The value of magnetic resonance imaging-ultrasound fusion targeted biopsies for clinical decision-making among patients with previously negative transrectal ultrasound biopsy and persistent prostate-specific antigen elevation.

Abstract

Targeted biopsy approaches have been shown to increase the detection of clinically significant prostate cancer (csPCa) within index prostate lesions. We report our initial experience with magnetic resonance imaging-ultrasound fusion biopsies (MRI-TB) in a population of men who had a previously negative transrectal ultrasound (TRUS) biopsy, persistent prostate-specific antigen (PSA) elevation, and ongoing suspicion of PCa. Patients were followed prospectively to assess for changes in clinical management following targeted biopsy. We prospectively followed the first 122 patients undergoing MRI-TB at our institution. All men had clinical suspicion of PCa, prior negative TRUS biopsies, and persistent PSA elevation. A total of 177 index lesions were identified on multiparametric MRI and reviewed using the Prostate Imaging Reporting and Data System (PI-RADS) v2 scoring system. Lesions classified as PI-RADS ≥3 received targeted biopsy. Biopsy-naive patients and those on active surveillance were excluded. The primary outcome was detection rate of csPCa, defined as International Society of Urological Pathology (ISUP) Grade Group (GG) ≥2. Multivariate analysis was used to determine predictors of csPCa on fusion biopsy. Prior to fusion biopsy, patients had a mean of 17.9±8.6 negative core biopsies per patient and a median PSA of 9.5 (standard deviation [SD] 6.2) ng/nl. MRI-TB resulted in diagnosis of csPCa in 42/122 (34.4%) patients. Clinically significant PCa was found in eight (13.1%), 14 (21.9%), and 25 (48.1%) of PI-RADS 3, 4, and 5 lesions, respectively. The location of csPCa was within the peripheral zone (55.3%), transitional zone (40.4%), and central zone (8.5%). Clinical outcomes of patients with newly diagnosed csPCa show 4.8%, 57.1%, and 38.1% receiving active surveillance, radiation treatment, and radical prostatectomy, respectively. Predictors for csPCa were presence of PI-RADS 5 lesions, age, length of time from MRI to biopsy, and smaller prostate volumes. MRI-TB yields high detection rates for csPCa in men with elusive PSA elevation and frequently guides a change in clinical management. Clinical decision-making based on MRI findings and PI-RADS lesion scores are best informed by an understanding of institutional reporting patterns.