MP13-02 IN MEN WITH PROSTATE MRI LESIONS, WHEN CAN WE FORGO SYSTEMATIC BIOPSIES?

Abstract

INTRODUCTION AND OBJECTIVE: Multiple recent studies have suggested combined MRI-targeted and 12-core systematic biopsies lead to improved clinically significant cancer detection. However, increasing the number of prostate biopsy cores can increase urinary and infectious complications. We sought to determine if systematic biopsy could be safely forgone in some patients based on pre-biopsy PIRADS score. METHODS: Between April 2015 and January 2019, patients enrolled in a prospective nationally registered clinical trial evaluating the use of MRI-targeted fusion biopsy(NCT00102544). All patients with MRI visible lesions underwent MRI-targeted and systematic biopsies during the same setting for prostate cancer diagnosis. The highest Gleason Grade(GG) cancer detected by each biopsy method was recorded and stratified by MRI PIRADS v2 score. Additional clinically significant cancer(GG 4+3=7) detected by MRI targeted or systematic biopsy were calculated. RESULTS: In total, 723 men with PIRADS≥2 lesions underwent prostate biopsy. PIRADS score of 2, 3, 4, and 5 lesions were detected in 51(7.1%), 87(12.0%), 346(47.9%), and 239(33.1%) biopsied men, respectively. Among PIRADS 5 (n=239) patients, cancer was diagnosed in 226(94.6%). If MRI targeted biopsies were performed, the addition of systematic biopsies only led to 0.8% (n=2) more detection of GG≥3 patients. In both of these patients, the MRI targeted biopsy alone characterized these patients as GG=2 cancer whereas systematic biopsy diagnosed them as GG=3 cancer. Men with PIRADS scores of 4, 3, and 2 had greater rates of additional GG≥3 cancer detection by systematic biopsy compared to PIRADS 5 lesions (See Table). Of men with PIRADS 4, 3, and 2 scores, 12(3.5%), 3(3.5%), and 1(2%) patients were diagnosed with GG≥3 cancer by systematic biopsy alone, respectively, and 26(7.5%), 2(2.3%), and 1(2%) patients were diagnosed by MRI-targeted biopsy only, respectively. Combination biopsy of these patients had a greater likelihood of detecting clinically significant cancer than either targeted or systematic biopsy alone. CONCLUSIONS: For men with PIRADS 5 lesions on prostate MRI, omission of systematic biopsies in favor of targeted biopsy alone leads to a marginal decline in cancer diagnosis. However, for PIRADS 2-4 lesions, systematic biopsy adds significant diagnostic value and should be considered in combination with MRI-targeted biopsy.Source of Funding: This research was funded by the Intramural Research Program of the NIH.