title: Visual versus quantitative assessment of intratumor 18F-FDG PET uptake heterogeneity: prognostic value in non-small cell lung cancer.
abstract: The goal of this study was to compare visual assessment of intratumor (18)F-FDG PET uptake distribution with a textural-features (TF) automated quantification and to establish their respective prognostic value in non-small cell lung cancer (NSCLC).
  
  
  METHODS
  The study retrospectively included 102 consecutive patients. Only primary tumors were considered. Intratumor heterogeneity was visually scored (3-level scale [Hvisu]) by 2 nuclear medicine physicians. Tumor volumes were automatically delineated, and heterogeneity was quantified with TF. Mean and maximum standardized uptake value were also included. Visual interobserver agreement and correlations with quantitative assessment were evaluated using the κ test and Spearman rank (ρ) coefficient, respectively. Association with overall survival and recurrence-free survival was investigated using the Kaplan-Meier method and Cox regression models.
  
  
  RESULTS
  Moderate correlations (0.4 < ρ < 0.6) between TF parameters and Hvisu were observed. Interobserver agreement for Hvisu was moderate (κ = 0.64, discrepancies in 27% of the cases). High standardized uptake value, large metabolic volumes, and high heterogeneity according to TF were associated with poorer overall survival and recurrence-free survival and remained an independent prognostic factor of overall survival with respect to clinical variables.
  
  
  CONCLUSIONS
  Quantification of (18)F-FDG uptake heterogeneity in NSCLC through TF was correlated with visual assessment by experts. However, TF also constitutes an objective heterogeneity quantification, with reduced interobserver variability, and independent prognostic value potentially useful for patient stratification and management.
authors.affiliation: Nuclear Medicine, CHU Milétrie, Poitiers, France INSERM, UMR 1101, LaTIM, Brest, France.
authors.forename: Florent
authors.initials: F
authors.lastname: Tixier
authors.affiliation: INSERM, UMR 1101, LaTIM, Brest, France hatt@univ-brest.fr.
authors.forename: Mathieu
authors.initials: M
authors.lastname: Hatt
authors.affiliation: Nuclear Medicine, CHU Milétrie, Poitiers, France.
authors.forename: Clemence
authors.initials: C
authors.lastname: Valla
authors.affiliation: Nuclear Medicine, CHU Milétrie, Poitiers, France.
authors.forename: Vincent
authors.initials: V
authors.lastname: Fleury
authors.affiliation: Department of Oncology, CHU Milétrie, Poitiers, France; and.
authors.forename: Corinne
authors.initials: C
authors.lastname: Lamour
authors.affiliation: Nuclear Medicine, CHU Milétrie, Poitiers, France.
authors.forename: Safaa
authors.initials: S
authors.lastname: Ezzouhri
authors.affiliation: Epidemiology and Biostatistics, CIC Inserm 1402, CHU Milétrie, Poitiers, France.
authors.forename: Pierre
authors.initials: P
authors.lastname: Ingrand
authors.affiliation: Nuclear Medicine, CHU Milétrie, Poitiers, France.
authors.forename: Remy
authors.initials: R
authors.lastname: Perdrisot
authors.affiliation: INSERM, UMR 1101, LaTIM, Brest, France.
authors.forename: Dimitris
authors.initials: D
authors.lastname: Visvikis
authors.affiliation: Nuclear Medicine, CHU Milétrie, Poitiers, France.
authors.forename: Catherine Cheze
authors.initials: CC
authors.lastname: Le Rest
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001692:Biological Transport; D002289:Carcinoma, Non-Small-Cell Lung / Q000000981:diagnostic imaging* / Q000378:metabolism / Q000473:pathology; D005260:Female; D019788:Fluorodeoxyglucose F18 / Q000378:metabolism*; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods*; D008175:Lung Neoplasms / Q000000981:diagnostic imaging* / Q000378:metabolism / Q000473:pathology; D008297:Male; D008875:Middle Aged; D015588:Observer Variation; D049268:Positron-Emission Tomography; D011379:Prognosis; D012189:Retrospective Studies; D016019:Survival Analysis
chemical_list: D019788:Fluorodeoxyglucose F18
keywords: 18FDG-PET/CT; NSCLC; heterogeneity; prognosis; textural features