Correlation of power Doppler with microvessel density in assessing prostate needle biopsy

To correlate hypervascular power Doppler ultrasonography with the histological evaluation of microvasculature in the prostate using trans-rectal ultrasound (TRUS)-guided needle biopsy.

Ninety-six patients with a lower urinary tract symptoms (LUTS) and prostate specific antigen (PSA) value more than 4 ng/ml were evaluated using power Doppler ultrasonography before biopsy. The vascularity of the peripheral zone was graded on a scale of PZ0 to PZ2. Core needle biopsies were immunostained with CD31(DAKO) and counting was performed manually on separate high power fields (HPF; x 400) in areas containing the highest number of vessels.

There was a significant correlation between the grading system used for power Doppler and the microvessel density (MVD; PZ0 28.61 +/- 8.97,PZ1 36.00 +/- 12.11 & PZ2 64.008 +/- 15.86; p < 0.001). There was also a significant difference in MVD between benign, malignant and tissue cores with atypia and prostatic intra-epithelial neoplasia (PIN; p < 0.001 and p < 0.018 respectively). There was a significant correlation between malignant tissue having a higher Gleason score and increased MVD (p < 0.001) Furthermore, cancer biopsies having a high flow PZ2 are nearly twice as likely (63.2%) to have a Gleason score of 7 or more when compared those having a Gleason score of less than 7 (36.8%).

The grading system of assessing the power Doppler flow signals appears to be of value as an indicator of MVD. It also correlates with a higher Gleason score and this may reflect the clinical outcome in prostate cancer. It deserves further study and evaluation as a prognostic indicator.