title: Pretreatment F-18 FDG PET/CT Parameters to Evaluate Progression-Free Survival in Gastric Cancer.
abstract: OBJECTIVE
  We performed this study to evaluate the predictive value of pretreatment F-18 FDG PET/CT for progression-free survival (PFS) in patients with gastric cancer.
  
  
  METHODS
  Of 321 patients with a diagnosis of gastric cancer, we retrospectively enrolled 97 patients (men:women = 61:36, age 59.8 ± 13.2 years), who underwent pretreatment F-18 fluoro-2-deoxyglucose positron emission tomography/computed tomography (F-18 FDG PET/CT) from January 2009 to December 2009. Maximum standardized uptake value (SUVmax) was measured for each case with detectable primary lesions. In the remaining non-detectable cases, SUVmax was measured from the corresponding site seen on gastroduodenoscopy for analysis. In subgroup analysis, metabolic tumor volume (MTV) was measured in 50 patients with clearly distinguishable primary lesions. SUVmax, stage, depth of tumor invasion and presence of lymph node metastasis were analyzed in terms of PFS. Receiver operating characteristic (ROC) curves were used to find optimal cutoff values of SUVmax and MTV for disease progression. The relationship between SUVmax, MTV and PFS was analyzed using the Kaplan-Meier with log-rank test and Cox's proportional hazard regression methods.
  
  
  RESULTS
  Of 97 patients, 15 (15.5 %) had disease progression. The mean follow-up duration was 29.6 ± 10.2 months. The mean PFS of low SUVmax group (≤5.74) was significantly longer than that of the high SUVmax group (>5.74) (30.9 ± 8.0 vs 24.3 ± 13.6 months, p = 0.008). In univariate analysis, stage (I vs II, III, IV), depth of tumor invasion (T1 vs T2, T3, T4), presence of lymph node metastasis and SUVmax (>5.74 vs ≤5.74) were significantly associated with recurrence. In multivariate analysis, high SUVmax (>5.74) was the only poor prognostic factor for PFS (p = 0.002, HR 11.03, 95 % CI 2.48-49.05). Subgroup multivariate analysis revealed that high MTV (>16.42) was the only poor prognostic factor for PFS (p = 0.034, HR 3.59, 95 % CI 1.10-11.71).
  
  
  CONCLUSIONS
  In gastric cancer, SUVmax measured by pretreatment F-18 FDG PET/CT has a significant predictive value for PFS. In addition, if MTV is measurable, high MTV is an independent factor for disease progression.
authors.affiliation: Department of Nuclear Medicine, Chonbuk National University Medical School and Hospital, Jeonju, Republic of Korea.
authors.forename: Jeonghun
authors.initials: J
authors.lastname: Kim
authors.affiliation: Department of Nuclear Medicine, Chonbuk National University Medical School and Hospital, Jeonju, Republic of Korea ; Department of Nuclear Medicine, Research Institute of Clinical Medicine, Cyclotron Research Center, Molecular Imaging & Therapeutic Medicine Research Center, Chonbuk National University Medical School and Hospital, Jeonju, Republic of Korea.
authors.forename: Seok Tae
authors.initials: ST
authors.lastname: Lim
authors.affiliation: Department of Nuclear Medicine, Chonbuk National University Medical School and Hospital, Jeonju, Republic of Korea.
authors.forename: Chang Ju
authors.initials: CJ
authors.lastname: Na
authors.affiliation: Department of Nuclear Medicine, Chonbuk National University Medical School and Hospital, Jeonju, Republic of Korea.
authors.forename: Yeon-Hee
authors.initials: YH
authors.lastname: Han
authors.affiliation: Department of Surgery, Research Institute of Clinical Medicine, Chonbuk National University Medical School and Hospital, Jeonju, Republic of Korea.
authors.forename: Chan-Young
authors.initials: CY
authors.lastname: Kim
authors.affiliation: Department of Nuclear Medicine, Chonbuk National University Medical School and Hospital, Jeonju, Republic of Korea ; Department of Nuclear Medicine, Research Institute of Clinical Medicine, Cyclotron Research Center, Molecular Imaging & Therapeutic Medicine Research Center, Chonbuk National University Medical School and Hospital, Jeonju, Republic of Korea.
authors.forename: Hwan-Jeong
authors.initials: HJ
authors.lastname: Jeong
authors.affiliation: Department of Nuclear Medicine, Chonbuk National University Medical School and Hospital, Jeonju, Republic of Korea ; Department of Nuclear Medicine, Research Institute of Clinical Medicine, Cyclotron Research Center, Molecular Imaging & Therapeutic Medicine Research Center, Chonbuk National University Medical School and Hospital, Jeonju, Republic of Korea.
authors.forename: Myung-Hee
authors.initials: MH
authors.lastname: Sohn
keywords: F-18 FDG PET/CT; Gastric cancer; Maximum standardized uptake value; Metabolic tumor volume; Prognosis; Progression-free survival