Utility of computed diffusion-weighted MRI for predicting aggressiveness of prostate cancer.
To investigate the value of computed (c) diffusion-weighted imaging (DWI) in assessing prostate cancer aggressiveness.



Fifty-five patients with peripheral zone prostate cancer who underwent prebiopsy 1.5T magnetic resonance imaging (including native DWI at b-values of 0 and 1000 s/mm2) were included. cDWI signal intensities of peripheral zone prostate cancer and nonmalignant prostate tissue were measured. Association between changes in monoexponentially calculated cDWI signals according to different b-values and primary Gleason grades were assessed.



The cDWI signal intensity of prostate cancer was lower at b = 0 s/mm2and higher at b = 1000 s/mm2compared to nonmalignant prostate tissue. The b-value at which the signal intensities of prostate cancer and nonmalignant prostate tissue were equal was defined as the "iso-b-value." On multivariate analysis, only the iso-b-value was a significant predictor of primary Gleason grade 4/5 cancer (P = 0.001). The area under the curve (AUC) of the iso-b-value for diagnosing primary Gleason grade 4/5 cancer was 0.94, and significantly higher than that of the tumor apparent diffusion coefficient (ADC) value with an AUC of 0.68 (P < 0.001).



cDWI with iso-b-value-based semiquantitative analysis was found to be useful for predicting the aggressiveness of prostate cancer and may potentially outperform tumor ADC measurements in this setting.



3 Technical Efficacy: Stage 2 J. MAGN. RESON. IMAGING 2017;46:490-496.
Urology, Tokyo Medical and Dental University Graduate School, Tokyo, Japan.
Yuma
Y
Waseda
Urology, Tokyo Medical and Dental University Graduate School, Tokyo, Japan.
Soichiro
S
Yoshida
Biomedical Engineering, Tokai University School of Engineering, Kanagawa, Japan.
Taro
T
Takahara
Department of Radiology, University Medical Center Groningen, Groningen, Netherlands.
Thomas Christian
TC
Kwee
Urology, Tokyo Medical and Dental University Graduate School, Tokyo, Japan.
Yoh
Y
Matsuoka
Urology, Tokyo Medical and Dental University Graduate School, Tokyo, Japan.
Kazutaka
K
Saito
Urology, Tokyo Medical and Dental University Graduate School, Tokyo, Japan.
Kazunori
K
Kihara
Urology, Tokyo Medical and Dental University Graduate School, Tokyo, Japan.
Yasuhisa
Y
Fujii
D000368:Aged; D019540:Area Under Curve; D038524:Diffusion Magnetic Resonance Imaging; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D060787:Neoplasm Grading; D009361:Neoplasm Invasiveness; D017430:Prostate-Specific Antigen / Q000097:blood; D011468:Prostatectomy; D011471:Prostatic Neoplasms / Q000000981:diagnostic imaging*; D012372:ROC Curve; D015203:Reproducibility of Results; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D012815:Signal Processing, Computer-Assisted
D017430:Prostate-Specific Antigen
Gleason grading; biomarkers; diffusion magnetic resonance imaging; multimodal imaging; prostatic neoplasms