Combination of PI-RADS score and PSA density predicts biopsy outcome in biopsy naïve patients.

To assess the value of the Prostate Imaging Reporting and Data System (PI-RADS) scoring system, for prostate multi-parametric magnetic resonance imaging (mpMRI) to detect prostate cancer, and classical parameters, such as prostate specific antigen (PSA), prostate volume and PSA density, for predicting biopsy outcome in biopsy naïve patients who have suspected prostate cancer (PCa).

Patients who underwent mpMRI at our hospital, and who had their first prostate biopsy between July 2010 and April 2014, were analysed retrospectively. The prostate biopsies were performed transperineally under transrectal ultrasound guidance. Fourteen cores were biopsied as a systemic biopsy in all patients. Two cognitive fusion-targeted biopsy cores were added for each lesion in patients who had suspicious or equivocal lesions on mpMRI. The PI-RADS scoring system ver. 2.0 (PI-RADS v2) was used to describe the MRI findings. Univariate and multivariate analyses were performed to determine significant predictors of PCa and clinically significant PCa.

In total, 288 patients were analysed. Median patient age, PSA, prostate volume and PSA density were 69, 7.5 ng/mL, 28.7 cm3 and 0.26 ng/mL/cm3, respectively. The biopsy results were benign, clinically insignificant and clinically significant PCa in 129 (45%), 18 (6%) and 141 (49%) patients, respectively. The multivariate analysis revealed that PI-RADS v2 score and PSA density were independent predictors for PCa and clinically significant PCa. When PI-RADS v2 score and PSA density were combined, PI-RADS v2 score > 4 and PSA density > 0.15, or PI-RADS v2 score 3 and PSA density > 0.30, was associated with the highest clinically significant PCa detection rates (76-97%) on the first biopsy. Of the patients in this group with negative biopsy results, 22% were subsequently diagnosed as PCa. In contrast, PI-RADS v2 score < 3 and PSA density < 0.15 yielded no clinically significant PCa and no additional detection of PCa on further biopsies.

A combination of PI-RADS v2 score and PSA density can help in the decision-making process before prostate biopsy and the follow-up strategy in biopsy naïve patients. Patients with PI-RADS v2 score < 3 and PSA density < 0.15 may avoid unnecessary biopsies. This article is protected by copyright. All rights reserved.

BJU international. 2016 Mar 02 [Epub ahead of print]

Satoshi Washino, Tomohisa Okochi, Kimitoshi Saito, Tsuzumi Konishi, Masaru Hirai, Yutaka Kobayashi, Tomoaki Miyagawa

The department of radiology, Jichi Medical University Saitama Medical Center, Amanuma-cho, Omiya-ku, 330-8503 1-847, Saitama, Japan., The department of radiology, Jichi Medical University Saitama Medical Center, Amanuma-cho, Omiya-ku, 330-8503 1-847, Saitama, Japan., The department of radiology, Jichi Medical University Saitama Medical Center, Amanuma-cho, Omiya-ku, 330-8503 1-847, Saitama, Japan., The department of radiology, Jichi Medical University Saitama Medical Center, Amanuma-cho, Omiya-ku, 330-8503 1-847, Saitama, Japan., The department of radiology, Jichi Medical University Saitama Medical Center, Amanuma-cho, Omiya-ku, 330-8503 1-847, Saitama, Japan., The department of radiology, Jichi Medical University Saitama Medical Center, Amanuma-cho, Omiya-ku, 330-8503 1-847, Saitama, Japan., The department of radiology, Jichi Medical University Saitama Medical Center, Amanuma-cho, Omiya-ku, 330-8503 1-847, Saitama, Japan.