Magnetic Resonance Imaging Targeted Biopsy in Men with Previously Negative Prostate Biopsy Results

Abstract

To evaluate the efficacy of targeted prostate biopsy using magnetic resonance imaging (MRI) and to characterize clinicopathologic features of tumors detected with targeted prostate biopsy in men with previous negative prostate biopsy results. We prospectively studied 87 patients with a persistently increasing level of serum prostate-specific antigen (PSA), at least one previous set of negative 12-core prostate biopsies, and normal digital rectal examination. All patients were examined with combined T2-weighted and diffusion-weighted MRI before undergoing the prostate biopsy. Prostate biopsy was performed using transrectal ultrasonography-guided standard 12 cores plus targeted biopsy to suspicious region(s) as identified on T2 images on their MRI. Of a total of 87 cases, 82 (94.2%) patients had suspicious lesion(s) on their MRI. Of these 82 patients, 46 (56.0%) patients had prostate cancer (PCA) as determined by the biopsy. The patients with PCA showed a significantly higher incidence of having suspicious lesion(s) (the anterior or apex) on MRI than the patients without PCA (P<0.05). On analysis by dividing all biopsy cores into the targeted cores and standard cores, PCA was found in 149/518 (28.8%) MRI-targeted cores and in 32/903 (3.6%) standard cores (P=0.012) Of 43 patients who underwent radical prostatectomy, 37 (86.0%) patients were detected with PCA located at the anterior or apex portion of the prostate. For tumor characteristics according to tumor locations, there was no significant correlation between tumor location and Gleason scores or pathologic stage. Our data suggest that a MRI-targeted prostate biopsy after prostate MRI might be considered for the identification of cancer foci and the detection of PCA, for patients with a previous negative standard prostate biopsy result despite a persistently elevated PSA value.