title: Prostate cancer: sextant localization with MR imaging, MR spectroscopy, and 11C-choline PET/CT.
abstract: OBJECTIVE
  To retrospectively compare sensitivity and specificity of magnetic resonance (MR) imaging, three-dimensional (3D) MR spectroscopy, combined MR imaging and 3D MR spectroscopy, and carbon 11 (11C)-choline positron emission tomography (PET)/computed tomography (CT) for intraprostatic tumor sextant localization, with histologic findings as reference standard.
  
  
  METHODS
  The local ethics committee on human research provided approval and a waiver of informed consent for the retrospective study. MR imaging, 3D MR spectroscopy, and 11C-choline PET/CT results were retrospectively reviewed in 26 men with biopsy-proved prostate cancer (mean age, 64 years; range, 51-75 years) who underwent radical prostatectomy. Cancer was identified as areas of nodular low signal intensity on T2-weighted MR images. At 3D MR spectroscopy, choline-plus-creatine-to-citrate and choline-to-creatine ratios were used to distinguish healthy from malignant voxels. At PET/CT, focal uptake was visually assessed, and maximum standardized uptake values (SUVs) were recorded. Agreement between 3D MR spectroscopic and PET/CT results was calculated, and ability of maximum SUV to help localize cancer was assessed with receiver operating characteristic analysis. Significant differences between positive and negative sextants with respect to mean maximum SUV were calculated with a paired t test.
  
  
  RESULTS
  Sensitivity, specificity, and accuracy were, respectively, 55%, 86%, and 67% at PET/CT; 54%, 75%, and 61% at MR imaging; and 81%, 67%, and 76% at 3D MR spectroscopy. The highest sensitivity was obtained when either 3D MR spectroscopic or MR imaging results were positive (88%) at the expense of specificity (53%), while the highest specificity was obtained when results with both techniques were positive (90%) at the expense of sensitivity (48%). Concordance between 3D MR spectroscopic and PET/CT findings was slight (kappa=0.139).
  
  
  CONCLUSIONS
  In localizing cancer within the prostate, comparable specificity was obtained with either 3D MR spectroscopy and MR imaging or PET/CT; however, PET/CT had lower sensitivity relative to 3D MR spectroscopy alone or combined with MR imaging.
authors.affiliation: Department of Clinical Medicine and Applied Biotechnology D. Campanacci, Diagnostic Imaging Section V. Bollini, Pathologic Anatomy Unit, Institute of Oncology F. Addarii, P.E.T. Center, Policlinico S. Orsola-Malpighi, University of Bologna, Italy.
authors.forename: Claudia
authors.initials: C
authors.lastname: Testa
authors.forename: Riccardo
authors.initials: R
authors.lastname: Schiavina
authors.forename: Raffaele
authors.initials: R
authors.lastname: Lodi
authors.forename: Eugenio
authors.initials: E
authors.lastname: Salizzoni
authors.forename: Barbara
authors.initials: B
authors.lastname: Corti
authors.forename: Mohsen
authors.initials: M
authors.lastname: Farsad
authors.forename: John
authors.initials: J
authors.lastname: Kurhanewicz
authors.forename: Fabio
authors.initials: F
authors.lastname: Manferrari
authors.forename: Eugenio
authors.initials: E
authors.lastname: Brunocilla
authors.forename: Caterina
authors.initials: C
authors.lastname: Tonon
authors.forename: Nino
authors.initials: N
authors.lastname: Monetti
authors.forename: Paolo
authors.initials: P
authors.lastname: Castellucci
authors.forename: Stefano
authors.initials: S
authors.lastname: Fanti
authors.forename: Manuela
authors.initials: M
authors.lastname: Coe
authors.forename: Walter F
authors.initials: WF
authors.lastname: Grigioni
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Martorana
authors.forename: Romeo
authors.initials: R
authors.lastname: Canini
authors.forename: Bruno
authors.initials: B
authors.lastname: Barbiroli
mesh_terms: D000328:Adult; D000368:Aged; D001706:Biopsy; D002250:Carbon Radioisotopes; D002794:Choline; D006801:Humans; D007091:Image Processing, Computer-Assisted; D021621:Imaging, Three-Dimensional; D008279:Magnetic Resonance Imaging; D009682:Magnetic Resonance Spectroscopy; D008297:Male; D008875:Middle Aged; D049268:Positron-Emission Tomography; D011468:Prostatectomy; D011471:Prostatic Neoplasms / Q000175:diagnosis* / Q000473:pathology / Q000601:surgery; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D014057:Tomography, X-Ray Computed
chemical_list: D002250:Carbon Radioisotopes; D002794:Choline