title: Investigation and analysis of ferrous sulfate polyvinyl alcohol (PVA) gel dosimeter.
abstract: Ferrous sulfate (Fe(SO4)2) PVA gels were investigated for a range of absorbed doses up to 20 Gy using both magnetic resonance imaging (MRI) and spectrophotometry to determine R1 and optical density (OD) dose responses and G values. It was found that R1- and OD-dose sensitivities increased with O2 saturation or by the introduction of a freeze-thaw cycle during preparation of the PVA gel. The storage temperature of the Fe(SO4)2 PVA gel at -18 degrees C increased R1-dose sensitivity above that of gels stored at 5 degrees C. The addition of sucrose to the formulation was found to result in the largest increase in both R1- and OD-dose sensitivities. Fe(SO4)2 PVA gel with and without the addition of xylenol orange was demonstrated to have a G value of approximately 20 ions/100 eV and with sucrose approximately 24 ions/100 eV.
authors.affiliation: Centre for Medical, Health and Environmental Physics, Queensland University of Technology, Brisbane, Queensland 4000, Australia.
authors.forename: Brendan
authors.initials: B
authors.lastname: Hill
authors.forename: Sven A J
authors.initials: SA
authors.lastname: Bäck
authors.forename: Martin
authors.initials: M
authors.lastname: Lepage
authors.forename: John
authors.initials: J
authors.lastname: Simpson
authors.forename: Brendan
authors.initials: B
authors.lastname: Healy
authors.forename: Clive
authors.initials: C
authors.lastname: Baldock
mesh_terms: D002138:Calibration; D004305:Dose-Response Relationship, Drug; D004587:Electrophoresis, Agar Gel; D005296:Ferrous Compounds / Q000737:chemistry*; D005780:Gelatin / Q000737:chemistry; D005782:Gels; D007501:Iron / Q000494:pharmacology; D008279:Magnetic Resonance Imaging / Q000379:methods; D010100:Oxygen / Q000378:metabolism; D010636:Phenols; D011142:Polyvinyl Alcohol / Q000737:chemistry*; D011874:Radiometry / Q000379:methods*; D012685:Sepharose / Q000737:chemistry; D013053:Spectrophotometry / Q000379:methods; D013395:Sucrose / Q000494:pharmacology; D013454:Sulfoxides; D013696:Temperature; D014466:Ultraviolet Rays; D014992:Xylenes / Q000494:pharmacology
chemical_list: D005296:Ferrous Compounds; D005782:Gels; D010636:Phenols; D013454:Sulfoxides; D014992:Xylenes; C020748:ferrous sulfate; D013395:Sucrose; D005780:Gelatin; D011142:Polyvinyl Alcohol; D012685:Sepharose; D007501:Iron; C016833:xylenol orange; D010100:Oxygen