1. Sensitivity variation of doped Fricke gel irradiated with monochromatic synchrotron X rays between 33.5 and 80 keV
- Author
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Jean-François Le Bas, Marie-Claude Biston, Jacques Balosso, Anne-Marie Charvet, François Estève, Aurélie Joubert, Hélène Elleaume, Stéphanie Corde, Jean-François Adam, Serduc, Raphael, Rayonnement Synchrotron et Recherche Medicale (RSRM), European Synchrotron Radiation Facility (ESRF)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut National de la Santé et de la Recherche Médicale (INSERM), Service d'Imagerie par Résonance Magnétique (IRM), CHU Grenoble, Département de cancérologie et radiothérapie, and Université Joseph Fourier - Grenoble 1 (UJF)-European Synchrotron Radiation Facility (ESRF)-Institut National de la Santé et de la Recherche Médicale (INSERM)
- Subjects
Magnetic Resonance Spectroscopy ,030218 nuclear medicine & medical imaging ,law.invention ,0302 clinical medicine ,law ,Neoplasms ,MESH: Neoplasms ,MESH: Radiotherapy Dosage ,MESH: Radiotherapy Planning, Computer-Assisted ,Radiation ,Radiological and Ultrasound Technology ,Relaxation (NMR) ,Radiotherapy Dosage ,Barium ,General Medicine ,Photoelectric effect ,MESH: Iothalamic Acid ,Synchrotron ,030220 oncology & carcinogenesis ,Calibration ,MESH: Synchrotrons ,MESH: Radiation Dosage ,MESH: Ions ,Materials science ,MESH: Gels ,MESH: Barium Sulfate ,chemistry.chemical_element ,Radiation Dosage ,MESH: Calibration ,Ion ,MESH: X-Rays ,03 medical and health sciences ,MESH: Dose-Response Relationship, Radiation ,Radiology, Nuclear Medicine and imaging ,Irradiation ,Radiometry ,Ions ,MESH: Magnetic Resonance Spectroscopy ,business.industry ,Radiotherapy Planning, Computer-Assisted ,X-Rays ,Radiochemistry ,MESH: Radiometry ,Public Health, Environmental and Occupational Health ,Dose-Response Relationship, Radiation ,Iothalamic Acid ,chemistry ,Monochromatic color ,Barium Sulfate ,Nuclear medicine ,business ,Gels ,Synchrotrons - Abstract
International audience; An experimental binary radiotherapy proposes the concomitant use of a high-Z compound and synchrotron X rays for enhancing radiation dose selectively in tumours by a photoelectric effect. This study aimed at measuring the resulting dose enhancement in irradiated material. A doped Fricke gel dosemeter model was manufactured with 10 mg ml(-1) of iodine (Telebrix) or barium (Micropaque). Samples were irradiated with a monochromatic synchrotron beam at 33.5, 50, 65 and 80 keV. The ensuing enhancement of the sensitivity of the dosemeter was derived from the nuclear magnetic resonance relaxation rates measured at different X-ray doses. Our results demonstrate (1) the preservation of a linear relationship between relaxation rates and X-ray doses for dosemeters doped with high-Z atoms and (2) a clear energy-dependent sensitivity enhancement for barium-doped Fricke gels. This enhancement was neither reproducible with iodinated compounds nor clearly related to the expected dose enhancement factor. However 1% barium sulphate in the gel could significantly improve the gel's response when it was irradiated by low-energy X rays.
- Published
- 2005