PD4-11 THE RELATIONSHIP OF INCREASING MRI SUSPICION SCORE AND THE IDENTIFICATION OF HIGH GRADE PROSTATE CANCER ON MRI FUSION TARGETED BIOPSY.

Abstract

INTRODUCTION AND OBJECTIVES: Multi-parametric MRI (mpMRI) suspicion scores (mSS) can help predict the likelihood of prostate cancer (PCa) on prostate biopsy (PB). In combination with MRI fusion targeted biopsy (MRF-TB), mSS has the potential to reduce over-detection of indolent PCa through avoidance of low risk biopsies. In this study we report the relationship of mSS and PB outcomes among men undergoing systematic biopsy (SB) and MRF-TB following mpMRI. METHODS: Between 6/2012 and 8/2014, all 824 men presenting to our institution for prostate biopsy underwent pre-biopsy mpMRI followed by PB. Outcomes were recorded in an IRB-approved database. For this analysis, biopsy results and mSS were queried from those who underwent both SB and MRF-TB using the Artemis/Profuse (Eigen, Grass Valley) co-registration system. RESULTS: 604 men (mean age 65 8 years; BMI 27.1 4.3; PSA 6.7 7.2 ng/ml) met inclusion criteria. Overall, increasing mSS correlates with a step-wise increase in detection of GS 7 PCa with both SB [r1⁄4.95] and MRF-TB [r1⁄40.95]. This finding is not seen in GS6 PCa detection with either SB [r1⁄4-0.10] or MRF-TB [r1⁄4-0.23] (See figure 1). For mSS 4/5, MRF-TB detected fewer GS6 PCa [p1⁄40.013] and detected more GS 7 PCa [p1⁄40.001] as compared to SB. When evaluating the cohort by PB indication, for mSS 4/5, FB detected less GS6 PCa than SB only in biopsy naive men [p1⁄40.021], but was similar to SB in men with prior negative PB [p1⁄40.628] or on active surveillance [p1⁄40.114]. However, FB detected more GS 7 PCa compared to SB in all three cohorts with mSS 4/5 [p<0.05 in all 3 cohorts] (See table 1). CONCLUSIONS: Increasing mSS correlates with a higher likelihood of detection of high grade PCa in all men. While this correlation exists with both SB and MRF-TB, in men with mSS 4/5, MRFTB is better at detecting GS 7 PCa while avoiding over-detection of GS6 PCa. In addition, combining mSS and the difference in CDR by biopsy indication can ultimately help identify select men in whom prostate biopsy is unlikely to detect GS& 7 PCa, and PB may be avoided.