title: The role of pathology correlation approach in prostate cancer index lesion detection and quantitative analysis with multiparametric MRI.
abstract: OBJECTIVE
  Development of imaging biomarkers often relies on their correlation with histopathology. Our aim was to compare two approaches for correlating pathology to multiparametric magnetic resonance (MR) imaging (mpMRI) for localization and quantitative assessment of prostate cancer (PCa) index tumor using whole mount (WM) pathology (WMP) as the reference.
  
  
  METHODS
  Patients (N = 30) underwent mpMRI that included diffusion-weighted imaging and dynamic contrast-enhanced (DCE) MRI at 3 T before radical prostatectomy (RP). RP specimens were processed using WM technique (WMP) and findings summarized in a standard surgical pathology report (SPR). Histology index tumor volumes (HTVs) were compared to MR tumor volumes (MRTVs) using two approaches for index lesion identification on mpMRI using annotated WMP slides as the reference (WMP) and using routine SPR as the reference. Consistency of index tumor localization, tumor volume, and mean values of the derived quantitative parameters (mean apparent diffusion coefficient [ADC], K(trans), and ve) were compared.
  
  
  RESULTS
  Index lesions from 16 of 30 patients met the selection criteria. There was WMP/SRP agreement in index tumor in 13 of 16 patients. ADC-based MRTVs were larger (P < .05) than DCE-based MRTVs. ADC MRTVs were smaller than HTV (P < .005). There was a strong correlation between HTV and MRTV (Pearson ρ > 0.8; P < .05). No significant differences were observed in the mean values of K(trans) and ADC between the WMP and SPR.
  
  
  CONCLUSIONS
  WMP correlation is superior to SPR for accurate localization of all index lesions. The use of WMP is however not required to distinguish significant differences of mean values of quantitative MRI parameters within tumor volume.
authors: Department of Radiology, Brigham and Women's Hospital, 75 Francis Street, Boston, MA 02115.
authors: Andriy
authors: A
authors: Fedorov
authors: Department of Radiology, Brigham and Women's Hospital, 75 Francis Street, Boston, MA 02115; Department of Radiology, RWTH Aachen University Hospital, Aachen, Germany.
authors: Tobias
authors: T
authors: Penzkofer
authors: Department of Pathology, Brigham and Women's Hospital, Boston, Massachusetts.
authors: Michelle S
authors: MS
authors: Hirsch
authors: Department of Pathology, Brigham and Women's Hospital, Boston, Massachusetts.
authors: Trevor A
authors: TA
authors: Flood
authors: Department of Radiology, Massachusetts General Hospital, Boston, Massachusetts.
authors: Mark G
authors: MG
authors: Vangel
authors: Department of Pathology, Brigham and Women's Hospital, Boston, Massachusetts.
authors: Paul
authors: P
authors: Masry
authors: Department of Radiology, Brigham and Women's Hospital, 75 Francis Street, Boston, MA 02115.
authors: Clare M
authors: CM
authors: Tempany
authors: Department of Radiology, Boston Children's Hospital, Boston, Massachusetts.
authors: Robert V
authors: RV
authors: Mulkern
authors: Department of Radiology, Brigham and Women's Hospital, 75 Francis Street, Boston, MA 02115; Department of Radiology, Dana-Farber Cancer Institute, Boston, Massachusetts. Electronic address: ffennessy@partners.org.
authors: Fiona M
authors: FM
authors: Fennessy
mesh_terms: D000368:Aged; D001706:Biopsy; D003287:Contrast Media; D038524:Diffusion Magnetic Resonance Imaging; D019786:Gadolinium DTPA; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D060787:Neoplasm Grading; D017430:Prostate-Specific Antigen / Q000097:blood; D011468:Prostatectomy; D011471:Prostatic Neoplasms / Q000097:blood / Q000473:pathology* / Q000601:surgery; D047368:Tumor Burden
chemical_list: D003287:Contrast Media; D017430:Prostate-Specific Antigen; D019786:Gadolinium DTPA
keywords: Prostate cancer; magnetic resonance imaging; pathology correlation; quantitative imaging