title: Clinical implementation and range evaluation of in vivo PET dosimetry for particle irradiation in patients with primary glioma.
abstract: OBJECTIVE
  The physical and biological properties of ion-beams offer various advantages in comparison to conventional radiotherapy, though uncertainties concerning quality assurance are still left. Due to the inverted depth dose profile, range accuracy is of paramount importance. We investigated the range deviations between planning simulation and post-fractional PET/CT measurement from particle therapy in primary glioblastoma.
  
  
  METHODS
  20 patients with glioblastoma undergoing particle therapy at our institution were selected. 10 received a proton-boost, 10 a carbon-ion-boost in addition to standard treatment. After two fractions, we performed a PET/CT-scan of the brain. We compared the resulting range deviation based on the Most-likely-shift method between the two measurements, and the measurements with corresponding expectations, calculated with the Monte-Carlo code FLUKA.
  
  
  RESULTS
  A patient's two measurements deviated by 0.7mm (±0.7mm). Overall comparison between measurements and simulation resulted in a mean range deviation of 3.3mm (±2.2mm) with significant lower deviations in the (12)C-arm.
  
  
  CONCLUSIONS
  The used planning concepts display the actual dose distributions adequately. The carbon ion group's results are below the used PTV safety margins (3mm). Further adjustments to the simulation are required for proton irradiations. Some anatomical situations require particular attention to ensure highest accuracy and safety.
authors.affiliation: University Hospital of Heidelberg, Department of Radiation Oncology, Heidelberg, Germany. Electronic address: sebastian.nischwitz@t-online.de.
authors.forename: Sebastian P
authors.initials: SP
authors.lastname: Nischwitz
authors.affiliation: Heidelberg Ion-Beam Therapy Centre, Heidelberg, Germany.
authors.forename: Julia
authors.initials: J
authors.lastname: Bauer
authors.affiliation: University Hospital of Heidelberg, Department of Radiation Oncology, Heidelberg, Germany.
authors.forename: Thomas
authors.initials: T
authors.lastname: Welzel
authors.affiliation: University Hospital of Heidelberg, Department of Radiation Oncology, Heidelberg, Germany.
authors.forename: Harald
authors.initials: H
authors.lastname: Rief
authors.affiliation: Heidelberg Ion-Beam Therapy Centre, Heidelberg, Germany; German Cancer Research Center (DKFZ), Department of Medical Physics in Radiation Oncology, Heidelberg, Germany.
authors.forename: Oliver
authors.initials: O
authors.lastname: Jäkel
authors.affiliation: Heidelberg Ion-Beam Therapy Centre, Heidelberg, Germany.
authors.forename: Thomas
authors.initials: T
authors.lastname: Haberer
authors.affiliation: Ludwig-Maximilians-University of Munich, Department of Medical Physics, Garching, Germany.
authors.forename: Kathrin
authors.initials: K
authors.lastname: Frey
authors.affiliation: University Hospital of Heidelberg, Department of Radiation Oncology, Heidelberg, Germany.
authors.forename: Jürgen
authors.initials: J
authors.lastname: Debus
authors.affiliation: University Hospital of Heidelberg, Department of Radiation Oncology, Heidelberg, Germany; Ludwig-Maximilians-University of Munich, Department of Medical Physics, Garching, Germany.
authors.forename: Katia
authors.initials: K
authors.lastname: Parodi
authors.affiliation: University Hospital Klinikum rechts der Isar, Department of Radiation Oncology, Munich, Germany.
authors.forename: Stephanie E
authors.initials: SE
authors.lastname: Combs
authors.affiliation: University Hospital of Heidelberg, Department of Radiation Oncology, Heidelberg, Germany.
authors.forename: Stefan
authors.initials: S
authors.lastname: Rieken
mesh_terms: D000328:Adult; D000368:Aged; D005260:Female; D005909:Glioblastoma / Q000000981:diagnostic imaging*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009010:Monte Carlo Method; D049268:Positron-Emission Tomography / Q000379:methods; D011874:Radiometry; D014057:Tomography, X-Ray Computed / Q000379:methods*
keywords: Glioblastoma; In vivo dosimetry; Ion therapy; Monte Carlo simulation; PET; Range verification