title: Prostate tumor volume measurement with combined T2-weighted imaging and diffusion-weighted MR: correlation with pathologic tumor volume.
abstract: OBJECTIVE
  To retrospectively determine the accuracy of diffusion-weighted (DW) magnetic resonance (MR) imaging for identifying cancer in the prostate peripheral zone (PZ) and to assess the accuracy of tumor volume measurements made with T2-weighted imaging and combined T2-weighted and DW MR imaging by using surgical pathologic examination as the reference standard.
  
  
  METHODS
  The institutional review board issued a waiver of informed consent for this HIPAA-compliant study. Forty-two patients underwent endorectal MR at 1.5 T before undergoing radical prostatectomy for prostate cancer and had at least one PZ tumor larger than 0.1 cm(3) at surgical pathologic examination. On T2-weighted images, an experienced radiologist outlined suspected PZ tumors. Two apparent diffusion coefficient (ADC) cutoff values were identified by using the Youden index and published literature. Image cluster analysis was performed on voxels within the suspected tumor regions. Associations between volume measurements from imaging and from pathologic examination were assessed by using concordance correlation coefficients (CCCs). The sensitivity and specificity of ADCs for identifying malignant PZ voxels were calculated.
  
  
  RESULTS
  In identifying malignant voxels, respective ADC cutoff values of 0.0014 and 0.0016 mm(2)/sec yielded sensitivity of 82% and 95% and specificity of 85% and 65%, respectively. Sixty PZ cancer lesions larger than 0.1 cm(3) were found at pathologic examination; 43 were detected by the radiologist. CCCs between imaging and pathologic tumor volume measurements were 0.36 for T2-weighted imaging, and 0.46 and 0.60 for combined T2-weighted and DW MR imaging with ADC cutoffs of 0.0014 and 0.0016 mm(2)/sec, respectively; the CCC of combined T2-weighted and DW MR imaging (ADC cutoff, 0.0016 mm(2)/sec) was significantly higher (P = .006) than that of T2-weighted imaging alone.
  
  
  CONCLUSIONS
  Adding DW MR to T2-weighted imaging can significantly improve the accuracy of prostate PZ tumor volume measurement.
  
  
  BACKGROUND
  http://radiology.rsnajnls.org/cgi/content/full/252/2/449/DC1.
authors.affiliation: Department of Medical Physics, Memorial Sloan-Kettering Cancer Center, 1275 York Ave, Room C-278, New York, NY 10065, USA. hricakh@mskcc.org
authors.forename: Yousef
authors.initials: Y
authors.lastname: Mazaheri
authors.forename: Hedvig
authors.initials: H
authors.lastname: Hricak
authors.forename: Samson W
authors.initials: SW
authors.lastname: Fine
authors.forename: Oguz
authors.initials: O
authors.lastname: Akin
authors.forename: Amita
authors.initials: A
authors.lastname: Shukla-Dave
authors.forename: Nicole M
authors.initials: NM
authors.lastname: Ishill
authors.forename: Chaya S
authors.initials: CS
authors.lastname: Moskowitz
authors.forename: Joanna E
authors.initials: JE
authors.lastname: Grater
authors.forename: Victor E
authors.initials: VE
authors.lastname: Reuter
authors.forename: Kristen L
authors.initials: KL
authors.lastname: Zakian
authors.forename: Karim A
authors.initials: KA
authors.lastname: Touijer
authors.forename: Jason A
authors.initials: JA
authors.lastname: Koutcher
mesh_terms: D000328:Adult; D000368:Aged; 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; D009929:Organ Size; D011471:Prostatic Neoplasms / Q000473:pathology*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013223:Statistics as Topic
references.citation: Lancet. 1986 Feb 8;1(8476):307-10
references.pmid: 2868172
references.citation: J Urol. 1988 Jun;139(6):1235-41
references.pmid: 3373594
references.citation: Clin Radiol. 2008 Jul;63(7):774-82
references.pmid: 18555035
references.citation: J Urol. 2002 Nov;168(5):2011-5
references.pmid: 12394697
references.citation: J Urol. 1990 Jun;143(6):1155-62
references.pmid: 1692886
references.citation: Urology. 1998 Oct;52(4):653-8
references.pmid: 9763088
references.citation: J Urol. 1990 Jun;143(6):1183-7
references.pmid: 2342179
references.citation: Urology. 1993 May;41(5):403-11
references.pmid: 8488608
references.citation: Comput Biomed Res. 1996 Jun;29(3):162-73
references.pmid: 8812068
references.citation: Curr Opin Urol. 2008 Jan;18(1):71-7
references.pmid: 18090494
references.citation: Eur Urol. 1997;32(2):140-9
references.pmid: 9286643
references.citation: Br J Radiol. 2007 Feb;80(950):90-5
references.pmid: 17303616
references.citation: J Comput Assist Tomogr. 2005 Mar-Apr;29(2):149-53
references.pmid: 15772529
references.citation: AJR Am J Roentgenol. 2007 Aug;189(2):323-8
references.pmid: 17646457
references.citation: Am J Surg Pathol. 1990 Mar;14(3):240-7
references.pmid: 2305930
references.citation: AJR Am J Roentgenol. 2007 Jun;188(6):1622-35
references.pmid: 17515386
references.citation: J Magn Reson Imaging. 2005 Mar;21(3):258-62
references.pmid: 15723379
references.citation: Hum Pathol. 1992 Mar;23(3):258-66
references.pmid: 1555836
references.citation: J Urol. 2006 Dec;176(6 Pt 1):2432-7
references.pmid: 17085122
references.citation: Med Phys. 2003 Sep;30(9):2390-8
references.pmid: 14528961
references.citation: Eur Urol. 1999 Jan;35(1):32-5
references.pmid: 9933792
references.citation: Radiology. 1989 Dec;173(3):847-51
references.pmid: 2479050
references.citation: J Urol. 1993 Jun;149(6):1478-81
references.pmid: 8501792
references.citation: J Magn Reson Imaging. 2008 Jan;27(1):132-9
references.pmid: 18050334
references.citation: J Urol. 2004 Aug;172(2):508-11
references.pmid: 15247716
references.citation: AJR Am J Roentgenol. 1993 Jul;161(1):81-6
references.pmid: 8517328
references.citation: Eur Urol. 2006 Dec;50(6):1163-74; discussion 1175
references.pmid: 16842903
references.citation: Cancer Imaging. 2006 Sep 13;6:135-43
references.pmid: 17015238
references.citation: Radiology. 2002 Apr;223(1):91-7
references.pmid: 11930052
references.citation: J Biopharm Stat. 2007;17(4):721-38
references.pmid: 17613650
references.citation: Biometrics. 1977 Mar;33(1):159-74
references.pmid: 843571
references.citation: J Urol. 1996 Jan;155(1):232-7
references.pmid: 7490842
references.citation: Urology. 1997 Mar;49(3):385-91
references.pmid: 9123703
references.citation: Radiology. 1988 Aug;168(2):497-505
references.pmid: 3393671
references.citation: Cancer. 1990 Sep 15;66(6):1225-33
references.pmid: 2400973
references.citation: AJR Am J Roentgenol. 1996 Apr;166(4):845-52
references.pmid: 8610561
references.citation: Biometrics. 1989 Mar;45(1):255-68
references.pmid: 2720055
references.citation: Radiology. 2008 Feb;246(2):480-8
references.pmid: 18227542