title: Response assessment of bevacizumab therapy in GBM with integrated 11C-MET-PET/MRI: a feasibility study.
abstract: BACKGROUND
  The objective of this study was to evaluate the potential of integrated 11C-MET PET/MR for response assessment of relapsed glioblastoma (GBM) receiving bevacizumab treatment.
  
  
  METHODS
  Eleven consecutive patients with relapsed GBM were enrolled for an integrated 11C-MET PET/MRI at baseline and at follow-up. Treatment response for MRI was evaluated according to Response Assessment in Neuro-oncology (RANO) criteria and integrated 11C-MET PET was assessed by the T/N ratio.
  
  
  RESULTS
  MRI showed no patient with complete response (CR), six of 11 patients with PR, four of 11 patients with SD, and one of 11 patients with progressive disease (PD). PET revealed metabolic response in five of the six patients with partial response (PR) and in two of the four patients with stable disease (SD), whereas metabolic non-response was detected in one of the six patients with PR, in two of the four patients with SD, and in the one patient with PD. Morphological imaging was predictive for PFS and OS when response was defined as CR, PR, SD, and non-response as PD. Metabolic imaging was predictive when using T/N ratio reduction of >25 as discriminator. Based on the morphologic and metabolic findings of this study a proposal for applying integrated PET/MRI for treatment response in relapsed GBM was developed, which was significantly predictive for PFS and OS (P = 0.010 respectively 0,029, log).
  
  
  CONCLUSIONS
  This study demonstrates the potential of integrated 11C-MET-PET/MRI for response assessment of GBM and the utility of combined assessment of morphologic and metabolic information with the proposal for assessing relapsed GBM.
authors.affiliation: Institute of Diagnostic and Interventional Radiology and Neuroradiology, University Hospital Essen, Hufelandstrasse 55, D-45122, Essen, Germany. cornelius.deuschl@uk-essen.de.|Erwin L. Hahn Institute for Magnetic Resonance Imaging, University of Duisburg-Essen, Duisburg, Germany. cornelius.deuschl@uk-essen.de.
authors.forename: Cornelius
authors.initials: C
authors.lastname: Deuschl
authors.affiliation: Institute of Diagnostic and Interventional Radiology and Neuroradiology, University Hospital Essen, Hufelandstrasse 55, D-45122, Essen, Germany.
authors.forename: Christoph
authors.initials: C
authors.lastname: Moenninghoff
authors.affiliation: Institute of Diagnostic and Interventional Radiology and Neuroradiology, University Hospital Essen, Hufelandstrasse 55, D-45122, Essen, Germany.
authors.forename: Sophia
authors.initials: S
authors.lastname: Goericke
authors.affiliation: Institute of Diagnostic and Interventional Radiology, University Hospital Duesseldorf, Duesseldorf, Germany.
authors.forename: Julian
authors.initials: J
authors.lastname: Kirchner
authors.affiliation: Department of Neurology, University Hospital Essen, Essen, Germany.
authors.forename: Susanne
authors.initials: S
authors.lastname: Köppen
authors.affiliation: Department of Nuclear Medicine, University Hospital Essen, Essen, Germany.
authors.forename: Ina
authors.initials: I
authors.lastname: Binse
authors.affiliation: Department of Nuclear Medicine, University Hospital Essen, Essen, Germany.
authors.forename: Thorsten D
authors.initials: TD
authors.lastname: Poeppel
authors.affiliation: Erwin L. Hahn Institute for Magnetic Resonance Imaging, University of Duisburg-Essen, Duisburg, Germany.|High Field and Hybrid MR Imaging, University Hospital Essen, Essen, Germany.
authors.forename: Harald H
authors.initials: HH
authors.lastname: Quick
authors.affiliation: Institute of Diagnostic and Interventional Radiology and Neuroradiology, University Hospital Essen, Hufelandstrasse 55, D-45122, Essen, Germany.
authors.forename: Michael
authors.initials: M
authors.lastname: Forsting
authors.affiliation: Institute of Diagnostic and Interventional Radiology and Neuroradiology, University Hospital Essen, Hufelandstrasse 55, D-45122, Essen, Germany.
authors.forename: Lale
authors.initials: L
authors.lastname: Umutlu
authors.affiliation: Department of Nuclear Medicine, University Hospital Essen, Essen, Germany.
authors.forename: Ken
authors.initials: K
authors.lastname: Herrmann
authors.affiliation: Department of Medical Oncology, West German Cancer Center, University Hospital Essen, Essen, Germany.
authors.forename: Joerg
authors.initials: J
authors.lastname: Hense
authors.affiliation: Institute of Diagnostic and Interventional Radiology and Neuroradiology, University Hospital Essen, Hufelandstrasse 55, D-45122, Essen, Germany.|Department of Neuroradiology, University Hospital Giessen, Essen, Germany.
authors.forename: Marc
authors.initials: M
authors.lastname: Schlamann
mesh_terms: D000328:Adult; D000068258:Bevacizumab / Q000627:therapeutic use*; D001932:Brain Neoplasms / Q000000981:diagnostic imaging / Q000188:drug therapy*; D018572:Disease-Free Survival; D005240:Feasibility Studies; D005260:Female; D005909:Glioblastoma / Q000000981:diagnostic imaging / Q000188:drug therapy*; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008715:Methionine / Q000031:analogs & derivatives*; D008875:Middle Aged; D064847:Multimodal Imaging; D049268:Positron-Emission Tomography; D016896:Treatment Outcome
chemical_list: D000068258:Bevacizumab; D008715:Methionine; C038344:methionine methyl ester
keywords: 11C-MET-PET; GBM; Integrated PET/MRI; Response assessment