title: Application of an unsupervised multi-characteristic framework for intermediate-high risk prostate cancer localization using diffusion-weighted MRI.
abstract: The aim of this proof-of-concept work is to propose an unsupervised framework that combines multiple parameters, in "positive-if-all-positive" manner, from different models to localize tumors.
  
  
  
  A voxel-by-voxel analysis of the DW-MRI images of whole prostate was performed to obtain parametric maps for D*, D, f, and K using the IVIM and kurtosis models. Ten patients with moderate or high-risk prostate cancer were included in study. The mean age and serum PSA for these 10 patients were 65years (range 54-78) and 21.9ng/mL (range 4.84-44.81), respectively. These patients were scanned using a DW spin-echo sequence with echo-planar readout with 16 equidistantly spaced b-values in the range of 0-2000s/mm2(TE=58ms; TR=3990ms; spatial resolution 2.19×2.19×2.73mm3, slices =26, FOV=140×140mm, slice gap =0.27mm, NSA=2).
  
  
  
  The proposed framework detected 24 lesions of which 14 were true positive with 58% tumor detection rate on lesion-based analysis with sensitivity of 100%. The mpMRI evaluation (PIRADSv2) identified 12 of 14 true positive lesions with sensitivity of 86%; positive predictive value of mpMRI was 92%. The index lesions were visible on all framework maps and were coded as the most suspicious in 9 of 10 patients.
  
  
  
  Preliminary results of the proposed framework indicate high patient-based sensitivity with 100% detection rate for identifying moderate-high risk aggressive index lesions.
authors.affiliation: Division of Computational Bioscience, CIT, NIH, Bethesda, MD, USA. Electronic address: raisa@mail.nih.gov.
authors.forename: Raisa Z
authors.initials: RZ
authors.lastname: Freidlin
authors.affiliation: Molecular Imaging Program, NCI, NIH, Bethesda, MD, USA; Philips Research North America, Briarcliff Manor NY, USA.
authors.forename: Harsh K
authors.initials: HK
authors.lastname: Agarwal
authors.affiliation: Molecular Imaging Program, NCI, NIH, Bethesda, MD, USA.
authors.forename: Sandeep
authors.initials: S
authors.lastname: Sankineni
authors.affiliation: Molecular Imaging Program, NCI, NIH, Bethesda, MD, USA; Duke University School of Medicine, Durham, NC, USA.
authors.forename: Anna M
authors.initials: AM
authors.lastname: Brown
authors.affiliation: Molecular Imaging Program, NCI, NIH, Bethesda, MD, USA.
authors.forename: Francesca
authors.initials: F
authors.lastname: Mertan
authors.affiliation: Molecular Imaging Program, NCI, NIH, Bethesda, MD, USA; Leidos Biomedical Research, Inc., Frederick National Laboratory for Cancer Research, MD, USA.
authors.forename: Marcelino
authors.initials: M
authors.lastname: Bernardo
authors.affiliation: Molecular Imaging Program, NCI, NIH, Bethesda, MD, USA; Leidos Biomedical Research, Inc., Frederick National Laboratory for Cancer Research, MD, USA.
authors.forename: Dagane
authors.initials: D
authors.lastname: Daar
authors.affiliation: Laboratory of Pathology, NCI, NIH, Bethesda, MD, USA.
authors.forename: Maria
authors.initials: M
authors.lastname: Merino
authors.affiliation: Radiation Oncology Branch, NCI, NIH, Bethesda, MD, USA.
authors.forename: Deborah
authors.initials: D
authors.lastname: Citrin
authors.affiliation: Center for Interventional Oncology, NCI and Radiology and Imaging Sciences, Clinical Center, NIH, Bethesda, MD, USA.
authors.forename: Bradford J
authors.initials: BJ
authors.lastname: Wood
authors.affiliation: Urologic Oncology Branch, NCI, NIH, Bethesda, MD, USA.
authors.forename: Peter A
authors.initials: PA
authors.lastname: Pinto
authors.affiliation: Molecular Imaging Program, NCI, NIH, Bethesda, MD, USA.
authors.forename: Peter L
authors.initials: PL
authors.lastname: Choyke
authors.affiliation: Molecular Imaging Program, NCI, NIH, Bethesda, MD, USA.
authors.forename: Baris
authors.initials: B
authors.lastname: Turkbey
mesh_terms: D000368:Aged; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods*; D006801:Humans; D008297:Male; D008875:Middle Aged; D011467:Prostate / Q000000981:diagnostic imaging / Q000473:pathology; D011471:Prostatic Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
keywords: DWI; Diffusion-weighted MRI; Prostate cancer; Tumor localization