MP05-13 PROSTATE MRI BEFORE RADICAL PROSTATECTOMY DOES NOT AFFECT MARGINS AND FUNCTIONAL OUTCOMES

Abstract

INTRODUCTION AND OBJECTIVES: Multiparametric MRI of the prostate (mpMRI) is an evolving technology that provides both imaging and functional information of the prostate to distinguish benign from malignant lesions. The majority of reports on the benefits of mpMRI have emanated from clinical studies at high volume centers and the adoption of mpMRI at broader institutions is unclear. We hypothesized that mpMRI is becoming rapidly adopted in the US to fill the unmet need for a non-invasive but highly accurate screening tool. METHODS: IRB-approved single institutional review from October 2013 to July 2015 of all consecutive patients who underwent mpMRI on a 3.0-T MRI with T1-weighted, triplanar high resolution T2weighted, dynamic contrast-enhanced MR, and diffusion-weighted imaging. RESULTS: A total of 1,118 mpMRI of the prostate were performed with a 286% increase over 22 months, increasing from 24 mpMRI/month in November 2013 to 72 mpMRI/month in July of 2015 (figure 1). The most common indications for mpMRI (60%) were prostate cancer screening including elevated PSA (60%) and abnormal DRE (4%). After mpMRI for abnormal screening, 47% of men underwent a prostate biopsy, either by cognitive mapping (65%) or MR-US fusion targeting (35%). This data suggests that MRI may have prevented biopsy in 261 men over 22 months. The rate of cancer detection on fusion biopsies was 48%, which is significantly greater than biopsies performed at the same time without imaging (32%, p1⁄40.03). 12.7% of mpMRI were performed on patients considering or enrolled in active surveillance of prostate cancer, 7.5% on patients for clinical staging, and 3.2% by radiation oncologists planning radiotherapy. 7% of all mpMRI were performed to evaluate the pelvis for biochemical recurrence after definitive treatment. Among these, 36% identified an area of suspicion for targeting with further therapy. CONCLUSIONS: Prostate mpMRI is increasingly performed for both the diagnosis and management of prostate cancer. As clinical utilization increases, the rate of unnecessary biopsies may decrease further. Prospective trials are necessary to compare the effectiveness and safety of imaging-based decision making for prostate cancer.