title: Absorbed dose measurements in the build-up region of flattened versus unflattened megavoltage photon beams.
abstract: This study evaluated absorbed dose measurements in the build-up region of conventional (FF) versus flattening filter-free (FFF) photon beams. The absorbed dose in the build-up region of static 6 and 10MV FF and FFF beams was measured using radiochromic film and extrapolation chamber dosimetry for single beams with a variety of field sizes, shapes and positions relative to the central axis. Removing the flattening filter generally resulted in slightly higher relative build-up doses. No considerable impact on the depth of maximum dose was found.
authors.affiliation: Department of Radiation Oncology and Experimental Cancer Research, Ghent University, Ghent, Belgium. Electronic address: Annemieke.DePuysseleyr@UGent.be.
authors.forename: Annemieke
authors.initials: A
authors.lastname: De Puysseleyr
authors.affiliation: Department of Radiation Oncology, Medical University of Vienna/AKH Wien, Vienna, Austria; Christian Doppler Laboratory for Medical Radiation Research for Radiation Oncology, Medical University of Vienna, Vienna, Austria.
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Lechner
authors.affiliation: Department of Radiation Oncology and Experimental Cancer Research, Ghent University, Ghent, Belgium.
authors.forename: Wilfried
authors.initials: W
authors.lastname: De Neve
authors.affiliation: Department of Radiation Oncology, Medical University of Vienna/AKH Wien, Vienna, Austria; Christian Doppler Laboratory for Medical Radiation Research for Radiation Oncology, Medical University of Vienna, Vienna, Austria.
authors.forename: Dietmar
authors.initials: D
authors.lastname: Georg
authors.affiliation: Department of Radiation Oncology and Experimental Cancer Research, Ghent University, Ghent, Belgium.
authors.forename: Carlos
authors.initials: C
authors.lastname: De Wagter
mesh_terms: D065638:Absorption, Radiation; D003198:Computer Simulation; D005374:Filtration / Q000379:methods*; D006801:Humans; D008962:Models, Theoretical; D017785:Photons / Q000627:therapeutic use*; D011874:Radiometry / Q000379:methods; D011879:Radiotherapy Dosage; D011880:Radiotherapy Planning, Computer-Assisted / Q000379:methods*; D011882:Radiotherapy, High-Energy / Q000379:methods*; D015203:Reproducibility of Results; D012542:Scattering, Radiation; D012680:Sensitivity and Specificity
keywords: Ausgleichsfilterfreie Photonenstrahlung; Dosis in der Aufbauregion; Flattening filter-free; build-up dose; surface dose