title: Reproducibility and uptake time dependency of volume-based parameters on FDG-PET for lung cancer.
abstract: Volume-based parameters, such as metabolic tumor volume (MTV) and total lesion glycolysis (TLG), on F-18 fluorodeoxyglucose (FDG) positron emission tomography (PET) are useful for predicting treatment response in nonsmall cell lung cancer (NSCLC). We aimed to examine intra- and inter-operator reproducibility to measure the MTV and TLG, and to estimate their dependency on the uptake time.
  
  
  
  Fifty NSCLC patients underwent preoperative FDG-PET. After an injection of FDG, the whole body was scanned twice: at the early phase (61.4 ± 2.8 min) and delayed phase (117.7 ± 1.6 min). Two operators independently defined the tumor boundary using three different delineation methods: (1) the absolute SUV threshold method (MTVp and TLGp; p = 2.0, 2.5, 3.0, 3.5), (2) the fixed% SUVmax threshold method (MTVq% and TLGq%; q = 35, 40, 45), and (3) the adaptive region-growing method (MTVARG and TLGARG). Parameters were compared between operators and between phases.
  
  
  
  Both the intra- and inter-operator reproducibility were high for all parameters using any method (intra-class correlation > 0.99 each). MTV3.0 and MTV3.5 resulted in a significant increase from the early to delayed phase (P < 0.05 for both), whereas MTV2.0 and MTV2.5 neither increased nor decreased (P = n.s.). All of the MTVq% values significantly decreased over time (P < 0.01), whereas MTVARG and TLG with any delineation method increased significantly (P < 0.05).
  
  
  
  High reproducibility of MTV and TLG was obtained by all of the methods used. MTV2.0 and MTV2.5 were the least sensitive to uptake time, and may be good alternatives when we compare images acquired with different uptake times, although applying constant uptake time is important for volume measurement.
authors.affiliation: Radiology Department, National Hospital Organization, Hokkaido Cancer Center, 2-3-54, Kikusui-4, Shiroishi-Ku, Sapporo, 003-0804, Japan.|Department of Nuclear Medicine, Graduate School of Medicine, Hokkaido University, Kita 15, Nishi 7, Kita-Ku, Sapporo, Hokkaido, 060-8638, Japan.
authors.forename: Tomoka
authors.initials: T
authors.lastname: Kitao
authors.affiliation: Department of Nuclear Medicine, Graduate School of Medicine, Hokkaido University, Kita 15, Nishi 7, Kita-Ku, Sapporo, Hokkaido, 060-8638, Japan. khirata@med.hokudai.ac.jp.
authors.forename: Kenji
authors.initials: K
authors.lastname: Hirata
authors.affiliation: Radiology Department, National Hospital Organization, Hokkaido Cancer Center, 2-3-54, Kikusui-4, Shiroishi-Ku, Sapporo, 003-0804, Japan.
authors.forename: Katsumi
authors.initials: K
authors.lastname: Shima
authors.affiliation: Radiology Department, National Hospital Organization, Hokkaido Cancer Center, 2-3-54, Kikusui-4, Shiroishi-Ku, Sapporo, 003-0804, Japan.
authors.forename: Takashi
authors.initials: T
authors.lastname: Hayashi
authors.affiliation: Radiology Department, National Hospital Organization, Hokkaido Cancer Center, 2-3-54, Kikusui-4, Shiroishi-Ku, Sapporo, 003-0804, Japan.
authors.forename: Mitsunori
authors.initials: M
authors.lastname: Sekizawa
authors.affiliation: Department of Diagnostic Radiology, Hokkaido Cancer Center, Sapporo, Japan.
authors.forename: Toshiki
authors.initials: T
authors.lastname: Takei
authors.affiliation: Department of Diagnostic Radiology, Hokkaido Cancer Center, Sapporo, Japan.
authors.forename: Wataru
authors.initials: W
authors.lastname: Ichimura
authors.affiliation: Department of Respiratory Medicine, Hokkaido Cancer Center, Sapporo, Japan.
authors.forename: Masao
authors.initials: M
authors.lastname: Harada
authors.affiliation: Department of Thoracic Surgery, Hokkaido Cancer Center, Sapporo, Japan.
authors.forename: Keishi
authors.initials: K
authors.lastname: Kondo
authors.affiliation: Department of Nuclear Medicine, Graduate School of Medicine, Hokkaido University, Kita 15, Nishi 7, Kita-Ku, Sapporo, Hokkaido, 060-8638, Japan.
authors.forename: Nagara
authors.initials: N
authors.lastname: Tamaki
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D002289:Carcinoma, Non-Small-Cell Lung / Q000000981:diagnostic imaging*; D005260:Female; D019788:Fluorodeoxyglucose F18 / Q000378:metabolism*; D006019:Glycolysis; D006801:Humans; D008175:Lung Neoplasms / Q000000981:diagnostic imaging*; D008297:Male; D008875:Middle Aged; D015588:Observer Variation; D049268:Positron-Emission Tomography / Q000379:methods*; D011379:Prognosis; D019275:Radiopharmaceuticals / Q000378:metabolism*; D015203:Reproducibility of Results; D012189:Retrospective Studies; D047368:Tumor Burden
chemical_list: D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18
keywords: FDG-PET; Lung cancer; Metabolic tumor volume; Reproducibility; Total lesion glycolysis