Evaluating Prostate Cancer Using Fractional Tissue Composition of Radical Prostatectomy Specimens and Pre-Operative Diffusional Kurtosis Magnetic Resonance Imaging.

Evaluating tissue heterogeneity using non-invasive imaging could potentially improve prostate cancer assessment and treatment.

20 patients with intermediate/high-risk prostate cancer underwent diffusion kurtosis imaging, including calculation of apparent diffusion (Dapp) and kurtosis (Kapp), prior to radical prostatectomy. Whole-mount tissue composition was quantified into: cellularity, luminal space, and fibromuscular stroma. Peripheral zone tumors were subdivided according to Gleason score.

Peripheral zone tumors had increased cellularity (p<0.0001), decreased fibromuscular stroma (p<0.05) and decreased luminal space (p<0.0001). Gleason score ≥4+3 tumors had significantly increased cellularity and decreased fibromuscular stroma compared to Gleason score ≤3+4 (p<0.05). In tumors, there was a significant positive correlation between median Kapp and cellularity (ρ = 0.50; p<0.05), and a negative correlation with fibromuscular stroma (ρ = -0.45; p<0.05). In normal tissue, median Dapp had a significant positive correlation with luminal space (ρ = 0.65; p<0.05) and a negative correlation with cellularity (ρ = -0.49; p<0.05). Median Kapp and Dapp varied significantly between tumor and normal tissue (p<0.0001), but only median Kapp was significantly different between Gleason score ≥4+3 and ≤3+4 (p<0.05).

Peripheral zone tumors have increased cellular heterogeneity which is reflected in mean Kapp, while normal prostate has a more homogeneous luminal space and cellularity better represented by Dapp.

PloS one. 2016 Jul 28*** epublish ***

Edward M Lawrence, Anne Y Warren, Andrew N Priest, Tristan Barrett, Debra A Goldman, Andrew B Gill, Vincent J Gnanapragasam, Evis Sala, Ferdia A Gallagher

Department of Radiology, University of Cambridge, Addenbrooke's hospital, Cambridge, United Kingdom., Department of Histopathology, University of Cambridge, Addenbrooke's hospital, Cambridge, United Kingdom., Department of Radiology, University of Cambridge, Addenbrooke's hospital, Cambridge, United Kingdom., Department of Radiology, University of Cambridge, Addenbrooke's hospital, Cambridge, United Kingdom., Department of Epidemiology & Biostatistics, Memorial Sloan Kettering Cancer Center, 1275 York Ave, New York, NY, United States of America., Department of Radiology, University of Cambridge, Addenbrooke's hospital, Cambridge, United Kingdom., Department of Urology, University of Cambridge, Addenbrooke's hospital, Cambridge, United Kingdom., Department of Radiology, Memorial Sloan Kettering Cancer Center, 1275 York Ave, New York, NY, United States of America., Department of Radiology, University of Cambridge, Addenbrooke's hospital, Cambridge, United Kingdom.