factor of two for 250 keV neutron energy.
    No preview · Article · Apr 1997 · Radiation Protection Dosimetry
  • [Show abstract] [Hide abstract]
    ABSTRACT: Different options were investigated in the development of active neutron dosemeters for personnel and area monitoring. In particular, two different classes of detectors, superheated emulsions and silicon diodes, were studied as radiation sensors for such devices. The detectors were analysed with respect to their neutron sensitivity and their overall suitability for practical dosimetry. Superheated emulsions proved adequate in terms of their dose equivalent response and their photon discrimination: future work should now focus on the development of a rugged device. Significant improvements were also achieved with the diode sensors, although more research will be necessary for the design of a simple, single structure readily usable as a neutron dosemeter.
    No preview · Article · Apr 1997 · Radiation Protection Dosimetry
  • J. Barthe · J M Bordy · T Lahaye
    [Show abstract] [Hide abstract]
    ABSTRACT: A review of the development of electronic neutron dosemeters is given, with an assessment of their characteristics. Comment is made on necessary lines for future development.
    No preview · Article · Apr 1997 · Radiation Protection Dosimetry
  • J. M. BORDY · J. BARTHE · B. BOUTRUCHE · P. SEGUR

    No preview · Article · Jan 1994 · Radioprotection
  • [Show abstract] [Hide abstract]
    ABSTRACT: In order to understand better the origin of the TL UV emission in CaSO4:Dy, several factors have been studied such as the influence of the pre-annealing temperature, the Dy concentration and the effect of the dose, on two compounds, one commercially available and the other synthesised in the laboratory. A UV induced TL phototransfer is observed between 20 and 400°C for the former. Application to high temperature dosimetry of CaSO4:Dy is discussed.
    No preview · Article · Jan 1993 · Radiation Protection Dosimetry
  • J. Barthe · C. Hickman · R. Heindl · G. Portal
    [Show abstract] [Hide abstract]
    ABSTRACT: The increasingly wide spread use of electronuclear energy has led to the need for an improved knowledge of the radiation doses received by various structural materials. Dose rates are particularly high in regions in the vicinity of the core of a reactor, steam generators and the pool in which spent fuel elements are stored; high dose rates will also be encountered at high-level waste disposal sites. In most, involving gamma radiations resulting from the de-activation of fission products, thermal conditions can be problematic: temperatures as high as 300°C can be reached inside the core or steam generators. Preliminary tests performed in high-level waste disposal environments suggest that similar temperatures are likely to be reached. Thermoluminescence (TL) dosimetry can be employed if certain conditions are satisfied: the TL products must possess at least one deep trap and must also be sensitive over a sufficiently wide dynamic range. The following materials have been investigated for this purpose: dysprosium doped calcium sulphate powder, alumina and cerium doped ceramic glasses. The maximum dose measurable depends on the material employed and ranges from a fraction of a kilogray for alumina, to a few kilograys for calcium sulphate and cerium doped glasses. A comparative study of the various available products has been performed in order to define the limits and to optimise their use.
    No preview · Article · Jan 1993 · Radiation Protection Dosimetry
  • G Marinello · J Barthe · J Pollack · G Portal
    [Show abstract] [Hide abstract]
    ABSTRACT: The authors present a new automatic TLD reader specially designed for medical dosimetric applications, which allow considerable time-saving. The "PCL" reader is based on an isothermal heating kinetics and can be used with TL material of any nature and any shape (powder, microrods, pellets). Doses from 1 microGy to 10 Gy can be measured, or higher doses by interposing an optical absorber in front of the PM. The readout system is controlled by an IBM compatible personal computer. Results can be printed under the form defined by the users and then can be straightly stored in a patient sheet or an experience book. Tests performed with LiF chips TLD 100 and 700 (HARSHAW), Li2B4O7:Mn discs LiB (ALNOR), LiF powder PTL 717 (DESMARQUET) and Li2B4O7:Cu powder (CEN-FAR) are presented. They show a good reproducibility and interesting dosimetric properties.
    No preview · Article · Oct 1992 · Radiotherapy and Oncology
  • J. Barthe · G. Marinello · J. Pollack · G. Portal
    [Show abstract] [Hide abstract]
    ABSTRACT: A new fast automatic and computerised reader of TL powder and sintered pellets for medical dosimetric applications is described. Some results obtained are presented.
    No preview · Article · Jan 1990 · Radiation Protection Dosimetry
  • G. MARINELLO · J. POLLACK · P. BLANCHARD · J. BARTHE

    No preview · Article · Jan 1990 · Radioprotection

Publication Stats

205 Citations
29.87 Total Impact Points

Institutions

  • 2001-2009
    • Cea Leti
      Grenoble, Rhône-Alpes, France
  • 1983-2008
    • Atomic Energy and Alternative Energies Commission
      Fontenay, Île-de-France, France
  • 1999
    • University of Barcelona
      Barcino, Catalonia, Spain
  • 1989
    • Institut de France
      Lutetia Parisorum, Île-de-France, France
  • 1971-1979
    • Paul Sabatier University - Toulouse III
      Tolosa de Llenguadoc, Midi-Pyrénées, France