Prostate cancer: correlation of intravoxel incoherent motion MR parameters with Gleason score.
PURPOSE
To evaluate the potential of intravoxel incoherent motion (IVIM) imaging to predict histological prognostic parameters by investigating whether IVIM parameters correlate with Gleason score.


MATERIALS AND METHODS
The institutional review board approved this retrospective study, and informed consent was waived. A total of 41 patients with histologically proven prostate cancer who underwent prostate MRI using a 3T MRI machine were included. For eight diffusion-weighted imaging b-values (0, 10, 20, 50, 100, 200, 500, and 800s/mm(2)), a spin-echo echo-planar imaging sequence was performed. D, f, D(⁎), and ADCfit values were compared among three groups of patients with prostate cancer: Gleason score 6 (n=9), 7 (n=16), or 8 or higher (n=16). Receiver operating characteristic (ROC) curves were generated for D, f, D(⁎), and ADCfit to assess the ability of each parameter to distinguish cancers with low Gleason scores from cancers with intermediate or high Gleason scores.


RESULTS
Pearson's coefficient analysis revealed significant negative correlations between Gleason score and ADCfit (r=-0.490, P=.001) and Gleason score and D values (r=-0.514, P=.001). Gleason score was poorly correlated with f (r=0.168, P=.292) and D(⁎) values (r=-0.108, P=.500). The ADCfit and D values of prostate cancers with Gleason scores 7 or ≥8 were significantly lower than values for prostate cancers with Gleason score 6 (P<.05). ROC curves were constructed to assess the ability of IVIM parameters to discriminate prostate cancers with Gleason score 6 from cancers with Gleason scores 7 or ≥8. Areas under the curve were 0.671 to 0.974. ADCfit and D yielded the highest Az value (0.960-0.956), whereas f yielded the lowest Az value (0.633).


CONCLUSIONS
The pure molecular diffusion parameter, D, was the IVIM parameter that best discriminated prostate cancers with low Gleason scores from prostate cancers with intermediate or high Gleason scores.
['Yang|Dal Mo|DM|', 'Kim|Hyun Cheol|HC|', 'Kim|Sang Won|SW|', 'Jahng|Geon-Ho|GH|', 'Won|Kyu Yeoun|KY|', 'Lim|Sung Jig|SJ|', 'Oh|Jang-Hoon|JH|']
D000368:Aged D000369:Aged, 80 and over D019540:Area Under Curve D038524:Diffusion Magnetic Resonance Imaging D017352:Echo-Planar Imaging D006801:Humans D007090:Image Interpretation, Computer-Assisted D008297:Male D008875:Middle Aged D009038:Motion D060787:Neoplasm Grading D011467:Prostate D011471:Prostatic Neoplasms D012372:ROC Curve D012189:Retrospective Studies
Prostate Prostate cancer Diffusion-weighted imaging Incoherent intravoxel motion MRI Magnetic resonance imaging