Ultrasound analysis of seminal vesicles in prostate cancer invasion: monocentric experience of an extended prostate biopsy scheme.

Abstract

At present, uniformity does not exist with regard to the indication criteria of seminal vesicle (SV) biopsies. The aim of this study was to define the ultrasonographic (US) patterns observed in SV invaded by prostate cancer (PCa), and propose an extended prostate biopsy protocol when SV invasion (SVI) is suspected. We reviewed 1.252 patients who underwent an initial transrectal ultrasound-guided prostate biopsy for suspicious PCa. We performed a 14-core biopsy scheme, as first intention, including 1 SV sample on each side when SVI is suspected: a nodule at the base of prostate (determined by digital rectal examination or US) and/or an US pattern that suggests a SVI. US patterns of SVs were classified as abnormal by a variation of the body anterior-posterior diameter, asymmetry of the volume, parietal thickness, distance between the SVs and the rectal surface, and altered echogenicity of SVs and the base of the prostate. Of the 137 biopsies performed in SVs, the SVI by PCa was diagnosed in 66.5% of candidate patients. The overall prevalence of SVI was 28.5%. No significant difference was noted between the patients with SVI and without SVI, when comparing age, prostate volume, and total core length, except for preoperative PSA serum levels. The sensitivity of any abnormal finding on transrectal ultrasound for the presence of SVI by PCa is 90.8%, whereas the specificity is 96%. We believe that an extended prostate biopsy protocol to provide the possibility of taking one biopsy core of each SV when SVI is suspected should be considered a complementary procedure for PCa staging.