Search results for "Poly-vinyl alcohol"

showing 3 items of 3 documents

Novel GTA-PVA Fricke gels for three-dimensional dose mapping in radiotherapy

2017

Abstract One of the most recent and promising developments in radiotherapy dosimetry was the introduction of 3D radiation-sensitive gels. These gels present tissue equivalent composition and density, so they also serve as phantoms, and their response is largely independent of radiation quality and dose rate. Some gels are infused with ferrous sulfate and rely on the radiation-induced oxidation of ferrous ions to ferric ions (Fricke-gels). These formulations suffer from spontaneous-oxidation and diffusion of ferric ions after irradiation; chelating agents such as xylenol-orange significantly reduces the latter. Other gel types consist of dispersed monomers, and rely on radiation-induced cros…

Materials scienceDiffusionThree-dimensional dosimetry Poly-vinyl alcohol Glutaraldehyde Ferrous sulfate Xylenol-orange Spectrophotometry Optical tomography Magnetic resonance imagingFerrous sulfate01 natural sciencesGlutaraldehyde030218 nuclear medicine & medical imagingFerrousThree-dimensional dosimetry03 medical and health scienceschemistry.chemical_compound0302 clinical medicineMagnetic resonance imaging0103 physical sciencesmedicineChelationIrradiationInstrumentationchemistry.chemical_classificationPoly-vinyl alcoholOptical tomographyRadiation010308 nuclear & particles physicsPolymerXylenol-orangeMonomerchemistryChemical engineeringSpectrophotometryFerricGlutaraldehydeFerrous sulfate; Glutaraldehyde; Magnetic resonance imaging; Optical tomography; Poly-vinyl alcohol; Spectrophotometry; Three-dimensional dosimetry; Xylenol-orange; Radiation; Instrumentationmedicine.drugNuclear chemistry
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Analysis of the response of PVA-GTA Fricke-gel dosimeters with clinical magnetic resonance imaging

2018

Abstract Fricke gel dosimeters produced with a matrix of Poly-vinyl alcohol (PVA) cross-linked with glutaraldehyde (GTA) were analyzed with magnetic resonance imaging (MRI). Previous studies based on spectrophotometry showed valuable dosimetric features of these gels in terms of X-ray sensitivity and diffusion of the ferric ions produced after irradiation. In this study, MRI was performed on the gels at 1.5 T with a clinical scanner in order to optimize the acquisition parameters and obtain high contrast between irradiated and non-irradiated samples. The PVA gels were found to offer good linearity in the range of 0–10 Gy and a stable signal for several hours after irradiation. The sensitivi…

Nuclear and High Energy PhysicsXylenol orangeMaterials scienceSettore ING-IND/20 - Misure E Strumentazione NucleariDose profileGlutaraldehydeImaging phantom030218 nuclear medicine & medical imagingMatrix (chemical analysis)Gel dosimeter03 medical and health scienceschemistry.chemical_compoundMagnetic resonance imaging0302 clinical medicineNuclear magnetic resonanceIrradiationGlutaraldehydeùInstrumentationPoly-vinyl alcoholX-ray radiotherapyDosimeterSettore FIS/01 - Fisica SperimentaleSettore FIS/07 - Fisica Applicata(Beni Culturali Ambientali Biol.e Medicin)chemistry030220 oncology & carcinogenesisIonization chamberAgaroseGel dosimeter; Glutaraldehyde; Magnetic resonance imaging; Poly-vinyl alcohol; X-ray radiotherapy; Nuclear and High Energy Physics; InstrumentationSettore MED/36 - Diagnostica Per Immagini E RadioterapiaNuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms
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Hydrogels for Three-Dimensional Ionizing-Radiation Dosimetry

2021

Radiation-sensitive gels are among the most recent and promising developments for radiation therapy (RT) dosimetry. RT dosimetry has the twofold goal of ensuring the quality of the treatment and the radiation protection of the patient. Benchmark dosimetry for acceptance testing and commissioning of RT systems is still based on ionization chambers. However, even the smallest chambers cannot resolve the steep dose gradients of up to 30–50% per mm generated with the most advanced techniques. While a multitude of systems based, e.g., on luminescence, silicon diodes and radiochromic materials have been developed, they do not allow the truly continuous 3D dose measurements offered by radiation-se…

xylenol-orangeMaterials sciencePolymers and Plasticspoly-vinyl alcoholScienceDose profileBioengineeringGeneral. Including alchemyReviewRadiation01 natural sciences030218 nuclear medicine & medical imagingIonizing radiationBiomaterials03 medical and health sciencesMagnetic resonance imaging0302 clinical medicineQD1-650103 physical sciencesthree-dimensional dosimetryDosimetryIrradiationQD1-999QD146-197Optical tomography010308 nuclear & particles physicsbusiness.industryOrganic ChemistryQpolyacrylamide gelChemistrySpectrophotometryAbsorbed doseglutaraldehydeRadiation protectionLuminescencebusinessInorganic chemistryBiomedical engineeringferrous sulfateGels
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