What is the ideal number of biopsy cores per lesion in targeted prostate biopsy?

Background: The number of cores to be obtained in targeted biopsy (TB) is important. This study aimed to evaluate the TB outcomes in suspicious prostate lesions classified according to the Prostate Imaging Reporting and Data System (PI-RADS) and to determine the ideal number of biopsy cores per lesion. Methods: This retrospective study included patients who underwent multiparametric magnetic resonance imagingeguided fusion prostate biopsy owing to increased serum prostate-specific antigen (PSA) levels and suspicious digital rectal examination outcomes in our institute. Patients with PI-RADS <3 lesions, PSA levels >10 ng/ml, and a prior diagnosis of prostate cancer (PCa) (active surveillance) were excluded from the study. The number of biopsy cores to be obtained from each lesion was determined by the clinician. Results: The study included a total of 418 patients and 684 lesions. Among PI-RADS 3 lesions, clinically significant PCa (sPCa) detection rate was similar in the lesions from which 2 and 3 cores were obtained (9.1% and 10.0%, respectively), whereas it was relatively higher in the lesions from which 4 biopsy cores were obtained (18.5%). Among PI-RADS 4 lesions, sPCa detection rate was similar in the lesions from which 3 and 4 cores were obtained (35.6% and 32.3%, respectively), whereas it was relatively lower in the lesions from which 2 biopsy cores were obtained (17.9%). Among PI-RADS 5 lesions, however, sPCa detection rate was similar in the lesions from which 2, 3, or 4 cores were obtained (47.6%, 46.0%, 48.9%, respectively). Conclusion: The results indicated that the ideal number of cores to be obtained from each suspicious lesion in TB depends on the characteristics of the lesions. Accordingly, while obtaining 2-3 biopsy cores could be adequate in PI-RADS 4 and 5 lesions, which have a serious risk of cancer, a minimum of 4 biopsy cores should be obtained from PI-RADS 3 lesions to ensure accurate histopathological results. Clinical trial number (ClinicalTrials.gov)NCT03936296. (c) 2020 Asian Pacific Prostate Society. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).