title: O-(2-18F-fluoroethyl)-L-tyrosine PET predicts failure of antiangiogenic treatment in patients with recurrent high-grade glioma.
abstract: The objective of this study was to compare MRI response assessment with metabolic O-(2-(18)F-fluoroethyl)-L-tyrosine ((18)F-FET) PET response evaluation during antiangiogenic treatment in patients with recurrent high-grade glioma (rHGG).
  
  
  METHODS
  Eleven patients with rHGG were treated biweekly with bevacizumab-irinotecan. MR images and (18)F-FET PET scans were obtained at baseline and at follow-up 8-12 wk after treatment onset. MRI treatment response was evaluated by T1/T2 volumetry according to response assessment in neurooncology (RANO) criteria. For (18)F-FET PET evaluation, an uptake reduction of more than 45% calculated with a standardized uptake value of more than 1.6 was defined as a metabolic response (receiver-operating-characteristic curve analysis). MRI and (18)F-FET PET volumetry results and response assessment were compared with each other and in relation to progression-free survival (PFS) and overall survival (OS).
  
  
  RESULTS
  At follow-up, MR images showed partial response in 7 of 11 patients (64%), stable disease in 2 of 11 patients (18%), and tumor progression in 2 of 11 patients (18%). In contrast, (18)F-FET PET revealed 5 of 11 metabolic responders (46%) and 6 of 11 nonresponders (54%). MRI and (18)F-FET PET showed that responders survived significantly longer than did nonresponders (10.24 vs. 4.1 mo, P = 0.025, and 7.9 vs. 2.3 mo, P = 0.015, respectively). In 4 patients (36.4%), diagnosis according to RANO criteria and (18)F-FET PET was discordant. In these cases, PET was able to detect tumor progression earlier than was MRI.
  
  
  CONCLUSIONS
  In rHGG patients undergoing antiangiogenic treatment, (18)F-FET PET seems to be predictive for treatment failure in that it contributes important information to response assessment based solely on MRI and RANO criteria.
authors.affiliation: Department of Neurology, Innsbruck Medical University, Innsbruck, Austria. M.Hutterer@salk.at
authors.forename: Markus
authors.initials: M
authors.lastname: Hutterer
authors.forename: Martha
authors.initials: M
authors.lastname: Nowosielski
authors.forename: Daniel
authors.initials: D
authors.lastname: Putzer
authors.forename: Dietmar
authors.initials: D
authors.lastname: Waitz
authors.forename: Gerd
authors.initials: G
authors.lastname: Tinkhauser
authors.forename: Herwig
authors.initials: H
authors.lastname: Kostron
authors.forename: Armin
authors.initials: A
authors.lastname: Muigg
authors.forename: Irene J
authors.initials: IJ
authors.lastname: Virgolini
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Staffen
authors.forename: Eugen
authors.initials: E
authors.lastname: Trinka
authors.forename: Thaddäus
authors.initials: T
authors.lastname: Gotwald
authors.forename: Andreas H
authors.initials: AH
authors.lastname: Jacobs
authors.forename: Guenther
authors.initials: G
authors.lastname: Stockhammer
mesh_terms: D000328:Adult; D020533:Angiogenesis Inhibitors / Q000627:therapeutic use*; D000911:Antibodies, Monoclonal / Q000627:therapeutic use; D061067:Antibodies, Monoclonal, Humanized; D001254:Astrocytoma / Q000188:drug therapy / Q000473:pathology / Q000601:surgery; D000068258:Bevacizumab; D001932:Brain Neoplasms / Q000000981:diagnostic imaging* / Q000188:drug therapy*; D002166:Camptothecin / Q000031:analogs & derivatives / Q000627:therapeutic use; D003131:Combined Modality Therapy; D018572:Disease-Free Survival; D005260:Female; D005910:Glioma / Q000000981:diagnostic imaging* / Q000188:drug therapy* / Q000601:surgery; D006801:Humans; D007091:Image Processing, Computer-Assisted; D000077146:Irinotecan; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009422:Nervous System Diseases / Q000209:etiology / Q000503:physiopathology; D049268:Positron-Emission Tomography; D011183:Postoperative Complications / Q000503:physiopathology; D011237:Predictive Value of Tests; D019275:Radiopharmaceuticals; D012189:Retrospective Studies; D016019:Survival Analysis; D017211:Treatment Failure; D014443:Tyrosine / Q000031:analogs & derivatives*; D014463:Ultrasonography
chemical_list: D020533:Angiogenesis Inhibitors; D000911:Antibodies, Monoclonal; D061067:Antibodies, Monoclonal, Humanized; C117289:O-(2-fluoroethyl)tyrosine; D019275:Radiopharmaceuticals; D000068258:Bevacizumab; D014443:Tyrosine; D000077146:Irinotecan; D002166:Camptothecin