title: Validation of MR-based polymer gel dosimetry as a preclinical three-dimensional verification tool in conformal radiotherapy.
abstract: The aim of this work was to investigate MR-based polymer gel dosimetry as a three-dimensional (3D) dosimetry technique in conformal radiotherapy. A cylindrical container filled with polymer gel was placed in a water-filled torso phantom to verify a treatment plan for the conformal irradiation of a mediastinal tumor located near the esophagus. Magnetic resonance spin-spin relaxation rate images were acquired and, after calibration, converted to absorbed dose distributions. The dose maps were compared with dose distributions measured using radiographic film. The average root-mean-square structural deviation, for the complete dose distribution, amounted to less than 3% between gel and film dose maps. It may be expected that MR gel dosimetry will become a valuable tool in the verification of 3D dose distributions. The influence of imaging artifacts arising from eddy currents, temperature drift during scanning, and B1 field inhomogeneity on the dose maps was taken into account and minimized.
authors.affiliation: MR Department, University Hospital of Ghent, Belgium. Yves.DeDeene@rug.ac.be
authors.forename: Y
authors.initials: Y
authors.lastname: De Deene
authors.forename: C
authors.initials: C
authors.lastname: De Wagter
authors.forename: B
authors.initials: B
authors.lastname: Van Duyse
authors.forename: S
authors.initials: S
authors.lastname: Derycke
authors.forename: B
authors.initials: B
authors.lastname: Mersseman
authors.forename: W
authors.initials: W
authors.lastname: De Gersem
authors.forename: T
authors.initials: T
authors.lastname: Voet
authors.forename: E
authors.initials: E
authors.lastname: Achten
authors.forename: W
authors.initials: W
authors.lastname: De Neve
mesh_terms: D020106:Acrylamide; D004307:Dose-Response Relationship, Radiation; D005782:Gels; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008954:Models, Biological; D019047:Phantoms, Imaging; D011108:Polymers; D011829:Radiation Dosage; D011834:Radiation Monitoring; D011880:Radiotherapy Planning, Computer-Assisted / Q000295:instrumentation / Q000379:methods*; D020266:Radiotherapy, Conformal / Q000295:instrumentation / Q000379:methods*; D015203:Reproducibility of Results
chemical_list: D005782:Gels; D011108:Polymers; D020106:Acrylamide