AB069. Peripheral zone volume ratio (PZ-ratio) is relevant with biopsy results and can increase the accuracy of current diagnostic modality
Printed Abstract

AB069. Peripheral zone volume ratio (PZ-ratio) is relevant with biopsy results and can increase the accuracy of current diagnostic modality

Yifan Chang, Yinghao Sun, Rui Chen, Qingsong Yang, Xu Gao, Chuanliang Xu, Jianping Lu

Department of Urology, Changhai Hospital, Shanghai 200000, China


Background: To validate the diagnostic value of peripheral zone volume ratio (PZ-ratio) and its additional benefit in current diagnostic modality in detecting prostate cancer (PCa) or clinically significant PCa.

Methods: This retrospective study included 247 consecutive patients who underwent initial transrectal ultrasound-guided systematic prostate biopsy from April 2014 to November 2015. Univariate and multivariate regression analyses and linear correlation analyses were performed. Prostate volume was determined by semi-automatic contour in axial T2-weighted image (T2WI). Receiver operating characteristic (ROC) curve analyses and decision curve analyses were performed to evaluate the diagnostic efficacy of PZ-ratio and prediction models with PZ-ratio and MRI-findings.

Results: The median of PZ-ratio was 38.2% [interquartile range (IQR), 28.8–47.6%] in PCa patients, and 27.7% (IQR, 19.7–38.8%) in biopsy-negative patients (P=0.0001). PZ-ratio was inversely correlated with age (r = −0.36, P>0.0001). The area under the curve (AUC) of all patients and patients with PSA of 4–10 ng/mL were 0.672 and 0.676 in predicting PCa, respectively. Adding PZ-ratio and MRI findings to base model [age, prostate-specific antigen density (PSAD), free PSA percentage (%fPSA)] effectively increased AUC in all patients (0.871 vs. 0.812, P=0.0059), but not in patients with PSA 4–10 ng/mL (0.863 vs. 0.803, P=0.12). Similar results were observed in predicting significant PCa. In decision curve analyses, the new model significantly reduced the number of unnecessary biopsies while missing less significant cancers at a probability threshold of 25%.

Conclusions: PZ-ratio is a potential tool in predicting biopsy results. Adding PZ-ratio alone or in combination with MRI findings could increase diagnostic accuracy based on current diagnostic modality.

Keywords: Prostate cancer (PCa); multiparametric magnetic resonance imaging (multiparametric MRI); peripheral zone volume ratio; diagnosis


doi: 10.21037/tau.2018.AB069


Cite this article as: Chang Y, Sun Y, Chen R, Yang Q, Gao X, Xu C, Lu J. Peripheral zone volume ratio (PZ-ratio) is relevant with biopsy results and can increase the accuracy of current diagnostic modality. Transl Androl Urol 2018;7(Suppl 5):AB069. doi: 10.21037/tau.2018.AB069