title: Restricted water diffusibility as measured by diffusion-weighted MR imaging and choline uptake in (11)C-choline PET/CT are correlated in pelvic lymph nodes in patients with prostate cancer.
abstract: OBJECTIVE
  (11)C-Choline-positron emission tomography (PET)/computed tomography (CT) is increasingly used in patients with prostate cancer. Another promising technique for assessment of tumor biology is diffusion-weighted MR imaging (DWI). The aim of the study was to compare the functional parameters standardized uptake value (SUV) in PET and apparent diffusion coefficient (ADC) value in DWI of lymph nodes in prostate cancer patients.
  
  
  METHODS
  Fourteen patients with prostate cancer underwent DWI at 1.5T and (11)C-Choline-PET/CT. ADC values and SUVs of all lymph nodes larger than 5 mm (n = 55) were compared by using linear regression analysis. Performance of DWI and (11)C-Choline PET was assessed by receiver operator characteristic curve analysis using histopathology or clinical follow-up as standard of reference.
  
  
  RESULTS
  ADC values and SUV showed a moderate but highly significant inverse correlation (r = -0.5144, p < 0.0001). In lymph nodes with low ADC values, the dispersion of SUV was more pronounced. Moreover, a highly significant difference was observed for mean ADC values and SUV in lymph nodes considered as benign or malignant by follow-up/histopathology (ADC 1.60 ± 0.24 vs. 1.09 ± 0.23 × 10(-3) mm(2)/s; SUV 1.82 ± 0.57 vs. 4.68 ± 03.12; p < 0.0001, respectively).
  
  
  CONCLUSIONS
  These pilot data propose the ADC value in DWI as a new potential imaging biomarker which might provide additional information on tumor pathophysiology compared to the SUV in (11)C-Choline PET/CT.
authors.affiliation: Department of Nuclear Medicine, Klinikum rechts der Isar, Technische Universität München, Ismaninger Str. 22, 81675, Munich, Germany.
authors.forename: Ambros J
authors.initials: AJ
authors.lastname: Beer
authors.forename: Matthias
authors.initials: M
authors.lastname: Eiber
authors.forename: Michael
authors.initials: M
authors.lastname: Souvatzoglou
authors.forename: Konstantin
authors.initials: K
authors.lastname: Holzapfel
authors.forename: Carl
authors.initials: C
authors.lastname: Ganter
authors.forename: Gregor
authors.initials: G
authors.lastname: Weirich
authors.forename: Tobias
authors.initials: T
authors.lastname: Maurer
authors.forename: Hubert
authors.initials: H
authors.lastname: Kübler
authors.forename: Hans-Juergen
authors.initials: HJ
authors.lastname: Wester
authors.forename: Jochen
authors.initials: J
authors.lastname: Gaa
authors.forename: Bernd J
authors.initials: BJ
authors.lastname: Krause
mesh_terms: D000368:Aged; D002250:Carbon Radioisotopes; D002794:Choline / Q000493:pharmacokinetics*; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods*; D005500:Follow-Up Studies; D006801:Humans; D008198:Lymph Nodes / Q000000981:diagnostic imaging / Q000473:pathology*; D008207:Lymphatic Metastasis; D008297:Male; D008875:Middle Aged; D010388:Pelvis / Q000469:parasitology*; D049268:Positron-Emission Tomography; D017430:Prostate-Specific Antigen / Q000378:metabolism; D011471:Prostatic Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology; D012372:ROC Curve; D014057:Tomography, X-Ray Computed; D014867:Water / Q000737:chemistry*
chemical_list: D002250:Carbon Radioisotopes; D014867:Water; D017430:Prostate-Specific Antigen; D002794:Choline