title: Increased tumour ADC value during chemotherapy predicts improved survival in unresectable pancreatic cancer.
abstract: OBJECTIVE
  To investigate whether changes to the apparent diffusion coefficient (ADC) of primary tumour in the early period after starting chemotherapy can predict progression-free survival (PFS) or overall survival (OS) in patients with unresectable pancreatic adenocarcinoma.
  
  
  METHODS
  Subjects comprised 43 patients with histologically confirmed unresectable pancreatic cancer treated with first-line chemotherapy. Minimum ADC values in primary tumour were measured using the selected area ADC (sADC), which excluded cystic and necrotic areas and vessels, and the whole tumour ADC (wADC), which included whole tumour components. Relative changes in ADC were calculated from baseline to 4 weeks after initiation of chemotherapy. Relationships between ADC and both PFS and OS were modelled by Cox proportional hazards regression.
  
  
  RESULTS
  Median PFS and OS were 6.1 and 11.0 months, respectively. In multivariate analysis, sADC change was the strongest predictor of PFS (hazard ratio (HR), 4.5; 95 % confidence interval (CI), 1.7-11.9; p = 0.002). Multivariate Cox regression analysis for OS revealed sADC change and CRP as independent predictive markers, with sADC change as the strongest predictive biomarker (HR, 6.7; 95 % CI, 2.7-16.6; p = 0.001).
  
  
  CONCLUSIONS
  Relative changes in sADC could provide a useful imaging biomarker to predict PFS and OS with chemotherapy for unresectable pancreatic adenocarcinoma.
  
  
  CONCLUSIONS
  • Relative change in ADC value can predict survival in unresectable pancreatic cancer. • ADC change could determine a chemosensitivity of pancreatic cancer. • ADC values should be measured by excluding cystic, necrotic areas and vessels.
authors.affiliation: Department of Radiology and IVR Center, Nara Medical University, Kashihara-city, Nara, 634-8522, Japan. hmn@naramed-u.ac.jp.
authors.forename: Hideyuki
authors.initials: H
authors.lastname: Nishiofuku
authors.affiliation: Department of Radiology and IVR Center, Nara Medical University, Kashihara-city, Nara, 634-8522, Japan.
authors.forename: Toshihiro
authors.initials: T
authors.lastname: Tanaka
authors.affiliation: Department of Endoscopy and Ultrasound, Nara Medical University, Kashihara-city, Nara, 634-8522, Japan.
authors.forename: Nagaaki
authors.initials: N
authors.lastname: Marugami
authors.affiliation: Department of Surgery, Nara Medical University, Kashihara-city, Nara, 634-8522, Japan.
authors.forename: Masayuki
authors.initials: M
authors.lastname: Sho
authors.affiliation: Department of Surgery, Nara Medical University, Kashihara-city, Nara, 634-8522, Japan.
authors.forename: Takahiro
authors.initials: T
authors.lastname: Akahori
authors.affiliation: Department of Surgery, Nara Medical University, Kashihara-city, Nara, 634-8522, Japan.
authors.forename: Yoshiyuki
authors.initials: Y
authors.lastname: Nakajima
authors.affiliation: Department of Radiology and IVR Center, Nara Medical University, Kashihara-city, Nara, 634-8522, Japan.
authors.forename: Kimihiko
authors.initials: K
authors.lastname: Kichikawa
mesh_terms: D000230:Adenocarcinoma / Q000000981:diagnostic imaging* / Q000188:drug therapy*; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000970:Antineoplastic Agents / Q000627:therapeutic use*; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods; D005260:Female; D006801:Humans; D007090:Image Interpretation, Computer-Assisted / Q000379:methods; D053208:Kaplan-Meier Estimate; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D010190:Pancreatic Neoplasms / Q000000981:diagnostic imaging* / Q000188:drug therapy*; D011379:Prognosis; D016016:Proportional Hazards Models; D011446:Prospective Studies; D012044:Regression Analysis; D016896:Treatment Outcome
chemical_list: D000970:Antineoplastic Agents
keywords: Apparent diffusion coefficient; Biomarker; MRI; Pancreatic cancer; Prognostic factor