Contrast-enhanced Transrectal Color Doppler Ultrasonography (TRCDUS) for assessment of angiogenesis in prostate cancer

Background: The clinical relevance of tumor angiogenesis has been investiga ted in several human tumors, including prostate carcinoma (PC). Previously, we found angiogenesis, measured as microvessel density (MVD), to be an ind ependent prognostic factor in PC. Therefore, we evaluated contrast-enhanced Transrectal Color Doppler Ultrasonography (TRCDUS) for assessment of angio genesis in PC. Materials and Methods: We investigated 15 patients with PC b efore radical prostatectomy (RP) and 3 control patients before radical cyst oprostatectomy. TRCDUS was performed using a microbubble-based ultrasound e nhancer Levovist (R) for identifying hypervascularized areas within the pro state. Computer-assisted quantification of color pixel intensity (PI) was u sed to evaluate objectively the hypervascularized areas; resistive index (R I) measurements were also obtained in these areas. After histopathological examination of the entire prostate gland for tumor confirmation, immunohist ochemical evaluation of MVD using a polyclonal antibody against factor VIII was performed as described by Weidner et al. (N Engl J Med 324: 1-8, 1991) . TRCDUS findings were correlated with the immunohistochemical data. Result s: All patients showed hypervascularized areas (range: 1-9) on contrast-enh anced TRCDUS. Hypervascularized areas showed a sensitivity of 50.8% and a s pecificity of 95.2% for detecting PC Analysis of TRCDUS data and immunohist ochemistry revealed a significant correlation between PI and MVD in PC spec imens, demonstrating a correlation coefficient of r(2) = 0.977 (p < 0.001). RI did not correlate with MVD. Conclusion. Contrast-enhanced TRCDUS showed a high specificity in identifying PC. PI correlated significantly with MVD . Therefore, quantification of color Doppler signals seems to be helpful fo r assessment of angiogenesis in PC.