title: Consistency of metabolic tumor volume of non-small-cell lung cancer primary tumor measured using 18F-FDG PET/CT at two different tracer uptake times.
abstract: OBJECTIVE
  The objective of this study was to test the hypothesis that the metabolic tumor volume (MTV) of primary non-small-cell lung cancer is not sensitive to differences in F-fluorodeoxyglucose (F-FDG) uptake time, and to compare this consistency of MTV measurements with that of standardized uptake value (SUV) and total lesion glycolysis (TLG).
  
  
  METHODS
  Under Institutional Review Board approval, 134 consecutive patients with histologically proven non-small-cell lung cancer underwent F-FDG PET/computed tomography scanning at about 1 h (early) and 2 h (delayed) after intravenous injection of F-FDG. MTV, SUV, and TLG of the primary tumor were all measured. Student's t-test and Wilcoxon's signed-rank test for paired data were used to compare MTV, SUV, and TLG between the two scans. The intraclass correlation coefficient (ICC) was used to assess agreement in PET parameters between the two scans and between the measurements made by two observers.
  
  
  RESULTS
  MTV was not significantly different (P=0.17) between the two scans. However, SUVmax, SUVmean, SUVpeak, and TLG increased significantly from the early to the delayed scans (P<0.0001 for all). The median percentage change between the two scans in MTV (1.65%) was smaller than in SUVmax (11.76%), SUVmean(10.57%), SUVpeak(13.51%), and TLG (14.34%); the ICC of MTV (0.996) was greater than that of SUVmax (0.933), SUVmean (0.952), SUVpeak (0.928), and TLG (0.982). Interobserver agreement between the two radiologists was excellent for MTV, SUV, and TLG on both scans (ICC: 0.934-0.999).
  
  
  CONCLUSIONS
  MTV is not sensitive to common clinical variations in F-FDG uptake time, its consistency is greater than that of SUVmax, SUVmean, SUVpeak, and TLG, and it has excellent interobserver agreement.
authors.affiliation: aPET/CT Center, The First Affiliated Hospital of Guangzhou Medical University, Guangzhou, Guangdong bDepartment of Nuclear Medicine, Ren Ji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China Departments of cPublic Health Sciences dRadiology, University of Chicago, Chicago, Illinois, USA.
authors.forename: Haiping
authors.initials: H
authors.lastname: Liu
authors.forename: Ping
authors.initials: P
authors.lastname: Chen
authors.forename: Kristen
authors.initials: K
authors.lastname: Wroblewski
authors.forename: Peng
authors.initials: P
authors.lastname: Hou
authors.forename: Chen-Peng
authors.initials: CP
authors.lastname: Zhang
authors.forename: Yulei
authors.initials: Y
authors.lastname: Jiang
authors.forename: Yonglin
authors.initials: Y
authors.lastname: Pu
mesh_terms: D000368:Aged; D001692:Biological Transport; D002289:Carcinoma, Non-Small-Cell Lung / Q000175:diagnosis* / Q000378:metabolism / Q000473:pathology; D005260:Female; D019788:Fluorodeoxyglucose F18 / Q000378:metabolism; D006019:Glycolysis; D006801:Humans; D007700:Kinetics; D008175:Lung Neoplasms / Q000175:diagnosis* / Q000378:metabolism / Q000473:pathology; D008297:Male; D008875:Middle Aged; D064847:Multimodal Imaging; D015588:Observer Variation; D049268:Positron-Emission Tomography; D011379:Prognosis; D014057:Tomography, X-Ray Computed; D047368:Tumor Burden
chemical_list: D019788:Fluorodeoxyglucose F18