Purpose: We conducted a trial in patients with prostate specific antigen (PSA) levels from 2 to 10 ng/ml to validate a newly developed nomogram that defines the optimal number of biopsy cores required for prostate cancer (PCa) detection based on patient age and total prostate volume (Vienna nomogram).
Materials and methods: A total of 502 patients underwent transrectal ultrasound guided prostate biopsy using the Vienna nomogram. These results were compared with those of a previous group of 1,051 patients who had standard octant biopsies followed by systematic repeat biopsies after 6 to 8 weeks if the initial biopsy result was negative for PCa.
Results: The overall PCa detection rate using the Vienna nomogram was 36.7% compared with 22% on first and 10% on repeat biopsy in the control group. The PCa detection rate using the Vienna nomogram was superior (p=0.002) to the octant biopsy technique, and comparable to a combination of first and repeat biopsy in the control group. Multivariate analysis of the Vienna nomogram showed that only PSA and the number of cores were independent predictors of PCa detection (chi-square = 49, p <0.001). Total prostate volume, transition zone volume and age were not independent predictors of PCa detection.
Conclusions: The Vienna nomogram offers an easy tool to select the optimal number of prostate biopsy cores based on patient age and total prostate volume in PSA range 2 to 10 ng/ml. Cancer detection is significantly improved (66.4%) compared to the control group. The bias factor of larger prostate volume is eliminated by using the Vienna nomogram. Moreover, the Vienna nomogram is advantageous not only in terms of the improved PCa detection rate but also economically makes systematic repeat biopsies unnecessary.