title: Prognostic Value of Volume-Based Metabolic Parameters Measured by (18)F-FDG PET/CT of Pancreatic Neuroendocrine Tumors.
abstract: OBJECTIVE
  To date, the prognostic value of (18)F-FDG PET/CT for patients with pancreatic neuroendocrine tumors (PNETs) has not been well characterized. We investigated the prognostic value of volumetric parameters using (18)F-FDG PET/CT in this patient population.
  
  
  METHODS
  We retrospectively reviewed 20 cases of pathologically proven PNET in patients who had undergone pre-therapeutic (18)F-FDG PET/CT. PET parameters including maximum and average standardized uptake values (SUVmax, SUVave), metabolic tumor volume (MTV), and total lesion glycolysis (TLG) of the primary tumor were measured using a threshold SUV to determine the boundaries of the tumors. Univariate and multivariate survival analyses were performed with adjustments for PET parameters and other clinical values.
  
  
  RESULTS
  The median clinical follow-up was 22.3 (range, 1.2-95.4) months. Cancer-related death occurred in 5 of 20 patients (25 %). Patients had clinical or pathological stages of I in seven patients, II in six patients, III in three patient, and IV in four patients. According to the WHO histological classification of subtypes, 3 patients exhibited well-differentiated PNETs, 13 patients had well-differentiated endocrine carcinomas, and 4 had poorly differentiatedendocrine carcinomas. Univariate analysis showed that tumor size (p = 0.028), AJCC stage (p = 0.009), T stage (p = 0.028), M stage (p = 0.029), treatment modality (p = 0.045), MTV (p = 0.003) and TLG (p = 0.027) were significant predictors of overall survival. On multivariate analysis, MTV (HR = 10.859, p = 0.031) was a significant independent predictor of overall survival along with the AJCC stage (HR = 11.556, p = 0.027).
  
  
  CONCLUSIONS
  In patients with PNETs, the MTV of the primary tumor as measured by (18)F-FDG PET/CT along with the AJCC stage may be a significant independent prognostic factor for overall survival.
authors.affiliation: Department of Nuclear Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, 50 Irwon-dong, Gangnam-gu, Seoul, 135-710 Republic of Korea.
authors.forename: Ho Seong
authors.initials: HS
authors.lastname: Kim
authors.affiliation: Department of Nuclear Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, 50 Irwon-dong, Gangnam-gu, Seoul, 135-710 Republic of Korea.
authors.forename: Joon Young
authors.initials: JY
authors.lastname: Choi
authors.affiliation: Department of Surgery, Samsung Medical Center, Sungkyunkwan University School of Medicine, 50 Irwon-dong, Gangnam-gu, Seoul, 135-710 Republic of Korea.
authors.forename: Dong Wook
authors.initials: DW
authors.lastname: Choi
authors.affiliation: Department of Internal Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, 50 Irwon-dong, Gangnam-gu, Seoul, 135-710 Republic of Korea.
authors.forename: Ho Yeong
authors.initials: HY
authors.lastname: Lim
authors.affiliation: Department of Nuclear Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, 50 Irwon-dong, Gangnam-gu, Seoul, 135-710 Republic of Korea.
authors.forename: Joo Hee
authors.initials: JH
authors.lastname: Lee
authors.affiliation: Department of Nuclear Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, 50 Irwon-dong, Gangnam-gu, Seoul, 135-710 Republic of Korea.
authors.forename: Sun Pyo
authors.initials: SP
authors.lastname: Hong
authors.affiliation: Department of Nuclear Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, 50 Irwon-dong, Gangnam-gu, Seoul, 135-710 Republic of Korea.
authors.forename: Young Seok
authors.initials: YS
authors.lastname: Cho
authors.affiliation: Department of Nuclear Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, 50 Irwon-dong, Gangnam-gu, Seoul, 135-710 Republic of Korea.
authors.forename: Kyung-Han
authors.initials: KH
authors.lastname: Lee
authors.affiliation: Department of Nuclear Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, 50 Irwon-dong, Gangnam-gu, Seoul, 135-710 Republic of Korea.
authors.forename: Byung-Tae
authors.initials: BT
authors.lastname: Kim
keywords: 18F-FDG PET/CT; Metabolic tumor volume; Pancreatic neuroendocrine tumor; Prognosis; Total lesion glycolysis