title: Prostate Cancer: Diffusion-weighted MR Imaging for Detection and Assessment of Aggressiveness-Comparison between Conventional and Kurtosis Models.
abstract: Purpose To compare standard diffusion-weighted (DW) imaging and diffusion kurtosis (DK) imaging for prostate cancer (PC) detection and characterization in a large patient cohort, with attention to the potential added value of DK imaging. Materials and Methods This retrospective institutional review board-approved study received a waiver of informed consent. Two hundred eighty-five patients with PC underwent 3.0-T phased-array coil prostate magnetic resonance (MR) imaging, including a DK imaging sequence (b values 0, 500, 1000, 1500, and 2000 sec/mm2) before prostatectomy. Maps of apparent diffusion coefficient (ADC) and diffusional kurtosis (K) were derived by using maximal b values of 1000 and 2000 sec/mm2, respectively. Mean ADC and K were obtained from volumes of interest (VOIs) placed on each patient's dominant tumor and benign prostate tissue. Metrics were compared between benign and malignant tissue, between Gleason score (GS) ≤ 3 + 3 and GS ≥ 3 + 4 tumors, and between GS ≤ 3 + 4 and GS ≥ 4 + 3 tumors by using paired t tests, analysis of variance, receiver operating characteristic (ROC) analysis, and exact tests. Results ADC and K showed significant differences for benign versus tumor tissues, GS ≤ 3 + 3 versus GS ≥ 3 + 4 tumors, and GS ≤ 3 + 4 versus GS ≥ 4 + 3 tumors (P < .001 for all). ADC and K were highly correlated (r = -0.82; P < .001). Area under the ROC curve was significantly higher (P = .002) for ADC (0.921) than for K (0.902) for benign versus malignant tissue but was similar for GS ≤ 3 + 3 versus GS ≥ 3 + 4 tumors (0.715-0.744) and GS ≤ 3 + 4 versus GS ≥ 4 + 3 tumors (0.694-0.720) (P > .15). ADC and K were concordant for these various outcomes in 80.0%-88.6% of patients; among patients with discordant results, ADC showed better performance than K for GS ≤ 3 + 4 versus GS ≥ 4 + 3 tumors (P = .016) and was similar to K for other outcomes (P > .136). Conclusion ADC and K were highly correlated, had similar diagnostic performance, and were concordant for the various outcomes in the large majority of cases. These observations did not show a clear added value of DK imaging compared with standard DW imaging for clinical PC evaluation.©RSNA, 2017 Online supplemental material is available for this article.
authors.affiliation: From the Department of Radiology (T.T., V.P., J.S.B., A.B.R.), Department of Pathology (J.L.), and Division of Urologic Oncology, Department of Urology (S.S.T., A.B.R.), NYU Langone Medical Center, 550 First Ave, New York, NY 10016.
authors.forename: Tsutomu
authors.initials: T
authors.lastname: Tamada
authors.affiliation: From the Department of Radiology (T.T., V.P., J.S.B., A.B.R.), Department of Pathology (J.L.), and Division of Urologic Oncology, Department of Urology (S.S.T., A.B.R.), NYU Langone Medical Center, 550 First Ave, New York, NY 10016.
authors.forename: Vinay
authors.initials: V
authors.lastname: Prabhu
authors.affiliation: From the Department of Radiology (T.T., V.P., J.S.B., A.B.R.), Department of Pathology (J.L.), and Division of Urologic Oncology, Department of Urology (S.S.T., A.B.R.), NYU Langone Medical Center, 550 First Ave, New York, NY 10016.
authors.forename: Jianhong
authors.initials: J
authors.lastname: Li
authors.affiliation: From the Department of Radiology (T.T., V.P., J.S.B., A.B.R.), Department of Pathology (J.L.), and Division of Urologic Oncology, Department of Urology (S.S.T., A.B.R.), NYU Langone Medical Center, 550 First Ave, New York, NY 10016.
authors.forename: James S
authors.initials: JS
authors.lastname: Babb
authors.affiliation: From the Department of Radiology (T.T., V.P., J.S.B., A.B.R.), Department of Pathology (J.L.), and Division of Urologic Oncology, Department of Urology (S.S.T., A.B.R.), NYU Langone Medical Center, 550 First Ave, New York, NY 10016.
authors.forename: Samir S
authors.initials: SS
authors.lastname: Taneja
authors.affiliation: From the Department of Radiology (T.T., V.P., J.S.B., A.B.R.), Department of Pathology (J.L.), and Division of Urologic Oncology, Department of Urology (S.S.T., A.B.R.), NYU Langone Medical Center, 550 First Ave, New York, NY 10016.
authors.forename: Andrew B
authors.initials: AB
authors.lastname: Rosenkrantz
mesh_terms: D000230:Adenocarcinoma / Q000000981:diagnostic imaging* / Q000473:pathology / Q000601:surgery; D000368:Aged; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods*; D006801:Humans; D008297:Male; D008875:Middle Aged; D011468:Prostatectomy; D011471:Prostatic Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology / Q000601:surgery; D012189:Retrospective Studies