Multiparametric MRI fusion-guided prostate biopsy in biopsy naive patients: Preliminary results from 80 patients

The aim of this prospective study was to evaluate the early results of transrectal prostate biopsies performed under the guidance of multiparametric prostate magnetic resonance imaging (mpMRI) in biopsy naive patients.

Biopsy naive patients who had prostate-specific antigen level 4-10 ng/mL and/or abnormal digital rectal examination findings and provided informed consent were examined using mpMRI. The study included 80 patients with an MRI-defined lesion with a Prostate Imaging and Reporting and Data System (PIRADS) score of ≥3. All mpMRIs were reported by the same uro-radiologist according to PIRADS version 2. An MRI-targeted biopsy was performed by an ultrasonography system with rigid fusion registration software. The first two to five core biopsies per MRI-defined lesions were obtained, and then a standard random 12-core biopsy was performed. Transrectal biopsies were performed under local anesthesia or sedoanalgesia.

Of the 80 patients, 29 (36.3%) were found to have cancer using the conventional 12-core biopsy, but only 20 (25%) were found to have prostate cancer using the MRI-targeted prostate biopsy. Combining the two biopsy methods (conventional+MRI-targeted), cancer detection rate increased to 43.8% (35/80 patients). The cancer detection rate using the combined method was statistically higher than that using the conventional biopsy method (p=0.03). Using the conventional biopsy method, 960 core biopsies were collected from 80 patients. Of the 960 core biopsies, 111 (11.6%) were found to be cancer. Further, 101 suspected lesions were detected using mpMRI in 80 patients. In addition, 397 core biopsies were obtained from these lesions. Of the 397 core biopsies, 62 (15.6%) were reported as prostate cancer. The core positivity rate of MR-targeted biopsy was statistically higher than that of conventional biopsy (p=0.04).

The preliminary results of MRI-targeted prostate biopsy combined with conventional biopsy suggested that the combined biopsy method was crucial in prostate cancer diagnosis especially in patients with prostate cancer suspicion and no biopsy history. However, larger sample prospective studies are needed to validate the effectiveness of MRI-targeted biopsy and combined biopsy methods.