Repeat transrectal ultrasound biopsies with additional targeted cores according to results of functional prostate MRI detects high-risk prostate cancer in patients with previous negative biopsy and increased PSA - a pilot study.

BACKGROUND/AIM Patients with previous negative transrectal ultrasound-guided biopsy (TRUS-GB) and persistently increased prostate-specific antigen (PSA) value represent a great diagnostic problem. Magnetic resonance imaging (MRI)-guided biopsy demonstrates high prostate cancer detection rates in these patients if functional MRI is suspicious for prostate cancer. However, MRI-guided biopsy is not commonly available and features considerable technical requirements. This was a pilot study to investigate if a standard repeat TRUS-GB, with additional targeted cores to suspicious lesions on functional MRI, can achieve similar detection rates as compared to MRI-guided biopsy. PATIENTS AND METHODS 3 Tesla functional MRI was performed in 58 patients with ≥1 previous negative biopsy, persistently increased PSA ≥4 ng/ml and unsuspicious digital rectal examination. Suspicious lesions were marked on a localization map to enable their finding on TRUS. Random TRUS-GB with additional targeted cores according to the functional MRI findings were performed in patients with ≥1 suspicious lesion. RESULTS In 37.9% (22/58), functional MRI demonstrated suspicious findings. Out of these 22 patients, 16 underwent TRUS-GB with additional targeted cores. Prostate cancer was diagnosed in 68.8% (11/16). Eight out of these 11 patients subsequently underwent radical prostatectomy and all tumors fulfilled criteria for high-risk prostate cancer. With a median follow-up of 49.1 weeks neither significant PSA increase nor prostate cancer was detected in patients with normal functional MRI findings. CONCLUSION Our approach enables excellent detection rates of clinically significant prostate cancer in patients with ≥1 previous negative biopsy and persistently increased PSA levels. Due to the current disadvantages of MRI-guided biopsy, our approach therefore represents an excellent alternative to MRI-guided biopsy.