title: The increment in standardized uptake value determined using dual-phase 18F-FDG PET is a promising prognostic factor in non-small-cell lung cancer.
abstract: OBJECTIVE
  We aimed to determine whether the increment in the maximal standardized uptake value (SUVmax) of the primary lung tumour between the initial and delayed imaging by dual-phase (18)F-FDG PET has prognostic value in patients with non-small-cell lung cancer (NSCLC).
  
  
  METHODS
  We reviewed the records of patients with NSCLC who underwent pretreatment dual-phase (18)F-FDG PET/CT scans acquired at 1 h and 2 h after injection. The SUVmax increment (SUVinc) of the primary lung tumour was the 2-h SUVmax minus the 1-h SUVmax. Univariate and multivariate analyses were used to assess the prognostic significance of SUVinc, retention index, whole-body total metabolic tumour volume, whole-body total lesion glycolysis (TLGwb), 1-h SUVmax, 2-h SUVmax, gender, age, performance status, histological subtype, T stage, N stage and clinical stage.
  
  
  RESULTS
  The records of 187 consecutive patients were reviewed. The median follow-up time was 3.9 years. The estimated median progression-free survival (PFS) and overall survival (OS) were 1.3 years and 4.4 years, respectively. An SUVinc cut-off value of >1 had the best discriminative yield for PFS. The 3-year PFS and OS were 61.6 % and 87.8 % in patients with SUVinc ≤ 1 versus 21.1 % and 46.2 % in patients with SUVinc >1 (all P < 0.01). Using the forward stepwise multivariate Cox proportional hazards model, SUVinc, TLGwb, and clinical stage were significant factors for PFS (all P < 0.01). A subgroup analysis of 117 patients treated with surgery showed that SUVinc (P = 0.02) and clinical stage (P < 0.01) were significant prognostic factors for PFS. Furthermore, in stage I patients treated with surgery alone, SUVinc was the only significant prognostic factor (HR 28.07; 95 % CI 2.42 - 326.41).
  
  
  CONCLUSIONS
  SUVinc determined from dual-phase (18)F-FDG PET is a promising prognostic factor for NSCLC. It adds to the value of dual-phase (18)F-FDG PET.
authors.affiliation: Department of Radiation Oncology, National Cheng Kung University Hospital, College of Medicine, National Cheng Kung University, 138 Sheng-Li Road, Tainan 704, Taiwan.
authors.forename: Helen H W
authors.initials: HH
authors.lastname: Chen
authors.forename: Bi-Fang
authors.initials: BF
authors.lastname: Lee
authors.forename: Wu-Chou
authors.initials: WC
authors.lastname: Su
authors.forename: Yu-Hsuan
authors.initials: YH
authors.lastname: Lai
authors.forename: Hung-Yu
authors.initials: HY
authors.lastname: Chen
authors.forename: How-Ran
authors.initials: HR
authors.lastname: Guo
authors.forename: Wei-Jen
authors.initials: WJ
authors.lastname: Yao
authors.forename: Nan-Tsing
authors.initials: NT
authors.lastname: Chiu
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002289:Carcinoma, Non-Small-Cell Lung / Q000000981:diagnostic imaging*; D003627:Data Interpretation, Statistical; D005260:Female; D019788:Fluorodeoxyglucose F18; D006801:Humans; D008175:Lung Neoplasms / Q000000981:diagnostic imaging*; D008297:Male; D008875:Middle Aged; D049268:Positron-Emission Tomography / Q000592:standards*; D011237:Predictive Value of Tests; D019275:Radiopharmaceuticals; D012015:Reference Standards
chemical_list: D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18