Purpose: Prostate cancer is the most commonly diagnosed solid tumor in men. The diagnosis, however, still relies on low sensitivity studies (PSA, digital rectal examination (DRE) and random TRUS directed biopsy). Active surveillance is an alternative option to manage patients with low-grade cancer. These patients need reliable tools for follow-up. MRI has become the best imaging modality for prostate cancer detection and local staging. Therefore, targeted MR guided biopsy seems as the most promising procedure for cancer detection. The purpose of our study was to determine the feasibility and reliability of in-bore MRI transrectal biopsy (MRGB) in detection of prostate cancer and reevaluation for active surveillance patients.
Methods: We retrospectively reviewed the hospital records of 66 patients between March 2016 and June 2017. All patients had a prior mutliparametric MRI (mpMRI). Included were patients on active surveillance and those suspected to have cancer (based on PSA elevation, suspicious DRE, negative prior biopsies). All mpMRI studies were evaluated by a single experienced uro-radiologist, using PIRADS (Prostate Imaging Reporting and Data System) scoring. 22 patients were excluded for biopsy due to a time interval of 1 year since last mpMRI, PIRADS less than 3 and inappropriate images. Targeted and random biopsies were performed by an experienced urologist guided by the radiologist. Procedures were done under deep sedation by an anesthesiologist. Correlation between PIRADS score and Gleason score from the specimens, was evaluated.
Results: 44 patients with a mean age of 69 had MRGB. Mean PSA level was 8.8. 24 patients for detection (8 pre-biopsy, 16 prior negative biopsy), and 20 on active surveillance. 20 lesions scored PIRADS3 (45.4%), 16 PIRADS4 (36.4%) and 8 PIRADS5 (18.2%). Clinically significant tumors, Gleason ≥7, were found in 3/20 (15 %) PIRADS3 lesions, 10/16 (62.5%) PIRADS4 lesions and 6/8 (75%) PIRADS5 lesions. Patients were discharged after short supervision without any immediate major complications.
Conclusion: In bore MRI guided biopsy is not a complicated procedure. It has very good accuracy for prostate cancer detection. These findings may have important clinical impact on the management of patients.
