The Effectiveness of 12 Core Biopsy Protocol according to Prostate-specific Antigen (PSA) Level and Prostate Volume

Purpose: The purpose of our study was to evaluate the effectiveness of the 12 core biopsy protocol in detecting prostate cancer by comparison with that of the 6 core biopsy according to the prostate-specific antigen (PSA) level and prostate volume. Materials and Methods: Between January 2000 and April 2005, transrectal ultrasound-guided prostate biopsies were performed on 1,100 men suspected of prostate cancer. Biopsy cores were taken from 12 sites, consisting of the routine sextant cores and 6 additional cores from the far lateral areas (lateral apex, mid-lobe and base). The protocol with cores taken from all 12 sites was defined as the ‘12 core biopsy protocol’ and the protocol with cores taken from the medial 6 sites only as the ‘6 core biopsy protocol'. The cancer detection rates of the two methods were analyzed according to the PSA level and prostate volume. Results: The cancer detection rates were 30.6 (337/1,100) and 25.7% (283/1,100) for the 12 and 6 core biopsy protocols, respectively. The patients were stratified into 3 groups according to their PSA level, and another 3 groups according to their prostate volume. The detection rates of the 12 core biopsy protocol were higher in all groups. The patients were stratified into a further 9 groups according to both their PSA level and prostate volume. The 12 core biopsy protocol proved to be more effective than the 6 core biopsy protocol in most groups, with the exception of groups with a relatively low PSA and large prostate volume and those with a relatively high PSA and small prostate volume. Furthermore, when stratified by the PSA density (PSAD), the 12 core biopsy protocol showed higher detection rates in patients with levels between 0.05 and 0.3. Conclusions: These results show that the detection rate of the 12 core biopsy protocol is higher in most groups, with the exception of groups with an extremely low or high PSAD, which suggests the PSAD may be a useful factor in determining the number of cores required for a prostate biopsy. (Korean J Urol 2006;47:1166-1171) 󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏