Can Power Doppler enhanced transrectal ultrasound guided biopsy improve prostate cancer detection on first and repeat prostate biopsy?

Abstract

Objective: To determine the utility of Power Doppler enhanced transrectal ultrasound (PD-TRUS) and its guided prostate biopsies in men with prostate specific antigen (PSA) levels between 2.5 and 10 ng/ml and to evaluate its impact on prostate cancer (PCa) detection in men undergoing first and repeat biopsies.

Methods: A total of 136 consecutive referred men with serum total PSA (Abbott Laboratories, Abbott Park, IL, USA) levels between 2.5 and 10 ng/ml (mean age 64 +/- 9 years, range 45-82) and a normal digital rectal examination were included. 101 underwent a first biopsy whereas 35 had repeat biopsy. Gray-scale transrectal ultrasound (TRUS), and PD-TRUS (B&K Medical, Denmark) were performed in lithotomy position before and during the biopsy procedure. Vascularity accumulation and perfusion characteristics were recorded and graded as normal or abnormal in the peripheral zone of the prostate. A Vienna-nomogram based biopsy regime was performed in all patients on first biopsy and a special biopsy regime on repeat biopsy plus additional biopsies from abnormal sites on PD-TRUS.

Results: Overall PCa detection rate was 34.7% and 25.7% and abnormal accumulation on PD-TRUS was identified in 42.3% and 48.6% on first and repeat biopsy, respectively. The PCa detection rate, on first and repeat biopsy in patients with and without PD-TRUS accumulation were 67.4% versus 10.3% (p < 0.001) and 47.05% versus 5.6% (p = 0.0049), respectively. PD-TRUS directed biopsies were positive in 5.7% and 11.1% on first and repeat biopsy whereas PCa detection using the routine prostate biopsy regime was 94.3% and 88.9% on first and repeat biopsy. The sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of PD-TRUS signal alone for PCa detection on first biopsy was 82.8%, 78.8%, 87.9% and 89.7%, respectively, and 88.8%, 68.0%, 47.0% and 94.4% on repeat biopsy, respectively. In comparison, the results PD-TRUS guided biopsies were 53.8%, 59.1%, 16.7%, and 89.5%, on first biopsy, respectively, and 20.0%, 13.3%, 23.5%, 11.1% on repeat biopsy, respectively.

Conclusion: Negative PD-TRUS signal is able to exclude most of the patients without PCa in the PSA range of 2.5-10 ng/ml. As an additional tool at TRUS biopsy PD-TRUS has a high negative predictive value and may help to reduce the number of unnecessary biopsies.