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

Abstract

OBJECTIVES The aim of this study was to assess the performance of dynamic contrastenhanced computed tomography of the prostate in patients with biopsy-proven prostate cancer. MA-TERIAL AND METHODS 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. RESULTS 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.

Assessment of prostate cancer with integrated CT-perfusion using a sector-wise approach

“…They found higher BF and BV in high-grade PCa (Gleason score >7) rather than in intermediate-(Gleason score=7) and low-grade (Gleason score <7) tumors. Similar results were found recently by Huellner et al [11] using an en-bloc approach. In our study, in which we used a sector-wise approach, we have found correlation between Gleason score and BV but not with BF.…”

“…In our study, in which we used a sector-wise approach, we have found correlation between Gleason score and BV but not with BF. BV is consistently reported to be associated with PCA grading and/or vascularity in different study populations and in CTP studies using different technical approaches (9,11,22,26 and present study). These results raise the question for a potential role of BV for non-invasive PCa characterization via determining tumor aggressiveness.…”

“…A recent en-bloc approach has shown that patients with high-grade and intermediate-grade PCa can be more precisely differentiated with CTP rather than with biopsy. [11] However, a more comprehensive approach is desired that could potentially locate and characterize the tumor within the prostate. Thus we investigated CTP using a sector-wise approach.…”

“…On the other hand, it might also be more appropriate to use than more coarse methods, which despite being fast processing and user-friendly, might not appreciate smaller lesions well enough. [9,11] Our study has several limitations. First, the retrospective matching of CT slices and histopathologic sections is prone to misregistration to some extent.…”

“…[9,10] Recently, CTP using an en-bloc approach has demonstrated that perfusion parameters may predict the aggressiveness of PCa more precisely than histopathological findings of biopsy specimens. [11] However, any correlation between perfusion parameters and Gleason score could not be demonstrated, which is usually present between Gleason score, and MRI perfusion findings. [12,13] The aim of our study was to investigate the relationship between CTP parameters and histopathological features of PCa tissue using a comprehensive, sector-wise approach.…”