title: Non-invasive estimation of prostate cancer aggressiveness using diffusion-weighted MRI and 3D proton MR spectroscopy at 3.0 T.
abstract: BACKGROUND
  Clinical management of prostate cancer increasingly aims to distinguish aggressive types that require immediate and radical treatment from indolent tumors that are candidates for watchful waiting. This requires reliable and reproducible parameters to effectively control potential cancer progression. Magnetic resonance imaging (MRI) may provide a non-invasive means for this purpose.
  
  
  OBJECTIVE
  To assess the value of diffusion-weighted imaging and proton MR spectroscopy for the prediction of prostate cancer (PCa) aggressiveness.
  
  
  METHODS
  In 39 of 64 consecutive patients who underwent endorectal 3-T MRI prior to radical prostatectomy, prostate specimens were analyzed as whole-mount step sections. Apparent diffusion coefficient (ADC), normalized ADC (nADC: tumor/healthy tissue), choline/citrate (CC), and (choline + creatine)/citrate (CCC) ratios were correlated with Gleason scores (GS) from histopathological results. The power to discriminate low (GS ≤ 6) from higher-risk (GS ≥ 7) tumors was assessed with receiver operating characteristics (area under the curve [AUC]). Resulting threshold values were used by a blinded reader to distinguish between aggressive and indolent tumors.
  
  
  RESULTS
  Ninety lesions (1 × GS = 5, 41 × GS = 6, 36 × GS = 7, 12 × GS = 8) were considered. nADC (AUC = 0.90) showed a higher discriminatory power than ADC (AUC = 0.79). AUC for CC and CCC were 0.73 and 0.82, respectively. Using either nADC < 0.46 or CCC > 1.3, as well as both criteria for aggressive PCa, the reader correctly identified aggressive and indolent tumors in 31 (79%), 28 (72%), and 33 of 39 patients (85%), respectively. Predictions of tumor aggressiveness from TRUS-guided biopsies were correct in 27 of 36 patients (75%).
  
  
  CONCLUSIONS
  The combination of a highly sensitive normalized ADC with a highly specific CCC was found to be well suited to prospectively estimate PCa aggressiveness with a similar diagnostic accuracy as biopsy results.
authors: Department of Diagnostic and Interventional Radiology, Leipzig University Hospital, Leipzig, Germany.
authors: Gregor
authors: G
authors: Thörmer
authors: Department of Diagnostic and Interventional Radiology, Leipzig University Hospital, Leipzig, Germany.
authors: Josephin
authors: J
authors: Otto
authors: Institute of Pathology, University of Leipzig, Leipzig, Germany.
authors: Lars-Christian
authors: LC
authors: Horn
authors: Department of Diagnostic and Interventional Radiology, Leipzig University Hospital, Leipzig, Germany.
authors: Nikita
authors: N
authors: Garnov
authors: Department of Urology, Leipzig University Hospital, Leipzig, Germany.
authors: Minh
authors: M
authors: Do
authors: Department of Urology, Leipzig University Hospital, Leipzig, Germany.
authors: Toni
authors: T
authors: Franz
authors: Department of Urology, Leipzig University Hospital, Leipzig, Germany.
authors: Jens-Uwe
authors: JU
authors: Stolzenburg
authors: Department of Diagnostic and Interventional Radiology, Leipzig University Hospital, Leipzig, Germany.
authors: Michael
authors: M
authors: Moche
authors: Department of Diagnostic and Interventional Radiology, Leipzig University Hospital, Leipzig, Germany.
authors: Thomas
authors: T
authors: Kahn
authors: Department of Diagnostic and Interventional Radiology, Leipzig University Hospital, Leipzig, Germany harald.busse@medizin.uni-leipzig.de.
authors: Harald
authors: H
authors: Busse
mesh_terms: D000368:Aged; D014408:Biomarkers, Tumor / Q000032:analysis*; D002794:Choline / Q000032:analysis*; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods*; D006801:Humans; D007090:Image Interpretation, Computer-Assisted / Q000379:methods; D021621:Imaging, Three-Dimensional / Q000379:methods*; D008297:Male; D008875:Middle Aged; D057054:Molecular Imaging / Q000379:methods; D009361:Neoplasm Invasiveness; D015588:Observer Variation; D011471:Prostatic Neoplasms / Q000737:chemistry* / Q000175:diagnosis*; D066244:Proton Magnetic Resonance Spectroscopy / Q000379:methods*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
chemical_list: D014408:Biomarkers, Tumor; D002794:Choline
keywords: MR diffusion/perfusion; MR spectroscopy; Magnetic resonance imaging (MRI); prostate; staging