title: Polymer gel dosimetry using a three-dimensional MRI acquisition technique.
abstract: In this work, three-dimensional (3-D) MRI techniques are employed in N-Vinylpyrrolidone-Argon-(VIPAR-) based polymer gel dosimetry. VIPAR gels were irradiated using a Nucletron microSelection 192Ir HDR brachytherapy remote afterloading system with single source dwell position and intravascular brachytherapy irradiation protocols. A single VIPAR gel and a single irradiation are adequate to obtain the full calibration curve needed. The 3-D dose distributions obtained with the 3-D MRI method were found to be in good agreement with the corresponding Monte Carlo calculations, for brachytherapy and intravascular irradiations. The method allows the reconstruction of isodose contours over any plane, with increased spatial resolution and accuracy following a single MR acquisition. VIPAR gel measurements using a 3-D MRI readout technique can be of particular use in the experimental dosimetry of brachytherapy sources, as well as for dose verification purposes when complex irradiation regimes and three-dimensional dose gradients are investigated.
authors.affiliation: MR Clinical Science, Philips Hellas Medical Systems, 14 Sarantaporou str & Metonos str., 155 61 Cholargos, Athens, Greece. panagiotis.mparas@philips.com
authors.forename: P
authors.initials: P
authors.lastname: Baras
authors.forename: I
authors.initials: I
authors.lastname: Seimenis
authors.forename: P
authors.initials: P
authors.lastname: Kipouros
authors.forename: P
authors.initials: P
authors.lastname: Papagiannis
authors.forename: A
authors.initials: A
authors.lastname: Angelopoulos
authors.forename: L
authors.initials: L
authors.lastname: Sakelliou
authors.forename: E
authors.initials: E
authors.lastname: Pappas
authors.forename: D
authors.initials: D
authors.lastname: Baltas
authors.forename: P
authors.initials: P
authors.lastname: Karaiskos
authors.forename: P
authors.initials: P
authors.lastname: Sandilos
authors.forename: L
authors.initials: L
authors.lastname: Vlachos
mesh_terms: D001128:Argon; D001918:Brachytherapy / Q000295:instrumentation / Q000379:methods*; D002138:Calibration; D004867:Equipment Design; D005780:Gelatin; D005782:Gels; D006801:Humans; D021621:Imaging, Three-Dimensional / Q000295:instrumentation / Q000379:methods*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D019047:Phantoms, Imaging; D011108:Polymers; D011145:Polyvinyls; D011874:Radiometry / Q000295:instrumentation / Q000379:methods*; D011879:Radiotherapy Dosage; D011880:Radiotherapy Planning, Computer-Assisted / Q000295:instrumentation / Q000379:methods*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D014652:Vascular Diseases / Q000532:radiotherapy
chemical_list: D005782:Gels; C474491:N-vinylpyrrolidone-argon polymer; D011108:Polymers; D011145:Polyvinyls; D001128:Argon; D005780:Gelatin