title: Kinetic Modeling and Graphical Analysis of 18F-Fluoromethylcholine (FCho), 18F-Fluoroethyltyrosine (FET) and 18F-Fluorodeoxyglucose (FDG) PET for the Fiscrimination between High-Grade Glioma and Radiation Necrosis in Rats.
abstract: BACKGROUND
  Discrimination between glioblastoma (GB) and radiation necrosis (RN) post-irradiation remains challenging but has a large impact on further treatment and prognosis. In this study, the uptake mechanisms of 18F-fluorodeoxyglucose (18F-FDG), 18F-fluoroethyltyrosine (18F-FET) and 18F-fluoromethylcholine (18F-FCho) positron emission tomography (PET) tracers were investigated in a F98 GB and RN rat model applying kinetic modeling (KM) and graphical analysis (GA) to clarify our previous results.
  
  
  METHODS
  Dynamic 18F-FDG (GB n = 6 and RN n = 5), 18F-FET (GB n = 5 and RN n = 5) and 18F-FCho PET (GB n = 5 and RN n = 5) were acquired with continuous arterial blood sampling. Arterial input function (AIF) corrections, KM and GA were performed.
  
  
  RESULTS
  The influx rate (Ki) of 18F-FDG uptake described by a 2-compartmental model (CM) or using Patlak GA, showed more trapping (k3) in GB (0.07 min-1) compared to RN (0.04 min-1) (p = 0.017). K1 of 18F-FET was significantly higher in GB (0.06 ml/ccm/min) compared to RN (0.02 ml/ccm/min), quantified using a 1-CM and Logan GA (p = 0.036). 18F-FCho was rapidly oxidized complicating data interpretation. Using a 1-CM and Logan GA no clear differences were found to discriminate GB from RN.
  
  
  CONCLUSIONS
  Based on our results we concluded that using KM and GA both 18F-FDG and 18F-FET were able to discriminate GB from RN. Using a 2-CM model more trapping of 18F-FDG was found in GB compared to RN. Secondly, the influx of 18F-FET was higher in GB compared to RN using a 1-CM model. Important correlations were found between SUV and kinetic or graphical measures for 18F-FDG and 18F-FET. 18F-FCho PET did not allow discrimination between GB and RN.
authors: Department of Nuclear Medicine, Ghent University Hospital, Ghent, Belgium.
authors: Julie
authors: http://orcid.org/0000-0001-8554-280X
authors: J
authors: Bolcaen
authors: Department of Nuclear Medicine, Ghent University Hospital, Ghent, Belgium.
authors: Kelly
authors: K
authors: Lybaert
authors: Department of Nuclear Medicine, Ghent University Hospital, Ghent, Belgium.
authors: Lieselotte
authors: L
authors: Moerman
authors: iMinds-IBiTech-MEDISIP, Department of Electronics and Information Systems, Ghent University, Ghent, Belgium.
authors: Benedicte
authors: B
authors: Descamps
authors: Department of Radiology, Ghent University Hospital, Ghent, Belgium.
authors: Karel
authors: K
authors: Deblaere
authors: Department of Radiation Oncology, Ghent University Hospital, Ghent, Belgium.
authors: Tom
authors: T
authors: Boterberg
authors: Department of Neurosurgery, Ghent University Hospital, Ghent, Belgium.
authors: Jean-Pierre
authors: JP
authors: Kalala
authors: Department of Pathology, Ghent University Hospital, Ghent, Belgium.
authors: Caroline
authors: C
authors: Van den Broecke
authors: Department of Radiopharmacy, Ghent University, Ghent, Belgium.
authors: Filip
authors: F
authors: De Vos
authors: iMinds-IBiTech-MEDISIP, Department of Electronics and Information Systems, Ghent University, Ghent, Belgium.
authors: Christian
authors: C
authors: Vanhove
authors: Department of Nuclear Medicine, Ghent University Hospital, Ghent, Belgium.
authors: Ingeborg
authors: I
authors: Goethals
mesh_terms: D000818:Animals; D001921:Brain / Q000000981:diagnostic imaging / Q000473:pathology; D045744:Cell Line, Tumor; D002794:Choline / Q000031:analogs & derivatives* / Q000493:pharmacokinetics; D003937:Diagnosis, Differential; D004195:Disease Models, Animal; D005260:Female; D019788:Fluorodeoxyglucose F18 / Q000493:pharmacokinetics*; D005909:Glioblastoma / Q000175:diagnosis / Q000000981:diagnostic imaging* / Q000378:metabolism; D006801:Humans; D007700:Kinetics; D009336:Necrosis / Q000175:diagnosis / Q000000981:diagnostic imaging / Q000378:metabolism; D060787:Neoplasm Grading; D049268:Positron-Emission Tomography / Q000379:methods*; D011832:Radiation Injuries / Q000175:diagnosis / Q000000981:diagnostic imaging* / Q000378:metabolism; D019275:Radiopharmaceuticals / Q000493:pharmacokinetics; D011916:Rats, Inbred F344; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D014443:Tyrosine / Q000031:analogs & derivatives* / Q000493:pharmacokinetics
chemical_list: D019275:Radiopharmaceuticals; C516370:fluoromethylcholine; D019788:Fluorodeoxyglucose F18; C545932:(18F)fluoroethyltyrosine; D014443:Tyrosine; D002794:Choline