Perineural Invasion in Prostate Cancer Is More Frequently Detected by Multiparametric MRI Targeted Biopsy Compared With Standard Biopsy.

Multiparametric magnetic resonance imaging (MP-MRI) incorporates high-resolution imaging to aid in the detection of lesions suspicious for prostate cancer (PCa). MP-MRI and MRI/ultrasound (US) fusion-guided prostate biopsy has been shown to detect more clinically significant PCa. However, to date there have been no studies in fusion-guided biopsies evaluating the detection of perineural invasion. We assessed whether MRI/US fusion-guided prostate biopsies diagnosed more perineural invasion compared with standard techniques. We reviewed our prospectively maintained prostate biopsy database evaluating men who underwent MP-MRI and MRI/US fusion-guided prostate biopsy between January 2014 and June 2015. Patients underwent MP-MRI followed by 12-core standard biopsy and fusion-guided biopsies of MRI-identified lesions. Patients' clinical, radiologic, and pathologic findings were reviewed. A total of 114 patients underwent both 12-core standard biopsy and MRI/US fusion-guided prostate biopsy. The mean age and prebiopsy prostate-specific antigen of our patient cohort was 64.5 years and 10.7 ng/mL, respectively. Sixty-four of 114 (56%) patients were found to have PCa. Perineural invasion was identified in 19/64 (30%) patients. Of the patients with perineural invasion, 9 were diagnosed on the fusion biopsy only, 2 were diagnosed on standard biopsy only, and 8 were diagnosed on both standard and fusion biopsies. Perineural invasion was significantly associated with higher prostate-specific antigen and with a higher number of cores involved by cancer (P<0.05). Compared with standard biopsy, MRI/US fusion-guided prostate biopsy improves detection of perineural invasion in PCa. As perineural invasion has only been studied on standard biopsies to date, it is unclear whether this finding has the same clinical significance for MP-MRI targeted lesions.