title: Measurement of dynamic wedge angles and beam profiles by means of MRI ferrous sulphate gel dosimetry.
abstract: The purpose of this study is to examine the possible value of measuring the dose distribution in dynamic wedge photon beams using ferrous sulphate gel phantoms analysed by MRI. The wedge angles and dose profiles were measured for a field size of 70 x 70 mm2 and for dynamic wedge angles of 15 degrees, 30 degrees, 45 degrees and 60 degrees using a 15 MV photon beam generated from a Clinac 2100 CD (Varian). The dose profiles obtained from MRI ferrous sulphate gel were in good agreement with the dose measurements performed with a diode detector array. Also, the wedge angles determined from the MRI ferrous sulphate gel agreed well with the values obtained by using film dosimetry and with calculations by use of TMS (treatment planning system) (Helax, Uppsala, Sweden). The study demonstrated that MRI ferrous sulphate gel dosimetry is an adequate tool for measurements of some beam characteristics of dynamic radiation fields.
authors: Department of Medical Physics, Norwegian Radium Hospital, Montebello, Oslo, Norway.
authors: M
authors: M
authors: Bengtsson
authors: T
authors: T
authors: Furre
authors: J
authors: J
authors: Rødal
authors: A
authors: A
authors: Skretting
authors: D R
authors: DR
authors: Olsen
mesh_terms: D000465:Algorithms; D004307:Dose-Response Relationship, Radiation; D005296:Ferrous Compounds; D005782:Gels; D006801:Humans; D008279:Magnetic Resonance Imaging; D009682:Magnetic Resonance Spectroscopy; D008433:Mathematics; D019047:Phantoms, Imaging; D017785:Photons
chemical_list: D005296:Ferrous Compounds; D005782:Gels; C020748:ferrous sulfate