title: Comparison of visual and semiquantitative analysis of 18F-FDOPA-PET/CT for recurrence detection in glioblastoma patients.
abstract: BACKGROUND
  Amino acid transport imaging with 18F-FDOPA PET is increasingly used for detection of glioblastoma recurrence. However, a standardized image interpretation for 18F-FDOPA brain PET studies has not yet been established. This study compares visual and semiquantitative analysis parameters for detection of tumor recurrence and correlates them with progression-free survival (PFS).
  
  
  METHODS
  One-hundred ten patients (72 male:38 female) with suspected tumor recurrence who underwent 18F-FDOPA PET imaging were studied. PET scans were analyzed visually (5-point scale) and semiquantitatively (lesion-to-striatum- and lesion- to-normal-brain-tissue ratios using both SUV(mean) and SUV(max)). Accuracies for recurrence detection were calculated using histopathology and clinical follow-up for validation. Receiving operator characteristic and Kaplan-Meier survival analysis were performed to derive imaging-based prediction of PFS and overall survival (OS).
  
  
  RESULTS
  Accuracies for detection of glioblastoma recurrence were similar for visual (82%) and semiquantitative (range, 77%-82%) analysis. Both visual and semiquantitative indices were significant predictors of PFS, with mean lesion-to normal brain tissue ratios providing the best discriminator (mean survival, 39.4 vs 9.3 months; P < .001). None of the investigated parameters was predictive for OS.
  
  
  CONCLUSIONS
  Both visual and semiquantitative indices detected glioblastoma recurrence with high accuracy and were predictive for PFS. Lesion-to-normal-tissue ratios were the best discriminators of PFS; however, none of the investigated parameters predicted OS. These retrospectively established analysis parameters need to be confirmed prospectively.
authors.affiliation: Ahmanson Translational Imaging Division, Department of Molecular and Medical Pharmacology, David Geffen School of Medicine at University of California Los Angeles, Los Angeles,California (K.H., J.C., K.P., M.R.B., M.E.P., W.C.); Department of Neurology, David Geffen School of Medicine at University of California Los Angeles,Los Angeles,California (T.C., A.L.); Department of Nuclear Medicine, Universitätsklinikum Würzburg, Würzburg, Germany (K.H., A.K.B.).
authors.forename: Ken
authors.initials: K
authors.lastname: Herrmann
authors.forename: Johannes
authors.initials: J
authors.lastname: Czernin
authors.forename: Timothy
authors.initials: T
authors.lastname: Cloughesy
authors.forename: Albert
authors.initials: A
authors.lastname: Lai
authors.forename: Kelsey L
authors.initials: KL
authors.lastname: Pomykala
authors.forename: Matthias R
authors.initials: MR
authors.lastname: Benz
authors.forename: Andreas K
authors.initials: AK
authors.lastname: Buck
authors.forename: Michael E
authors.initials: ME
authors.lastname: Phelps
authors.forename: Wei
authors.initials: W
authors.lastname: Chen
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D004295:Dihydroxyphenylalanine / Q000031:analogs & derivatives*; D005260:Female; D019788:Fluorodeoxyglucose F18; D005500:Follow-Up Studies; D005909:Glioblastoma / Q000000981:diagnostic imaging* / Q000401:mortality; D006801:Humans; D008297:Male; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local / Q000000981:diagnostic imaging* / Q000401:mortality; D049268:Positron-Emission Tomography / Q000379:methods*; D011379:Prognosis; D019275:Radiopharmaceuticals; D015996:Survival Rate; D014057:Tomography, X-Ray Computed / Q000379:methods*; D055815:Young Adult
chemical_list: D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18; C043437:fluorodopa F 18; D004295:Dihydroxyphenylalanine
keywords: 18F-FDOPA; glioblastoma; recurrence detection