title: Prognostic Value of FDG PET/CT-Derived Parameters in Pancreatic Adenocarcinoma at Initial PET/CT Staging.
abstract: OBJECTIVE
  The purpose of this study is to evaluate the performance of PET-derived parameters as prognostic markers for overall survival (OS) and progression-free survival (PFS) outcome in patients with pancreatic adenocarcinoma.
  
  
  METHODS
  We conducted a retrospective study of 106 patients (62 men and 44 women) with histologically proven pancreatic adenocarcinoma who underwent initial staging FDG PET/CT before treatment. Peak standardized uptake value (SUV), maximum SUV (SUVmax), metabolic tumor volume, and tumor glycolytic activity of the primary pancreatic tumor were measured. Two segmentation methods were performed to obtain the metabolic tumor volume and tumor glycolytic activity for all tumors: a gradient-based segmentation model (metabolic tumor volume and tumor glycolytic activity by gradient edge detection) and a fixed-threshold model with a threshold of 50% of the lesion's SUVmax and peak SUV. Univariate and multivariate Cox regression models were developed including clinical and imaging parameters for OS and PFS.
  
  
  RESULTS
  Multivariate Cox regression analysis showed a statistically significant association between PFS and age, SUVmax, peak SUV, and tumor glycolytic activity by gradient edge detection. There was a statistically significant difference in PFS for patients with values above and below the median cutoff points for SUVmax (hazard ratio [HR], 1.12; p < 0.01), peak SUV (HR, 1.25; p < 0.02), and tumor glycolytic activity measured by gradient edge detection (HR, 1.00; p < 0.02) of the primary tumor. However, multivariate Cox regression analysis showed a statistically significant association only between tumor glycolytic activity by gradient edge detection and OS (p = 0.04), and there was a statistically significant difference in OS between patients with values above and below the median cutoff point for the tumor glycolytic activity by gradient edge detection of the primary tumor (HR, 1.42; p = 0.05).
  
  
  CONCLUSIONS
  Age, SUVmax, peak SUV, and total lesion glycolysis (i.e., tumor glycolytic activity) of the primary tumor are associated with PFS, and tumor glycolytic activity is associated with OS in patients with pancreatic adenocarcinoma.
authors.affiliation: 1 Russell H. Morgan Department of Radiology and Radiological Sciences, Johns Hopkins University, 601 N Caroline St, JHOC 3235, Baltimore, MD 21287.
authors.forename: Alin
authors.initials: A
authors.lastname: Chirindel
authors.forename: Krishna C
authors.initials: KC
authors.lastname: Alluri
authors.forename: Muhammad A
authors.initials: MA
authors.lastname: Chaudhry
authors.forename: Richard L
authors.initials: RL
authors.lastname: Wahl
authors.forename: Timothy M
authors.initials: TM
authors.lastname: Pawlik
authors.forename: Joseph M
authors.initials: JM
authors.lastname: Herman
authors.forename: Rathan M
authors.initials: RM
authors.lastname: Subramaniam
mesh_terms: D000230:Adenocarcinoma / Q000000981:diagnostic imaging* / Q000473:pathology; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D019788:Fluorodeoxyglucose F18; D006801:Humans; D008297:Male; D008875:Middle Aged; D064847:Multimodal Imaging; D009367:Neoplasm Staging; D010190:Pancreatic Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology; D049268:Positron-Emission Tomography; D011379:Prognosis; D011857:Radiographic Image Interpretation, Computer-Assisted; D019275:Radiopharmaceuticals; D012189:Retrospective Studies; D015996:Survival Rate; D014057:Tomography, X-Ray Computed; D047368:Tumor Burden
chemical_list: D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18
keywords: FDG volumetric parameters; metabolic tumor volume; outcome; pancreatic adenocarcinoma; tumor glycolytic activity