What is the ideal core number for ultrasound-guided prostate biopsy?

We evaluated the utility of 10-, 12-, and 16-core prostate biopsies for detecting prostate cancer (PCa) and correlated the results with prostate-specific antigen (PSA) levels, prostate volumes, Gleason scores, and detection rates of high-grade prostatic intraepithelial neoplasia (HGPIN) and atypical small acinar proliferation (ASAP).

A prospective controlled study was conducted in 354 consecutive patients with various indications for prostate biopsy. Sixteen-core biopsy specimens were obtained from 351 patients. The first 10-core biopsy specimens were obtained bilaterally from the base, middle third, apex, medial, and latero-lateral regions. Afterward, six additional punctures were performed bilaterally in the areas more lateral to the base, middle third, and apex regions, yielding a total of 16-core biopsy specimens. The detection rate of carcinoma in the initial 10-core specimens was compared with that in the 12- and 16-core specimens.

No significant differences in the cancer detection rate were found between the three biopsy protocols. PCa was found in 102 patients (29.06%) using the 10-core protocol, in 99 patients (28.21%) using the 12-core protocol, and in 107 patients (30.48%) using the 16-core protocol (p=0.798). The 10-, 12-, and 16-core protocols were compared with stratified PSA levels, stratified prostate volumes, Gleason scores, and detection rates of HGPIN and ASAP; no significant differences were found.

Cancer positivity with the 10-core protocol was not significantly different from that with the 12- and 16-core protocols, which indicates that the 10-core protocol is acceptable for performing a first biopsy.