J. Barthe

Cea Leti, Grenoble, Rhône-Alpes, France

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Publications (38)26.55 Total impact

  • B Habib · B Poumarede · F Tola · J Barthe ·
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    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.
    Physica Medica 04/2009; 26(1):17-25. DOI:10.1016/j.ejmp.2009.03.002 · 2.40 Impact Factor
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    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 Al(2)O(3):C fibre crystals (TLD(500)) have been tested with an X-ray generator. A reproducible readout procedure should reduce the fading-induced uncertainty ( approximately - 1% per decade). OSL readouts are temperature-dependent [ approximately 0.3% K(-1) when OSL stimulation is performed at the same temperature as irradiation; approximately 0.16% K(-1) after thermalisation (20 degrees 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.
    Radiation Protection Dosimetry 09/2008; 131(1):93-9. DOI:10.1093/rpd/ncn226 · 0.91 Impact Factor
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    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.
  • Jean Barthe · Régis Hugon · Jean Philippe Nicolai ·
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    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.
    Nuclear Instruments and Methods in Physics Research Section A Accelerators Spectrometers Detectors and Associated Equipment 12/2007; DOI:10.1016/j.nima.2007.08.183 · 1.22 Impact Factor
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    Baptiste Blanpain · David Mercier · Jean Barthe ·
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    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.
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    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.
    Proceedings of SPIE - The International Society for Optical Engineering 01/2007; 6619. DOI:10.1117/12.738604 · 0.20 Impact Factor
  • J. Barthe · B. Chauvenet · J.-M. Bordy ·

    Radioprotection 01/2006; 41. DOI:10.1051/radiopro:2007012 · 0.54 Impact Factor
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    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.).
    2ièmes Journées scientifiques francophones, Codes de calcul en radioprotection, radiophysique et dosimétrie (SFPM, SFRP, LARD); 10/2003
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    Jean Barthe ·
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    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.
    Nuclear Instruments and Methods in Physics Research Section B Beam Interactions with Materials and Atoms 09/2001; 184(1):158-189. DOI:10.1016/S0168-583X(01)00711-X · 1.12 Impact Factor
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    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.
    Physics in Medicine and Biology 07/2001; 46(6):1707-17. DOI:10.1088/0031-9155/46/6/309 · 2.76 Impact Factor
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    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.
    Radiation Protection Dosimetry 04/1997; 70(1). DOI:10.1093/oxfordjournals.rpd.a032023 · 0.91 Impact Factor
  • J. Barthe · J M Bordy · T Lahaye ·
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    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.
    Radiation Protection Dosimetry 04/1997; 70(1). DOI:10.1093/oxfordjournals.rpd.a032020 · 0.91 Impact Factor
  • J M Bordy · T Lahaye · F. Landre · C. Hoflack · S. Lequin · J. Barthe ·
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    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.
    Radiation Protection Dosimetry 04/1997; 70(1). DOI:10.1093/oxfordjournals.rpd.a032022 · 0.91 Impact Factor

    Radioprotection 01/1994; 29(1):11-28. DOI:10.1051/radiopro/1994019 · 0.54 Impact Factor
  • D. Goyet · D. Lapraz · P. Iacconi · G. Portal · J. Barthe · H. Prevost · J. Gasiot ·
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    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.
    Radiation Protection Dosimetry 01/1993; 47(1):147-150. · 0.91 Impact Factor
  • G Marinello · J Barthe · J Pollack · G Portal ·
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    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.
    Radiotherapy and Oncology 10/1992; 25(1):63-6. DOI:10.1016/0167-8140(92)90197-3 · 4.36 Impact Factor
  • J. Barthe · G. Marinello · J. Pollack · G. Portal ·
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    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.
    Radiation Protection Dosimetry 01/1990; 34(1):261-263. · 0.91 Impact Factor

    Radioprotection 01/1990; 25(2):157-167. DOI:10.1051/radiopro/1990022 · 0.54 Impact Factor
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    ABSTRACT: Measurements of free-radical densities in clothing fabric constitutes a useful method for determining doses received in the case of accidental irradiation. Measurements are made by electron spin resonance. Most fabrics exhibit poor radiation sensitivities; however cotton and polypropylene can be used for this purpose. It is necessary to determine the intrinsic signal from the non-irradiated fabrics in order to lower the detection threshold as much as possible (1 Gy for cotton and 0.5 Gy for polypropylene). A study of the thermal kinetics of free radicals in fabrics has enabled a procedure to be developed for the accurate determination of the background noise signal from polypropylene. The relatively high threshold values (≈ 1 Gy) encountered with this method prevent it from being used for personal dosimetry. However in the case of accidental irradiation, very useful information can be obtained on dose distributions. Medical treatment can then be based on this information.
    International Journal of Radiation Applications and Instrumentation Part A Applied Radiation and Isotopes 01/1989; 40(10-12):1029-1033. DOI:10.1016/0883-2889(89)90036-1
  • D. Lapraz · P. Iacconi · Y. Sayadi · P. Keller · J. Barthe · G. Portal ·
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    ABSTRACT: The thermoluminescence (TL) properties of an α-Al2O3 sample are studied from 77 to 1000 K after X-irradiation and UV-excitation. Nine trapping centres and three emission centres, namely F, F+, and Cr3+, are detected. The UV-253.7 nm TL response is sensitized by previous X-irradiations followed by various thermal annealings. All TL properties of the virgin crystal are found again by heating up to 910 K, i.e. after the annealing of the TL peak at 910 K. Charge transfers, by UV-excitation (PITL) or in darkness (“dark transfer”), are involved in α-Al2O3.Les propriétés de thermoluminescence (TL) d'une alumine α sont étudiées de 77 à 1000 K après irradiation X et excitation UV. Neuf centres de piégeage sont mis en évidence ainsi que trois centres d'émission: F, F+ et Cr3+. La réponse aux UV-253,7 nm est sensibilisée par des irradiations préalables suivies par divers recuits thermiques. Toutes les propriétes du cristal vierge sont retrouvées après recuit de l'échantillon au delà de 910 K, c'est-à-dire après vidage du pic de TL à 910 K. Des processus de transfert de charges, soit par excitation UV (PITL), soit à l'obscurité (“dark transfer”) sont impliqués.
    physica status solidi (a) 08/1988; 108(2):783-794. DOI:10.1002/pssa.2211080237 · 1.21 Impact Factor

Publication Stats

186 Citations
26.55 Total Impact Points


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