40 results on '"Boudou C"'
Search Results
2. Dosimetry for synchrotron stereotactic radiotherapy: Fricke gel and Monte Carlo calculations
- Author
-
Boudou, C., Biston, M.-C., Corde, S., Adam, J.-F., Joubert, A., Charvet, A.-M., Nemoz, C., Ferrero, C., Estève, F., and Elleaume, H.
- Published
- 2005
- Full Text
- View/download PDF
3. Fast Dose Calculation for Stereotactic Synchrotron Radiotherapy
- Author
-
Freud, N, Letang, J, Mary, C, Boudou, C, Ferrero, C, Elleaume, H, Bravin, A, Esteve, F, Babot, D, Freud N, Letang JM, Mary C, Boudou C, Ferrero C, Elleaume H, Bravin A, Esteve F, Babot D, Freud, N, Letang, J, Mary, C, Boudou, C, Ferrero, C, Elleaume, H, Bravin, A, Esteve, F, Babot, D, Freud N, Letang JM, Mary C, Boudou C, Ferrero C, Elleaume H, Bravin A, Esteve F, and Babot D
- Abstract
A hybrid approach is proposed to compute the dose deposited in cancerous and healthy tissues during stereotactic synchrotron radiotherapy treatment. In this approach the computation is divided into two parts: (1) the primary dose is calculated using a deterministic algorithm based on ray casting; (2) the secondary dose (due to scattering and fluorescence) is computed using a hybrid algorithm combining Monte Carlo and a deterministic method. The results obtained for test cases are compared to those obtained with the Monte Carlo method alone (Geant4 code) and found to be in excellent agreement. The proposed simulation scheme makes it possible to simulate dose maps with a single personal computer, with computation time and statistical fluctuations substantially reduced in comparison with conventional Monte Carlo simulations. © 2007 IEEE.
- Published
- 2007
4. Synchrotron radiation computed tomography station at the ESRF biomedical beamline
- Author
-
Choi, JY, Rah, S, Nemoz, C, Bayat, S, Berruyer, G, Brochard, T, Coan, P, Le Duc, G, Keyrilainen, J, Monfraix, S, Renier, M, Requardt, H, Bravin, A, Tafforeau, P, Adam, J, Biston, M, Boudou, C, Charvet, A, Corde, S, Elleaume, H, Esteve, F, Joubert, A, Rousseau, J, Tropres, I, Fernandez, M, Porra, L, Suortti, P, Fiedler, S, Thomlinson, W, Nemoz C., Bayat S., Berruyer G., Brochard T., Coan P., Le Duc G., Keyrilainen J., Monfraix S., Renier M., Requardt H., Bravin A, Tafforeau P., Adam J. F., Biston M. C., Boudou C., Charvet A. M., Corde S., Elleaume H., Esteve F., Joubert A., Rousseau J., Tropres I., Fernandez M., Porra L., Suortti P., Fiedler S., Thomlinson W, Choi, JY, Rah, S, Nemoz, C, Bayat, S, Berruyer, G, Brochard, T, Coan, P, Le Duc, G, Keyrilainen, J, Monfraix, S, Renier, M, Requardt, H, Bravin, A, Tafforeau, P, Adam, J, Biston, M, Boudou, C, Charvet, A, Corde, S, Elleaume, H, Esteve, F, Joubert, A, Rousseau, J, Tropres, I, Fernandez, M, Porra, L, Suortti, P, Fiedler, S, Thomlinson, W, Nemoz C., Bayat S., Berruyer G., Brochard T., Coan P., Le Duc G., Keyrilainen J., Monfraix S., Renier M., Requardt H., Bravin A, Tafforeau P., Adam J. F., Biston M. C., Boudou C., Charvet A. M., Corde S., Elleaume H., Esteve F., Joubert A., Rousseau J., Tropres I., Fernandez M., Porra L., Suortti P., Fiedler S., and Thomlinson W
- Abstract
The different tomography imaging modalities of the ESRF Medical Beamline are described and research applications are presented.
- Published
- 2007
5. Fast simulation of dose deposition in Stereotactic Synchrotron RadioTherapy (SSRT)
- Author
-
Létang, J M, Freud, N., Smekens, F., Boudou, C., Ferrero, C., Elleaume, H., Bravin, A., Estève, F., Babot, D., Imagerie Tomographique et Radiothérapie, Centre de Recherche en Acquisition et Traitement de l'Image pour la Santé (CREATIS), Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut National des Sciences Appliquées de Lyon (INSA Lyon), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Université Jean Monnet - Saint-Étienne (UJM)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Université Jean Monnet - Saint-Étienne (UJM)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS), Centre Léon Bérard [Lyon], Controle Non Destructif par Rayonnements Ionisants (CNDRI), Institut National des Sciences Appliquées de Lyon (INSA Lyon), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Université de Lyon-Institut National des Sciences Appliquées (INSA), Commissariat à l'énergie atomique et aux énergies alternatives - Laboratoire d'Electronique et de Technologie de l'Information (CEA-LETI), Direction de Recherche Technologique (CEA) (DRT (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), European Synchrotron Radiation Facility (ESRF), Grenoble Institut des Neurosciences (GIN), Université Joseph Fourier - Grenoble 1 (UJF)-Institut National de la Santé et de la Recherche Médicale (INSERM), Centre de Recherche et d'Application en Traitement de l'Image et du Signal (CREATIS), Université de Lyon-Université de Lyon-École Supérieure de Chimie Physique Électronique de Lyon (CPE)-Institut National des Sciences Appliquées de Lyon (INSA Lyon), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS), Institut National des Sciences Appliquées (INSA)-Université de Lyon-Institut National des Sciences Appliquées (INSA)-Hospices Civils de Lyon (HCL)-Université Jean Monnet [Saint-Étienne] (UJM)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Université Claude Bernard Lyon 1 (UCBL), Institut National des Sciences Appliquées (INSA)-Université de Lyon-Institut National des Sciences Appliquées (INSA)-Hospices Civils de Lyon (HCL)-Université Jean Monnet [Saint-Étienne] (UJM)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS), Institut National des Sciences Appliquées (INSA)-Université de Lyon-Institut National des Sciences Appliquées (INSA)-Université de Lyon, and Institut National des Sciences Appliquées (INSA)-Université de Lyon-Institut National des Sciences Appliquées (INSA)-École Supérieure Chimie Physique Électronique de Lyon-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)
- Subjects
[INFO.INFO-IM]Computer Science [cs]/Medical Imaging ,ComputingMilieux_MISCELLANEOUS - Abstract
International audience
- Published
- 2008
6. A hybrid approach for fast simulation of dose deposition in stereotactic synchrotron radiotherapy
- Author
-
Freud, N, Letang Jean, M, Mary, C, Boudou, C, Ferrero, C, Elleaume, H, Bravin, A, Esteve, F, Babot, D, Freud Nicolas, Letang Jean Michel, Mary Corentin, Boudou Caroline, Ferrero Claudio, Elleaume Helene, Bravin A, Esteve Francois, Babot Daniel, Freud, N, Letang Jean, M, Mary, C, Boudou, C, Ferrero, C, Elleaume, H, Bravin, A, Esteve, F, Babot, D, Freud Nicolas, Letang Jean Michel, Mary Corentin, Boudou Caroline, Ferrero Claudio, Elleaume Helene, Bravin A, Esteve Francois, and Babot Daniel
- Abstract
A hybrid approach was developed to compute the dose deposited in cancerous and healthy tissues during stereotactic synchrotron radiation therapy treatment. The proposed approach divides the computation into two parts: (1) the dose deposited by primary radiation (coming directly from the incident X-ray beam) is calculated using a deterministic algorithm based on ray casting, optimized for transport in voxelized geometries; (2) the dose deposited by secondary radiation (Rayleigh and Compton scattering, fluorescence) is computed using a hybrid algorithm combining Monte Carlo and deterministic calculations. In the Monte Carlo part, a set of scattering and fluorescence events occurring in the patient is determined. These events are further processed in a deterministic way, which considerably improves the statistics of the final dose map. The results obtained in test cases are compared to those obtained with the Monte Carlo method alone (Geant4 and MCNPX codes) and found to be in excellent agreement. The proposed simulation scheme makes it possible to simulate dose maps with a single PC, featuring computation time and statistical fluctuations substantially reduced in comparison with full Monte Carlo simulations.
- Published
- 2008
7. Fast CdTe and CdZnTe Semiconductor Detector Arrays for Spectroscopic X-Ray Imaging
- Author
-
Brambilla, Andrea, primary, Ouvrier-Buffet, P., additional, Gonon, G., additional, Rinkel, J., additional, Moulin, V., additional, Boudou, C., additional, and Verger, L., additional
- Published
- 2013
- Full Text
- View/download PDF
8. Synchrotron radiation computed tomography station at the ESRF biomedical beamline
- Author
-
Nemoz, C, Bayat, S, Berruyer, G, Brochard, T, Coan, P, Le Duc, G, Keyrilainen, J, Monfraix, S, Renier, M, Requardt, H, Bravin, A, Tafforeau, P, Adam, J F, Biston, M C, Boudou, C, Charvet, A M, corde, s, Elleaume, H, Esteve, F, Joubert, A, Rousseau, J, Tropres, I, Fernandez, M, Porra, L, Suortti, P, Fiedler, S, Thomlinson, W, Nemoz, C, Bayat, S, Berruyer, G, Brochard, T, Coan, P, Le Duc, G, Keyrilainen, J, Monfraix, S, Renier, M, Requardt, H, Bravin, A, Tafforeau, P, Adam, J F, Biston, M C, Boudou, C, Charvet, A M, corde, s, Elleaume, H, Esteve, F, Joubert, A, Rousseau, J, Tropres, I, Fernandez, M, Porra, L, Suortti, P, Fiedler, S, and Thomlinson, W
- Abstract
The different tomography imaging modalities of the ESRF Medical Beamline are described and research applications are presented
- Published
- 2007
9. Dosimetry for synchrotron stereotactic radiotherapy: fricke gel and Monte Carlo calculations
- Author
-
Boudou, C, Biston, M-C, corde, s, Adam, J-F, Joubert, A, Charvet, A-M, Nemoz, C, Ferrero, C, Esteve, F, Elleaume, H, Boudou, C, Biston, M-C, corde, s, Adam, J-F, Joubert, A, Charvet, A-M, Nemoz, C, Ferrero, C, Esteve, F, and Elleaume, H
- Abstract
In Synchrotron stereotactic radiotherapy (SSR) the tumor is loaded with atoms ofhigh atomic number (Z) element, and exposed to monochromatic X-rays from a synchrotron source (50-100 keV), in stereotactic conditions. This method is under investigation at the European Synchrotron Radiation Facility (ESRF) for the treatment of brain tumors. Conventional treatment planning systems are not suitable for SSR since the beam energy, the irradiation geometry and the presence ofhigh Z elements differ from commercial systems. Therefore, SSR requires the development of new procedures for the evaluation of dose maps. Monte Carlo (MC) method offers the potential of calculating the dose in complicated geometries, made ofheterogeneous materials. MC calculations were performed using the MCNP4C general purpose code. Gel dosimetry allows accurate experimental verification ofthree-dimensional absorbed dose distributions from any irradiation geometries. In this study, the Fricke chemical dosimeter was employed for it is easy to prepare without special facilities. Various phantoms filled with Fricke gel were irradiated in SSR configuration. The dose profiles obtained were compared with MC simulations.
- Published
- 2005
10. CdTe Linear Pixel X-Ray Detector With Enhanced Spectrometric Performance for High Flux X-Ray Imaging
- Author
-
Brambilla, A., primary, Ouvrier-Buffet, P., additional, Rinkel, J., additional, Gonon, G., additional, Boudou, C., additional, and Verger, L., additional
- Published
- 2012
- Full Text
- View/download PDF
11. Fricke dosimetry for synchrotron stereotactic radiotherapy
- Author
-
Boudou, C, Biston, M C, Adam, J F, Joubert, A, corde, s, Charvet, A M, Esteve, F, Elleaume, H, Boudou, C, Biston, M C, Adam, J F, Joubert, A, corde, s, Charvet, A M, Esteve, F, and Elleaume, H
- Abstract
In synchrotron stereotactic radiotherapy (SSR) the tumor is loaded with a high Z element, and exposed to monochromatic x-rays from a synchrotron source, in stereotactic conditions. The SSR treatment efficiency is related to the heavy element concentration achievable in the tumor, to the radiation energy, and the irradiation geometry [1,2]. The experimental dose verification of SSR in three dimensions with a good spatial resolution is highly desirable for radiotherapy [3]. In this study, Fricke dosimeter and Monte Carlo calculations were employed for assessing 2D dose distribution.
- Published
- 2004
12. CdTe linear pixel X-ray detector with enhanced spectrometric performance for high flux X-ray imaging
- Author
-
Brambilla, A., primary, Ouvrier-Buffer, P., additional, Rinkel, J., additional, Gonon, G., additional, Boudou, C., additional, and Verger, L., additional
- Published
- 2011
- Full Text
- View/download PDF
13. Experimental evaluation of material identification methods with CdTe X-rays spectrometric detector
- Author
-
Rinkel, J, primary, Beldjoudi, G, additional, Gonon, G, additional, Brambilla, A, additional, Rebuffel, V, additional, Boudou, C, additional, Ouvrier-Buffet, P, additional, and Verger, L, additional
- Published
- 2010
- Full Text
- View/download PDF
14. Spectrometric performances of CdTe and CdZnTe semiconductor detector arrays at high X-ray flux
- Author
-
Brambilla, A., primary, Boudou, C., additional, Ouvrier-Buffet, P., additional, Mougel, F., additional, Gonon, G., additional, Rinkel, J., additional, and Verger, L., additional
- Published
- 2009
- Full Text
- View/download PDF
15. CdTe and CdZnTe semiconductor detector arrays for fast spectroscopic x-ray imaging
- Author
-
Brambilla, A., primary, Ouvrier-Buffet, P., additional, Gonon, G., additional, Rinkel, J., additional, Verger, L., additional, and Boudou, C., additional
- Published
- 2009
- Full Text
- View/download PDF
16. Polymer gel dosimetry for synchrotron stereotactic radiotherapy and iodine dose-enhancement measurements
- Author
-
Boudou, C, primary, Troprès, I, additional, Rousseau, J, additional, Lamalle, L, additional, Adam, J F, additional, Estève, F, additional, and Elleaume, H, additional
- Published
- 2007
- Full Text
- View/download PDF
17. Ionic Liquids: Valuable Solvents for Palladium Catalyzed C—P Cross‐Coupling Reactions.
- Author
-
Vallette, H., primary, Pican, S., additional, Boudou, C., additional, Levillain, J., additional, Plaquevent, J. C., additional, and Gaumont, A. C., additional
- Published
- 2007
- Full Text
- View/download PDF
18. Synchrotron Radiation Computed Tomography Station at the ESRF Biomedical Beamline
- Author
-
Nemoz, C., primary, Bayat, S., additional, Berruyer, G., additional, Brochard, T., additional, Coan, P., additional, Le Duc, G., additional, Keyrilainen, J., additional, Monfraix, S., additional, Renier, M., additional, Requardt, H., additional, Bravin, A., additional, Tafforeau, P., additional, Adam, J. F., additional, Biston, M. C., additional, Boudou, C., additional, Charvet, A. M., additional, Corde, S., additional, Elleaume, H., additional, Estève, F., additional, Joubert, A., additional, Rousseau, J., additional, Tropres, I., additional, Fernandez, M., additional, Porra, L., additional, Suortti, P., additional, Fiedler, S., additional, and Thomlinson, W., additional
- Published
- 2007
- Full Text
- View/download PDF
19. CMR 2005: 3.07: High‐Z compounds for synchrotron stereotactic radiotherapy: developments and perspectives
- Author
-
Estève, F., primary, Adam, J.F., additional, Biston, M.C., additional, Joubert, A., additional, Corde, S., additional, Boudou, C., additional, Rousseau, J., additional, Gastaldo, J., additional, Bencokova, Z., additional, Charvet, A.M., additional, Foray, N., additional, Le Bas, J.F., additional, Balosso, J., additional, and Elleaume, H., additional
- Published
- 2006
- Full Text
- View/download PDF
20. Aminopropargyl derivative of terpyridine-bis(methyl-enamine) tetraacetic acid chelate of europium (Eu (TMT)-AP3): a new reagent for fluorescent labelling of proteins and peptides
- Author
-
Poupart, S?verine, primary, Boudou, C?dric, additional, Peixoto, Philippe, additional, Massonneau, Marc, additional, Renard, Pierre-Yves, additional, and Romieu, Anthony, additional
- Published
- 2006
- Full Text
- View/download PDF
21. Experimental evaluation of material identification methods with CdTe X-rays spectrometric detector.
- Author
-
Rinkel, J., Beldjoudi, G., Gonon, G., Brambilla, A., Rebuffel, V., Boudou, C., Ouvrier-Buffet, P., and Verger, L.
- Published
- 2010
- Full Text
- View/download PDF
22. Fast Dose Calculation for Stereotactic Synchrotron Radiotherapy.
- Author
-
Freud, N., Letang, J.M., Mary, C., Babot, D., Bravin, A., Ferrero, C., Esteve, F., Boudou, C., and Elleaume, H.
- Published
- 2007
- Full Text
- View/download PDF
23. Synthesis of Lithium 1-Alkynesulfenates by the Mild Oxidation of Thiolates with a Pinacolone-Derived N-Sulfonyloxaziridine.
- Author
-
Sandrinelli, Franck, Boudou, C�dric, Caup�ne, Caroline, Averbuch-Pouchot, Marie-Th�r�se, Perrio, St�phane, and Metzner, Patrick
- Published
- 2006
- Full Text
- View/download PDF
24. Fricke dosimetry for synchrotron stereotactic radiotherapy.
- Author
-
Boudou, C., Biston, M. C., Adam, J. F., Joubert, A., Corde, S., Charvet, A. M., Estève, F., and Elleaume, H.
- Published
- 2004
- Full Text
- View/download PDF
25. Horizonte Humanista e Fenomenologia na Geografia: o problema da assimilação humanista do pensamento de Martin Heidegger
- Author
-
SANTOS, J. M., BOUDOU, C. J., FREIRE, A. L. O., and REIS, L. C. T. D.
- Abstract
Made available in DSpace on 2018-08-01T23:45:51Z (GMT). No. of bitstreams: 1 tese_11510_Dissertação Josimar Monteiro20180406-93909.pdf: 1243835 bytes, checksum: 98e14ea445aaf4bc3436ebbd800c8f50 (MD5) Previous issue date: 2017-12-08 Resumo da dissertação: A pesquisa proposta se estabelece pela relação entre dois elementos básicos, por um lado o horizonte humanista na Geografia e, por outro lado, a fenomenologia. A articulação desses elementos na pesquisa proposta se dá através da problematização da leitura humanista dispensada ao pensamento de Heidegger no horizonte humanista da ciência geográfica. O objetivo geral da pesquisa consiste em ratificar que o pensamento de Heidegger é frontalmente incompatível com qualquer modalidade de Humanismo - a despeito do fato da própria constituição da Geografia humanista, na década de 1970, tenha se desenvolvido através da filiação à fenomenologia, destacando-se, nesse contexto, a referência expressa à obra de Heidegger. Esse objetivo se justifica quando se observa o estado da arte atual sobre o assunto na disciplina, na medida em que, não obstante a referida incompatibilidade já tenha sido trazida à tona no debate interno da ciência geográfica, de modo patente, desde meados da década de 1980, a requisição ao pensamento de Heidegger como matriz fenomenológica para a perspectiva humanista permaneceu se reproduzindo nas décadas subsequentes, como atestam publicações recentes que incidem na filiação ao filósofo para fomentar a perspectiva humanista na geografia. Trata-se de uma leitura particularmente recorrente nos rumos que, sobretudo a partir da década de 1990, se desenvolveu na pesquisa brasileira vinculada à Geografia humanista. Pretende-se, desse modo, contribuir à pesquisa geográfica sobre o assunto, evidenciando que a leitura humanista do filósofo tende a obstruir o propósito primordial que deveria conduzir a relação entre uma ciência particular, no caso a Geografia, e o pensamento de Heidegger, a saber: reabilitar a investigação sobre a fundamentação ontológica da respectiva ciência. Isso implicaria a necessidade do geógrafo assumir, antes de tudo, a analítica do ser-aí (exposta de modo paradigmático em Ser e Tempo) como fio condutor à investigação ontológica através da fenomenologia-hermenêutica de Heidegger, na medida em a referida analítica constitui, para o filósofo, a fonte da ontologia fundamental de onde todas as ontologias derivariam.
- Published
- 2017
26. A hybrid approach for fast simulation of dose deposition in stereotactic synchrotron radiotherapy
- Author
-
Claudio Ferrero, Alberto Bravin, Daniel Babot, H. Elleaume, Nicolas Freud, Jean Michel Létang, C. Boudou, C. Mary, François Estève, Freud, N, Letang Jean, M, Mary, C, Boudou, C, Ferrero, C, Elleaume, H, Bravin, A, Esteve, F, Babot, D, Controle Non Destructif par Rayonnements Ionisants (CNDRI), Institut National des Sciences Appliquées de Lyon (INSA Lyon), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Université de Lyon-Institut National des Sciences Appliquées (INSA), CCIN2P3, and Institut National des Sciences Appliquées (INSA)-Université de Lyon-Institut National des Sciences Appliquées (INSA)-Université de Lyon
- Subjects
Nuclear and High Energy Physics ,Hybrid simulation ,Deterministic algorithm ,Quantitative Biology::Tissues and Organs ,Physics::Medical Physics ,Monte Carlo method ,Synchrotron radiation ,FIS/07 - FISICA APPLICATA (A BENI CULTURALI, AMBIENTALI, BIOLOGIA E MEDICINA) ,Statistical fluctuations ,Fluorescence ,030218 nuclear medicine & medical imaging ,03 medical and health sciences ,symbols.namesake ,0302 clinical medicine ,Optics ,Deterministic simulation ,Dosimetry ,Electrical and Electronic Engineering ,Rayleigh scattering ,Physics ,business.industry ,Dose calculation ,Compton scattering ,Ray casting ,3. Good health ,Nuclear Energy and Engineering ,030220 oncology & carcinogenesis ,symbols ,[SDV.IB]Life Sciences [q-bio]/Bioengineering ,business ,Stereotactic synchrotron radiation therapy ,Treatment planning ,Rayleigh and Compton scattering - Abstract
International audience; A hybrid approach was developed to compute the dose deposited in cancerous and healthy tissues during stereotactic synchrotron radiation therapy treatment. The proposed approach divides the computation into two parts: (1) the dose deposited by primary radiation (coming directly from the incident X-ray beam) is calculated using a deterministic algorithm based on ray casting, optimized for transport in voxelized geometries; (2) the dose deposited by secondary radiation (Rayleigh and Compton scattering, fluorescence) is computed using a hybrid algorithm combining Monte Carlo and deterministic calculations. In the Monte Carlo part, a set of scattering and fluorescence events occurring in the patient is determined. These events are further processed in a deterministic way, which considerably improves the statistics of the final dose map. The results obtained in test cases are compared to those obtained with the Monte Carlo method alone (Geant4 and MCNPX codes) and found to be in excellent agreement. The proposed simulation scheme makes it possible to simulate dose maps with a single PC, featuring computation time and statistical fluctuations substantially reduced in comparison with full Monte Carlo simulations.
- Published
- 2008
27. Fast Dose Calculation for Stereotactic Synchrotron Radiotherapy
- Author
-
Daniel Babot, Claudio Ferrero, Jean Michel Létang, Caroline Boudou, Nicolas Freud, C. Mary, Hélène Elleaume, François Estève, Alberto Bravin, Controle Non Destructif par Rayonnements Ionisants (CNDRI), Institut National des Sciences Appliquées de Lyon (INSA Lyon), Institut National des Sciences Appliquées (INSA)-Université de Lyon-Institut National des Sciences Appliquées (INSA)-Université de Lyon, Imagerie Tomographique et Radiothérapie, Centre de Recherche en Acquisition et Traitement de l'Image pour la Santé (CREATIS), Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut National des Sciences Appliquées de Lyon (INSA Lyon), Institut National des Sciences Appliquées (INSA)-Université de Lyon-Institut National des Sciences Appliquées (INSA)-Hospices Civils de Lyon (HCL)-Université Jean Monnet [Saint-Étienne] (UJM)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Université Claude Bernard Lyon 1 (UCBL), Institut National des Sciences Appliquées (INSA)-Université de Lyon-Institut National des Sciences Appliquées (INSA)-Hospices Civils de Lyon (HCL)-Université Jean Monnet [Saint-Étienne] (UJM)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS), Centre Léon Bérard [Lyon], INSERM U836, équipe 6, Rayonnement synchrotron et recherche médicale, Grenoble Institut des Neurosciences (GIN), Université Joseph Fourier - Grenoble 1 (UJF)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut National de la Santé et de la Recherche Médicale (INSERM), European Synchrotron Radiation Facility (ESRF), Université Joseph Fourier - Grenoble 1 (UJF)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut National de la Santé et de la Recherche Médicale (INSERM)-CHU Grenoble, Université Joseph Fourier - Grenoble 1 (UJF)-CHU Grenoble-CHU Grenoble-Biomedical Beamline (ID17), European Synchrotron Radiation Facility (ESRF)-European Synchrotron Radiation Facility (ESRF), Freud, N, Letang, J, Mary, C, Boudou, C, Ferrero, C, Elleaume, H, Bravin, A, Esteve, F, and Babot, D
- Subjects
Deterministic algorithm ,Quantitative Biology::Tissues and Organs ,Computation ,Physics::Medical Physics ,Monte Carlo method ,FIS/07 - FISICA APPLICATA (A BENI CULTURALI, AMBIENTALI, BIOLOGIA E MEDICINA) ,Statistical fluctuations ,01 natural sciences ,030218 nuclear medicine & medical imaging ,03 medical and health sciences ,0302 clinical medicine ,0103 physical sciences ,[INFO.INFO-IM]Computer Science [cs]/Medical Imaging ,Humans ,Dosimetry ,radiotherapy, fast dose calculation, ray tracing ,ComputingMilieux_MISCELLANEOUS ,Simulation ,Physics ,010308 nuclear & particles physics ,Radiotherapy Dosage ,Models, Theoretical ,Hybrid algorithm ,3. Good health ,Computational physics ,Personal computer ,Ray casting ,Monte Carlo Method ,Algorithms ,Synchrotrons - Abstract
A hybrid approach is proposed to compute the dose deposited in cancerous and healthy tissues during stereotactic synchrotron radiotherapy treatment. In this approach the computation is divided into two parts: (1) the primary dose is calculated using a deterministic algorithm based on ray casting; (2) the secondary dose (due to scattering and fluorescence) is computed using a hybrid algorithm combining Monte Carlo and a deterministic method. The results obtained for test cases are compared to those obtained with the Monte Carlo method alone (Geant4 code) and found to be in excellent agreement. The proposed simulation scheme makes it possible to simulate dose maps with a single personal computer, with computation time and statistical fluctuations substantially reduced in comparison with conventional Monte Carlo simulations. © 2007 IEEE.
- Published
- 2007
28. Synchrotron radiation computed tomography station at the ESRF biomedical beamline
- Author
-
William Thomlinson, Paul Tafforeau, Thierry Brochard, I. Tropres, H. Elleaume, Jean-François Adam, Herwig Requardt, Christian Nemoz, S. Monfraix, G. Le Duc, Alberto Bravin, Pekka Suortti, François Estève, Sam Bayat, Jani Keyriläinen, G. Berruyer, Marie-Claude Biston, Julia Rousseau, Stéphanie Corde, Manuel Fernández, Liisa Porra, S. Fiedler, Aurélie Joubert, A. M. Charvet, Paola Coan, Michel Renier, Caroline Boudou, Choi, JY, Rah, S, Nemoz, C, Bayat, S, Berruyer, G, Brochard, T, Coan, P, Le Duc, G, Keyrilainen, J, Monfraix, S, Renier, M, Requardt, H, Bravin, A, Tafforeau, P, Adam, J, Biston, M, Boudou, C, Charvet, A, Corde, S, Elleaume, H, Esteve, F, Joubert, A, Rousseau, J, Tropres, I, Fernandez, M, Porra, L, Suortti, P, Fiedler, S, and Thomlinson, W
- Subjects
medicine.medical_specialty ,genetic structures ,Synchrotron radiation ,FIS/07 - FISICA APPLICATA (A BENI CULTURALI, AMBIENTALI, BIOLOGIA E MEDICINA) ,Image processing ,Computed tomography ,Biomedical equipment ,urologic and male genital diseases ,law.invention ,Imaging modalities ,Imaging ,Optics ,law ,Medical ,otorhinolaryngologic diseases ,medicine ,Medical physics ,Tomography ,Physics ,medicine.diagnostic_test ,business.industry ,Synchrotron ,Beamline ,business ,psychological phenomena and processes - Abstract
The different tomography imaging modalities of the ESRF Medical Beamline are described and research applications are presented.
- Published
- 2007
29. Wnt-pathway inhibitors with selective activity against triple-negative breast cancer: From thienopyrimidine to quinazoline inhibitors.
- Author
-
Boudou C, Mattio L, Koval A, Soulard V, and Katanaev VL
- Abstract
The Wnt-pathway has a critical role in development and tissue homeostasis and has attracted increased attention to develop anticancer drugs due to its aberrant activation in many cancers. In this study, we identified a novel small molecule series with a thienopyrimidine scaffold acting as a downstream inhibitor of the β-catenin-dependent Wnt-pathway. This novel chemotype was investigated using Wnt-dependent triple-negative breast cancer (TNBC) cell lines. Structure activity relationship (SAR) exploration led to identification of low micromolar compounds such as 5a , 5d , 5e and a novel series with quinazoline scaffold such as 9d . Further investigation showed translation of activity to inhibit cancer survival of HCC1395 and MDA-MB-468 TNBC cell lines without affecting a non-cancerous breast epithelial cell line MCF10a. This anti-proliferative effect was synergistic to docetaxel treatment. Collectively, we identified novel chemotypes acting as a downstream inhibitor of β-catenin-dependent Wnt-pathway that could expand therapeutic options to manage TNBC., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2022 Boudou, Mattio, Koval, Soulard and Katanaev.)
- Published
- 2022
- Full Text
- View/download PDF
30. Unlocking the Wnt pathway: Therapeutic potential of selective targeting FZD 7 in cancer.
- Author
-
Larasati Y, Boudou C, Koval A, and Katanaev VL
- Subjects
- Adult, Carcinogenesis, Humans, Neoplastic Stem Cells metabolism, Frizzled Receptors metabolism, Wnt Signaling Pathway
- Abstract
The Wnt signaling is of paramount pathophysiological importance. Despite showing promising anticancer activities in pre-clinical studies, current Wnt pathway inhibitors face complications in clinical trials resulting from on-target toxicity. Hence, the targeting of pathway component(s) that are essential for cancer but dispensable for normal physiology is key to the development of a safe Wnt signaling inhibitor. Frizzled
7 (FZD7 ) is a Wnt pathway receptor that is redundant in healthy tissues but crucial in various cancers. FZD7 modulates diverse aspects of carcinogenesis, including cancer growth, metastasis, maintenance of cancer stem cells, and chemoresistance. In this review, we describe state-of-the-art knowledge of the functions of FZD7 in carcinogenesis and adult tissue homeostasis. Next, we overview the development of small molecules and biomolecules that target FZD7 . Finally, we discuss challenges and possibilities in developing FZD7 -selective antagonists., Competing Interests: Conflicts of Interest The authors declare that they have no conflict of interests., (Copyright © 2021 The Author(s). Published by Elsevier Ltd.. All rights reserved.)- Published
- 2022
- Full Text
- View/download PDF
31. Discovery and preclinical characterization of [ 18 F]PI-2620, a next-generation tau PET tracer for the assessment of tau pathology in Alzheimer's disease and other tauopathies.
- Author
-
Kroth H, Oden F, Molette J, Schieferstein H, Capotosti F, Mueller A, Berndt M, Schmitt-Willich H, Darmency V, Gabellieri E, Boudou C, Juergens T, Varisco Y, Vokali E, Hickman DT, Tamagnan G, Pfeifer A, Dinkelborg L, Muhs A, and Stephens A
- Subjects
- Animals, Brain diagnostic imaging, Brain metabolism, Fluorine Radioisotopes pharmacokinetics, Humans, Macaca mulatta, Mice, Monoamine Oxidase metabolism, Monoamine Oxidase Inhibitors pharmacokinetics, Protein Binding, Pyridines pharmacokinetics, Radiopharmaceuticals pharmacokinetics, Alzheimer Disease diagnostic imaging, Monoamine Oxidase Inhibitors chemical synthesis, Positron-Emission Tomography methods, Pyridines chemical synthesis, Radiopharmaceuticals chemical synthesis
- Abstract
Purpose: Tau deposition is a key pathological feature of Alzheimer's disease (AD) and other neurodegenerative disorders. The spreading of tau neurofibrillary tangles across defined brain regions corresponds to the observed level of cognitive decline in AD. Positron-emission tomography (PET) has proved to be an important tool for the detection of amyloid-beta (Aβ) aggregates in the brain, and is currently being explored for detection of pathological misfolded tau in AD and other non-AD tauopathies. Several PET tracers targeting tau deposits have been discovered and tested in humans. Limitations have been reported, especially regarding their selectivity., Methods: In our screening campaign we identified pyrrolo[2,3-b:4,5-c']dipyridine core structures with high affinity for aggregated tau. Further characterization showed that compounds containing this moiety had significantly reduced monoamine oxidase A (MAO-A) binding compared to pyrido[4,3-b]indole derivatives such as AV-1451., Results: Here we present preclinical data of all ten fluoropyridine regioisomers attached to the pyrrolo[2,3-b:4,5-c']dipyridine scaffold, revealing compounds 4 and 7 with superior properties. The lead candidate [
18 F]PI-2620 (compound 7) displayed high affinity for tau deposits in AD brain homogenate competition assays. Specific binding to pathological misfolded tau was further demonstrated by autoradiography on AD brain sections (Braak I-VI), Pick's disease and progressive supranuclear palsy (PSP) pathology, whereas no specific tracer binding was detected on brain slices from non-demented donors. In addition to its high affinity binding to tau aggregates, the compound showed excellent selectivity with no off-target binding to Aβ or MAO-A/B. Good brain uptake and fast washout were observed in healthy mice and non-human primates., Conclusions: Therefore, [18 F]PI-2620 was selected for clinical validation.- Published
- 2019
- Full Text
- View/download PDF
32. Normoxic polyacrylamide gel doped with iodine: response versus X-ray energy.
- Author
-
Gastaldo J, Boudou C, Lamalle L, Troprès I, Corde S, Sollier A, Rucka G, and Elleaume H
- Subjects
- Computer Simulation, Dose-Response Relationship, Radiation, Gels chemistry, Gels radiation effects, Linear Energy Transfer, Radiation Dosage, Acrylic Resins chemistry, Acrylic Resins radiation effects, Iodine chemistry, Iodine radiation effects, Models, Chemical, Synchrotrons
- Abstract
The basis of Synchrotron Stereotactic Radio-Therapy (SSRT) is the incorporation of high atomic number atoms (iodine, for example) into the tumour mass followed by an irradiation with a monochromatic, low energy, X-ray beam from a synchrotron source. The purpose of the present study was to determine whether polymer gel dosimetry could be used to measure the enhancement of absorbed energy induced by the iodine in the media. We have used a standard nPAG formulation, loaded with NaI and the irradiations were performed either with monochromatic X-rays at the ESRF medical beamline or with a conventional 6 MV X-ray beam from a linear accelerator at the Grenoble University Hospital. We observed sensitivity increase with iodine loaded gels irradiated at low energies, in good agreement with the theoretical iodine dose-enhancement. As expected, the response of the iodine-doped polymer gel was not increased after irradiation with mega-voltage X-rays. We demonstrate in this study that polymer gel dosimeters can be used for measuring dose-enhancement due to iodine presence in SSR treatment.
- Published
- 2008
- Full Text
- View/download PDF
33. Enhanced survival and cure of F98 glioma-bearing rats following intracerebral delivery of carboplatin in combination with photon irradiation.
- Author
-
Rousseau J, Boudou C, Barth RF, Balosso J, Estève F, and Elleaume H
- Subjects
- Animals, Combined Modality Therapy, Glioma mortality, Glioma pathology, Humans, Male, Rats, Rats, Inbred F344, Antineoplastic Agents administration & dosage, Carboplatin administration & dosage, Glioma drug therapy, Photons therapeutic use
- Abstract
Purpose: The goal of the present study was to evaluate the efficacy of intracerebral (i.c.) administration of carboplatin by means of convection-enhanced delivery (CED) in combination with fractionated, external beam photon irradiation for the treatment of F98 glioma-bearing rats., Experimental Design: Carboplatin (20 microg/20 microL) was administrated i.c. by CED to F98 glioma-bearing rats, 13 days after stereotactic implantation of 10(3) tumor cells. One day following initiation of CED, a 24-Gy X-ray dose was administered in three daily fractions of 8 Gy each. Photon irradiation was carried out using either a conventional (6 MV) linear accelerator or a monochromatic synchrotron source (80 keV) at the European Synchrotron Radiation Facility. The primary end point of this study was overall survival., Results: The median survival times were 79 and 60 days and the corresponding percent increase in life spans were 182% and 114%, respectively, for the combination of carboplatin chemotherapy and irradiation with either 6-MV or 80-keV photons. A subset of long-term survivors (>200 days) were observed in both chemoradiotherapy groups: 16.6% and 8.3% for 6 MV and 80 keV, respectively. In contrast, the median survival times for 6-MV or 80-keV irradiated controls, chemotherapy alone, and untreated controls were 42, 51, 45, and 28 days, respectively., Conclusions: Our results convincingly show the therapeutic efficacy of i.c. administration of carboplatin by means of CED in combination with either 6-MV or 80-keV photons. Further studies are warranted to optimize this combination of chemoradiotherapy for malignant gliomas.
- Published
- 2007
- Full Text
- View/download PDF
34. Trans-(+/-)-2-tert-butyl-3-phenyloxaziridine: a unique reagent for the oxidation of thiolates into sulfenates.
- Author
-
Boudou C, Bergès M, Sagnes C, Sopková-de Oliveira Santos J, Perrio S, and Metzner P
- Subjects
- Aziridines chemistry, Molecular Structure, Oxidation-Reduction, Sulfenic Acids chemistry, Aziridines chemical synthesis, Sulfenic Acids chemical synthesis, Sulfhydryl Compounds chemistry
- Abstract
Aliphatic thiolates were efficiently converted into the corresponding sulfenates by smooth oxidation with trans-(+/-)-2-tert-butyl-3-phenyloxaziridine at room temperature (five examples). Subsequent electrophilic quench with benzyl bromide led to sulfoxides (S-alkylation) in good to moderate yields. Application of the protocol to an aromatic substrate was also successful. This work represents the first valuable example of the use of this poorly active oxidizing agent in synthetic organic chemistry without the need for activating conditions.
- Published
- 2007
- Full Text
- View/download PDF
35. Convection-enhanced delivery of an iodine tracer into rat brain for synchrotron stereotactic radiotherapy.
- Author
-
Rousseau J, Boudou C, Estève F, and Elleaume H
- Subjects
- Animals, Brain drug effects, Brain Neoplasms diagnosis, Contrast Media administration & dosage, Glioma diagnosis, Injections, Intralesional methods, Male, Radiometry methods, Radiotherapy Dosage, Rats, Rats, Inbred F344, Synchrotrons, Brain surgery, Brain Neoplasms radiotherapy, Glioma radiotherapy, Iopamidol administration & dosage, Radiosurgery methods
- Abstract
Purpose: To evaluate direct intracerebral and intratumoral iodine delivery as means to improve iodine distribution for synchrotron stereotactic radiotherapy (SSR) and to evaluate the corresponding X-ray dose distribution., Methods and Materials: Healthy rats and F98 glioma-bearing rats received an iodinated contrast agent (iopamidol) intracerebrally either by bolus injection (5 microL over approximately 1 min) or by convection-enhanced delivery (infusion volumes of 5, 10, and 20 microL at a rate of 0.5 microL/min). We used synchrotron computed tomography (CT) to determine the iodine distribution after completion of infusion and a Monte Carlo code to compute the resulting radiation dose in SSR., Results: Post-infusion CT imaging revealed high iodine concentrations in the perfused area with both injection methods. The iodine concentration remained elevated, with an exponential decay time constant of approximately 50 min, well suited for SSR treatment. Convection-enhanced delivery was shown to provide more uniform and controlled volumes of distribution than bolus injection and was chosen to evaluate the corresponding X-ray dose distribution. Sharp dose gradients around the target and excellent sparing of the contralateral brain were achievable with low iodine concentrations in the surrounding healthy brain tissues and blood vessels., Conclusions: Convection-enhanced delivery is an effective method to deliver high iodine concentrations and could improve the outcome of iodine-enhanced SSR.
- Published
- 2007
- Full Text
- View/download PDF
36. Fast dose calculation for stereotactic synchrotron radiotherapy.
- Author
-
Freud N, Létang JM, Mary C, Boudou C, Ferrero C, Elleaume H, Bravin A, Estève F, and Babot D
- Subjects
- Humans, Monte Carlo Method, Algorithms, Models, Theoretical, Radiotherapy Dosage, Synchrotrons
- Abstract
A hybrid approach is proposed to compute the dose deposited in cancerous and healthy tissues during stereotactic synchrotron radiotherapy treatment. In this approach the computation is divided into two parts: (1) the primary dose is calculated using a deterministic algorithm based on ray casting; (2) the secondary dose (due to scattering and fluorescence) is computed using a hybrid algorithm combining Monte Carlo and a deterministic method. The results obtained for test cases are compared to those obtained with the Monte Carlo method alone (Geant4 code) and found to be in excellent agreement. The proposed simulation scheme makes it possible to simulate dose maps with a single personal computer, with computation time and statistical fluctuations substantially reduced in comparison with conventional Monte Carlo simulations.
- Published
- 2007
- Full Text
- View/download PDF
37. Monte Carlo dosimetry for synchrotron stereotactic radiotherapy of brain tumours.
- Author
-
Boudou C, Balosso J, Estève F, and Elleaume H
- Subjects
- Computer Simulation, Feasibility Studies, Humans, Models, Statistical, Monte Carlo Method, Radiation Dosage, Synchrotrons, Brain Neoplasms diagnostic imaging, Brain Neoplasms radiotherapy, Models, Biological, Radiographic Image Interpretation, Computer-Assisted methods, Radiometry methods, Radiosurgery methods, Radiotherapy Planning, Computer-Assisted methods
- Abstract
A radiation dose enhancement can be obtained in brain tumours after infusion of an iodinated contrast agent and irradiation with kilovoltage x-rays in tomography mode. The aim of this study was to assess dosimetric properties of the synchrotron stereotactic radiotherapy technique applied to humans (SSR) for preparing clinical trials. We designed an interface for dose computation based on a Monte Carlo code (MCNPX). A patient head was constructed from computed tomography (CT) data and a tumour volume was modelled. Dose distributions were calculated in SSR configuration for various energy beam and iodine content in the target volume. From the calculations, it appears that the iodine-filled target (10 mg ml(-1)) can be efficiently irradiated by a monochromatic beam of energy ranging from 50 to 85 keV. This paper demonstrates the feasibility of stereotactic radiotherapy for treating deep-seated brain tumours with monoenergetic x-rays from a synchrotron.
- Published
- 2005
- Full Text
- View/download PDF
38. Irradiation in presence of iodinated contrast agent results in radiosensitization of endothelial cells: consequences for computed tomography therapy.
- Author
-
Joubert A, Biston MC, Boudou C, Ravanat JL, Brochard T, Charvet AM, Estève F, Balosso J, and Foray N
- Subjects
- Animals, Cattle, Chromatography, High Pressure Liquid methods, Contrast Media chemistry, Contrast Media radiation effects, DNA radiation effects, DNA Damage drug effects, DNA-Activated Protein Kinase, DNA-Binding Proteins metabolism, Endothelium, Vascular cytology, Iopamidol chemistry, Iopamidol pharmacology, Iopamidol radiation effects, Protein Serine-Threonine Kinases metabolism, Radiation Tolerance physiology, Synchrotrons, Contrast Media pharmacology, DNA Repair drug effects, DNA Repair radiation effects, Endothelium, Vascular radiation effects, Iopamidol analogs & derivatives, Radiation Tolerance drug effects
- Abstract
Purpose: To date, iodinated contrast agents (ICA) are commonly used in medical imaging to improve tumor visualization by attenuating scanners X-rays. However, some adverse reactions to ICAs are still reported, and their molecular origin remains unclear. In 1983, it was proposed to visualize and treat ICA-loaded tumors by using scanners as therapy machines to enhance X-rays absorption at the iodine atoms. Theoretically, such physical conditions are optimized at 50 keV and can be easily obtained with synchrotrons., Methods and Materials: Here, we examined the molecular and cellular responses of mammalian endothelial cells to radiation in the presence of iomeprol, one of the most extensively used ICAs., Results: Irradiation with X-rays at 50 keV in the presence of iomeprol produced a strong radiosensitization effect. The same conclusion was reached with a standard medical irradiator but to a lesser extent. While such treatment did not produce additional DNA double-strand breaks, we observed a dose-dependent production of iodides due to the iomeprol radiolysis that inhibit double-strand break repair rate by decreasing DNA-PK kinase activity., Conclusions: Our data suggest that the concomitant use of ICA and radiation may be toxic when radiation-produced iodide concentrations and double-strand break yields are sufficient. The potential toxicity of ICAs during X-rays for diagnosis and therapy is discussed.
- Published
- 2005
- Full Text
- View/download PDF
39. Remarkably mild and simple preparation of sulfenate anions from beta-sulfinylesters: a new route to enantioenriched sulfoxides.
- Author
-
Caupène C, Boudou C, Perrio S, and Metzner P
- Abstract
[reaction: see text] A general, efficient, and experimentally simple method for the generation of sulfenate salts has been developed using beta-sulfinylesters as substrates. The process is based on a retro-Michael reaction, initiated by deprotonation at low temperature. Upon treatment with alkyl halides, the liberated sulfenates are subsequently converted into sulfoxides in good to excellent yield. Extension of the methodology to an unprecedented access to nonracemic sulfoxides by introduction of an enantiopure ligand, (-)-sparteine, is also described.
- Published
- 2005
- Full Text
- View/download PDF
40. Synchrotron stereotactic radiotherapy: dosimetry by Fricke gel and Monte Carlo simulations.
- Author
-
Boudou C, Biston MC, Corde S, Adam JF, Ferrero C, Estève F, and Elleaume H
- Subjects
- Calibration, Dose-Response Relationship, Radiation, Gels, Ions, Magnetic Resonance Spectroscopy, Monte Carlo Method, Phantoms, Imaging, Photons, Radiation Dosage, Radiometry, Radiotherapy Dosage, Radiotherapy Planning, Computer-Assisted methods, Water, X-Rays, Radiosurgery methods, Synchrotrons
- Abstract
Synchrotron stereotactic radiotherapy (SSR) consists in loading the tumour with a high atomic number element (Z), and exposing it to monochromatic x-rays from a synchrotron source (50-100 keV), in stereotactic conditions. The dose distribution results from both the stereotactic monochromatic x-ray irradiation and the presence of the high Z element. The purpose of this preliminary study was to evaluate the two-dimensional dose distribution resulting solely from the irradiation geometry, using Monte Carlo simulations and a Fricke gel dosimeter. The verification of a Monte Carlo-based dosimetry was first assessed by depth dose measurements in a water tank. We thereafter used a Fricke dosimeter to compare Monte Carlo simulations with dose measurements. The Fricke dosimeter is a solution containing ferrous ions which are oxidized to ferric ions under ionizing radiation, proportionally to the absorbed dose. A cylindrical phantom filled with Fricke gel was irradiated in stereotactic conditions over several slices with a continuous beam (beam section = 0.1 x 1 cm2). The phantom and calibration vessels were then imaged by nuclear magnetic resonance. The measured doses were fairly consistent with those predicted by Monte Carlo simulations. However, the measured maximum absolute dose was 10% underestimated regarding calculation. The loss of information in the higher region of dose is explained by the diffusion of ferric ions. Monte Carlo simulation is the most accurate tool for dosimetry including complex geometries made of heterogeneous materials. Although the technique requires improvements, gel dosimetry remains an essential tool for the experimental verification of dose distribution in SSR with millimetre precision.
- Published
- 2004
- Full Text
- View/download PDF
Catalog
Discovery Service for Jio Institute Digital Library
For full access to our library's resources, please sign in.