title: Normoxic polyacrylamide gel doped with iodine: response versus X-ray energy.
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.
authors.affiliation: Institut National de la Santé et de la Recherche Médicale, Unité 836, Grenoble Institut des Neurosciences, Equipe Rayonnement synchrotron et recherche médicale, Grenoble F-38043, Cedex 9, France. Gastaldo.jerome@free.fr
authors.forename: Jérôme
authors.initials: J
authors.lastname: Gastaldo
authors.forename: Caroline
authors.initials: C
authors.lastname: Boudou
authors.forename: Laurent
authors.initials: L
authors.lastname: Lamalle
authors.forename: Irène
authors.initials: I
authors.lastname: Troprès
authors.forename: Stéphanie
authors.initials: S
authors.lastname: Corde
authors.forename: Albéric
authors.initials: A
authors.lastname: Sollier
authors.forename: Günther
authors.initials: G
authors.lastname: Rucka
authors.forename: Hélène
authors.initials: H
authors.lastname: Elleaume
mesh_terms: D000180:Acrylic Resins / Q000737:chemistry* / Q000528:radiation effects*; D003198:Computer Simulation; D004307:Dose-Response Relationship, Radiation; D005782:Gels / Q000737:chemistry / Q000528:radiation effects; D007455:Iodine / Q000737:chemistry* / Q000528:radiation effects*; D018499:Linear Energy Transfer; D008956:Models, Chemical; D011829:Radiation Dosage; D017356:Synchrotrons; D000099166:Polyacrylamides
chemical_list: D000180:Acrylic Resins; D005782:Gels; D007455:Iodine; D000099166:Polyacrylamides