title: Early and late effects of radiochemotherapy on cerebral blood flow in glioblastoma patients measured with non-invasive perfusion MRI.
abstract: OBJECTIVE
  To provide a systematic measure of changes of brain perfusion in healthy tissue following a fractionated radiotherapy of brain tumors.
  
  
  METHODS
  Perfusion was assessed before and after radiochemotherapy using arterial spin labeling in a group of 24 patients (mean age 54.3 ± 14.1 years) with glioblastoma multiforme. Mean relative perfusion change in gray matter in the hemisphere contralateral to the tumor was obtained for the whole hemisphere and also for six regions created by thresholding the individual dose maps at 10 Gy steps.
  
  
  RESULTS
  A significant decrease of perfusion of -9.8 ± 20.9% (p=0.032) compared to the pre-treatment baseline was observed 3 months after the end of radiotherapy. The decrease was more pronounced for high-dose regions above 50 Gy (-16.8 ± 21.0%, p=0.0014) than for low-dose regions below 10 Gy (-2.3 ± 20.0%, p=0.54). No further significant decrease compared to the post-treatment baseline was observed 6 months (-0.4 ± 18.4%, p=0.94) and 9 months (2.0 ± 15.4%, p=0.74) after the end of radiotherapy.
  
  
  CONCLUSIONS
  Perfusion decreased significantly during the course of radiochemotherapy. The decrease was higher in regions receiving a higher dose of radiation. This suggests that the perfusion decrease is at least partly caused by radiotherapy. Our results suggest that the detrimental effects of radiochemotherapy on perfusion occur early rather than later.
authors.affiliation: Helmholtz-Zentrum Dresden-Rossendorf, PET Center, Institute of Radiopharmaceutical Cancer Research, Dresden, Germany. Electronic address: j.petr@hzdr.de.
authors.forename: Jan
authors.initials: J
authors.lastname: Petr
authors.affiliation: Department of Radiology, University Hospital Carl Gustav Carus, Technical University Dresden, Germany.
authors.forename: Ivan
authors.initials: I
authors.lastname: Platzek
authors.affiliation: Department of Radiation Oncology, Faculty of Medicine and University Hospital Carl Gustav Carus, Technical University Dresden, Germany; OncoRay - National Center for Radiation Research in Oncology, Faculty of Medicine and University Hospital Carl Gustav Carus, Technical University Dresden, Germany; German Cancer Consortium (DKTK) Dresden and German Cancer Research Center (DKFZ) Heidelberg, Germany.
authors.forename: Annekatrin
authors.initials: A
authors.lastname: Seidlitz
authors.affiliation: Brain Sciences Research Program, Sunnybrook Research Institute, Toronto, Canada.
authors.forename: Henri J M M
authors.initials: HJ
authors.lastname: Mutsaerts
authors.affiliation: Helmholtz-Zentrum Dresden-Rossendorf, PET Center, Institute of Radiopharmaceutical Cancer Research, Dresden, Germany.
authors.forename: Frank
authors.initials: F
authors.lastname: Hofheinz
authors.affiliation: Helmholtz-Zentrum Dresden-Rossendorf, PET Center, Institute of Radiopharmaceutical Cancer Research, Dresden, Germany; Department of Imaging and Pathology, Katholieke Universiteit Leuven, Belgium.
authors.forename: Georg
authors.initials: G
authors.lastname: Schramm
authors.affiliation: Helmholtz-Zentrum Dresden-Rossendorf, PET Center, Institute of Radiopharmaceutical Cancer Research, Dresden, Germany.
authors.forename: Jens
authors.initials: J
authors.lastname: Maus
authors.affiliation: Helmholtz-Zentrum Dresden-Rossendorf, PET Center, Institute of Radiopharmaceutical Cancer Research, Dresden, Germany; Department of Nuclear Medicine, University Hospital Carl Gustav Carus, Technical University Dresden, Germany.
authors.forename: Bettina
authors.initials: B
authors.lastname: Beuthien-Baumann
authors.affiliation: Department of Radiation Oncology, Faculty of Medicine and University Hospital Carl Gustav Carus, Technical University Dresden, Germany; OncoRay - National Center for Radiation Research in Oncology, Faculty of Medicine and University Hospital Carl Gustav Carus, Technical University Dresden, Germany; German Cancer Consortium (DKTK) Dresden and German Cancer Research Center (DKFZ) Heidelberg, Germany; Helmholtz-Zentrum Dresden-Rossendorf, Institute of Radiooncology, Germany.
authors.forename: Mechthild
authors.initials: M
authors.lastname: Krause
authors.affiliation: Helmholtz-Zentrum Dresden-Rossendorf, PET Center, Institute of Radiopharmaceutical Cancer Research, Dresden, Germany; Department of Nuclear Medicine, University Hospital Carl Gustav Carus, Technical University Dresden, Germany.
authors.forename: Jörg
authors.initials: J
authors.lastname: van den Hoff
mesh_terms: D000328:Adult; D000368:Aged; D001921:Brain / Q000098:blood supply / Q000503:physiopathology; D001932:Brain Neoplasms / Q000503:physiopathology / Q000628:therapy*; D002560:Cerebrovascular Circulation / Q000502:physiology*; D059248:Chemoradiotherapy; D005260:Female; D005909:Glioblastoma / Q000503:physiopathology / Q000628:therapy*; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D013113:Spin Labels; D016896:Treatment Outcome
chemical_list: D013113:Spin Labels
keywords: ASL; Arterial spin labeling; Brain tumor; Cerebral blood flow; Perfusion; Radiotherapy