title: Transition zone prostate cancer: revisiting the role of multiparametric MRI at 3 T.
abstract: OBJECTIVE. The purpose of this study was to retrospectively evaluate the impact of multiparametric prostate MRI, including diffusion-weighted imaging (DWI) performed using different b values as well as dynamic contrast-enhanced MRI (DCE-MRI) on the accuracy, sensitivity, and specificity for transition zone (TZ) tumor detection and localization. MATERIALS AND METHODS. We included 106 prostate cancer patients (mean age [± SD], 62 ± 7 years) who underwent 3-T MRI with a pelvic phased-array coil before radical prostatectomy. Three radiologists independently reviewed cases to record the likelihood of tumor in each of six TZ regions. Scores were initially assigned using T2-weighted imaging alone, reassigned after integration of DWI at b = 1000 s/mm(2) and corresponding apparent diffusion coefficient (ADC) maps, reassigned again after integration of DWI at b = 2000 s/mm(2), and reassigned a final time after integration of DCE-MRI. Generalized estimating equations based on binary logistic regression were used to compare sessions for TZ tumor detection, using prostatectomy findings as reference standard. RESULTS. Of the TZ sextants, 9.7% (62/636) contained tumor. All readers had higher sensitivity for T2-weighted imaging integrated with DWI at b = 1000 s/mm(2) and ADC compared with T2-weighted imaging alone (reader 1, 54.8% vs 33.9%; reader 2, 53.2% vs 22.6%; and reader 3, 50.0% vs 19.4% [p ≤ 0.002]); two readers had further increased sensitivity also incorporating b = 2000 s/mm(2) (reader 1, 74.2% and reader 2, 62.9%; p ≤ 0.011), and one reader had further increased sensitivity also incorporating both b = 2000 s/mm(2) and DCE-MRI (reader 3, 61.3%, p = 0.013). DCE-MRI otherwise did not improve sensitivity (p ≥ 0.054). Other measures were similar across the four sessions (reader 1, specificity 97.4-98.3% and accuracy 91.2-95.9%; reader 2, specificity 95.8-98.4% and accuracy 91.0-92.6%; reader 3, specificity 90.9-96.7% and accuracy 88.1-89.2%). CONCLUSION. DWI assists TZ tumor detection through higher sensitivity, particularly when using a very high b value; DCE-MRI lacks further additional benefit.
authors.affiliation: 1 Department of Radiology, Center for Biomedical Imaging, NYU School of Medicine, NYU Langone Medical Center, 660 First Ave, 3rd Fl, New York, NY 10016.
authors.forename: Andrew B
authors.initials: AB
authors.lastname: Rosenkrantz
authors.forename: Sooah
authors.initials: S
authors.lastname: Kim
authors.forename: Naomi
authors.initials: N
authors.lastname: Campbell
authors.forename: Byron
authors.initials: B
authors.lastname: Gaing
authors.forename: Fang-Ming
authors.initials: FM
authors.lastname: Deng
authors.forename: Samir S
authors.initials: SS
authors.lastname: Taneja
mesh_terms: D000368:Aged; D038524:Diffusion Magnetic Resonance Imaging; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D011471:Prostatic Neoplasms / Q000473:pathology*; D015203:Reproducibility of Results; D012189:Retrospective Studies; D012680:Sensitivity and Specificity
keywords: MRI; diffusion-weighted imaging; dynamic contrast-enhanced imaging; prostate cancer; transition zone