title: Prognostic relevance of apparent diffusion coefficient obtained by diffusion-weighted MRI in pancreatic cancer.
abstract: BACKGROUND
  Diffusion-weighted magnetic resonance imaging (DW-MRI) is utilized as a method of oncologic imaging for predicting treatment outcomes. This study explored the role of DW-MRI in the treatment of patients with resected pancreatic cancer by comparing apparent diffusion coefficient (ADC) values with clinicopathological findings and survival rates.
  
  
  METHODS
  Records of 54 patients in whom DW-MRI at 1.5T was performed (b values: 0 and 1000 mm(2) /s) before macroscopically curative resection were analyzed. ADC values were then calculated and compared with clinicopathological factors including age, gender, serum carcinoembryonic antigen levels, serum carbohydrate antigen 19-9 levels, lymph node metastasis, primary tumoral location, size, differentiation, resectability, and pT stage. A survival analysis of clinicopathological factors and ADC values was performed using the Kaplan-Meier method, and the results were evaluated with the log-rank test. Prognostic significance was assessed using the Cox proportional hazard model.
  
  
  RESULTS
  Significant associations were found between tumor differentiation and ADC values (P = 0.001). In a univariate analysis of overall survival, tumor differentiation (P = 0.037) and ADC values (P = 0.002) were identified as significant prognostic factors. However, age, gender, carcinoembryonic antigen levels, carbohydrate antigen 19-9 levels, lymph node metastasis, primary tumoral location, size, resectability, and pT stage were not associated with overall survival. In a multivariate analysis of overall survival, only ADC values were identified as significant prognostic factors (hazard ratio 2.293, 95% confidence interval 1.147-4.585, P = 0.019).
  
  
  CONCLUSIONS
  ADC values were found to be associated with prognosis in patients with resected pancreatic cancer.
authors.affiliation: Department of Gastroenterology and Nephrology, Graduate School of Medicine, Chiba University, Chiba, Japan.
authors.forename: Jo
authors.initials: J
authors.lastname: Kurosawa
authors.affiliation: Department of Gastroenterology and Nephrology, Graduate School of Medicine, Chiba University, Chiba, Japan.
authors.forename: Katsunobu
authors.initials: K
authors.lastname: Tawada
authors.affiliation: Department of Gastroenterology and Nephrology, Graduate School of Medicine, Chiba University, Chiba, Japan.
authors.forename: Rintaro
authors.initials: R
authors.lastname: Mikata
authors.affiliation: Department of Gastroenterology and Nephrology, Graduate School of Medicine, Chiba University, Chiba, Japan.
authors.forename: Takeshi
authors.initials: T
authors.lastname: Ishihara
authors.affiliation: Department of Gastroenterology and Nephrology, Graduate School of Medicine, Chiba University, Chiba, Japan.
authors.forename: Toshio
authors.initials: T
authors.lastname: Tsuyuguchi
authors.affiliation: Department of Gastroenterology and Nephrology, Graduate School of Medicine, Chiba University, Chiba, Japan.
authors.forename: Masayoshi
authors.initials: M
authors.lastname: Saito
authors.affiliation: Department of Radiology, Graduate School of Medicine, Chiba University, Chiba, Japan.
authors.forename: Ryota
authors.initials: R
authors.lastname: Shimofusa
authors.affiliation: Department of General Surgery, Graduate School of Medicine, Chiba University, Chiba, Japan.
authors.forename: Hideyuki
authors.initials: H
authors.lastname: Yoshitomi
authors.affiliation: Department of General Surgery, Graduate School of Medicine, Chiba University, Chiba, Japan.
authors.forename: Masayuki
authors.initials: M
authors.lastname: Ohtsuka
authors.affiliation: Department of General Surgery, Graduate School of Medicine, Chiba University, Chiba, Japan.
authors.forename: Masaru
authors.initials: M
authors.lastname: Miyazaki
authors.affiliation: Department of Gastroenterology and Nephrology, Graduate School of Medicine, Chiba University, Chiba, Japan.
authors.forename: Osamu
authors.initials: O
authors.lastname: Yokosuka
mesh_terms: D017677:Age Distribution; D000368:Aged; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods*; D005260:Female; D006801:Humans; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D007564:Japan / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D010190:Pancreatic Neoplasms / Q000401:mortality* / Q000473:pathology* / Q000601:surgery; D015995:Prevalence; D011379:Prognosis; D016016:Proportional Hazards Models; D015203:Reproducibility of Results; D012307:Risk Factors; D012680:Sensitivity and Specificity; D017678:Sex Distribution; D015996:Survival Rate; D016896:Treatment Outcome
keywords: ADC; pancreatic cancer; prognostic factor