Assessment of Prostate Cancer With Dynamic Contrast-Enhanced Computed Tomography Using an En Bloc Approach

Abstract

The aim of this study was to assess the performance of dynamic contrast-enhanced computed tomography of the prostate in patients with biopsy-proven prostate cancer. A total of 46 male patients (median age, 65 years; range, 49-73 years) with biopsy-proven prostate cancer underwent an en bloc computed tomography perfusion (CTP) scan of the prostate before surgery. The perfusion parameters mean transit time (MTT), blood flow (BF), and blood volume (BV), as well as the microvessel density (MVD) of surgical specimens were determined. Differences in CTP parameters and MVD among postsurgical Gleason score (sGS) and postsurgical combined Gleason grade (sGG) groups were analyzed. Spearman correlation coefficients were determined between CTP parameters and presurgical biopsy-derived Gleason score (bGS), presurgical biopsy-derived combined Gleason grade (bGG), sGS, sGG, MVD, and pathological tumor stage. A linear regression analysis was carried out for exogenous variables BF, BV, MTT, bGS, and presurgical biopsy-derived combined Gleason grade and endogenous variables sGS, sGG, MVD, and T stage. A receiver operating characteristics analysis was performed to analyze the discriminating performance of CTP parameters and bGS between intermediate- and high-grade tumors. The mean perfusion parameters within the prostate tissue were as follows: BF, 39.1 ± 13.4 mL/100 mL min; BV, 4.9 ± 2.4 mL/100 mL; and MTT, 8.9 ± 3.7 seconds. The mean MVD of the tumor tissue was 144.3 ± 55.6/mm. Computed tomography perfusion parameters and MVD were significantly higher in patients with high-grade tumors compared with those with intermediate-grade tumors (P < 0.01 for BF, BV, and MVD). Only BV and MVD were significantly different among sGS and sGG groups. Moderate correlations were found between BF and sGS (0.38) and between BV and sGS (0.43). Linear relations of BV to sGS and to sGG were found. Blood volume (area under the curve, 0.86) was superior to bGS (area under the curve, 0.75) in discriminating high-grade from intermediate-grade tumors. Computed tomography perfusion parameters derived by en bloc perfusion of the prostate are higher in high-grade tumors compared with intermediate-grade tumors. Blood flow and BV correlate with the definitive Gleason score. Blood volume predicts high-grade tumors better than does the Gleason score of biopsy specimens. Further studies are needed to determine a potential role for CTP in prostate cancer patients.