PD34-01 MR-US FUSION BIOPSY VS. TRUS SATURATION PROSTATE BIOPSY IN ACTIVE SURVEILLANCE

Abstract

INTRODUCTION AND OBJECTIVES: MR-US fusion biopsy (MR-US-FB) represents a potentially useful tool to assess for PCa progression in patients on active surveillance (AS). It is unknown whether MR-US-FB is superior to TRUS saturation biopsy to accurately characterize disease reclassification. We analyzed our initial experience with MR-US-FB compared with TRUS saturation biopsy in patients on AS. METHODS: 90 patients undergoing surveillance biopsy were analyzed. 35 patients with previously diagnosed PCa on active surveillance underwent MR-US-FB (UroNav, Invivo) with standard 12-core TRUS biopsy in same procedure from 7/2014-10/2014. Patients first had multiparametric prostate MRI (3T without endorectal coil) and target lesions of interest (LOI) for biopsy were marked. Median number of LOI/ patient was 2. Median number of cores per LOI was 3. These patients were compared to a cohort of 55 patients from 2011-2013 undergoing saturation ( 20 cores) TRUS biopsy as part of an active surveillance protocol. RESULTS: Overall, there was no difference between groups in cancer detection or reclassification (p>0.05). Results summarized in table below. The mean total number of cores was higher with saturation biopsy vs. MR-US-FB (20 1.5 vs. 18 5.4, p<.001). Number of previous biopsies was higher in the MR fusion group: (2.0 1.3 vs. 1.4 0.6, p1⁄40.02). Median PSA was 4.3 (IQR 3-6) in the MR fusion group vs. 5.6 (IQR 3.5-7.5) in the saturation biopsy group (p1⁄40.07.). Multivariable analysis of age, PSA, number of previous biopsies, biopsy type (MR vs. saturation), or total number of cores taken demonstrated no significant relationship with PCa diagnosis. 7/35 of MR biopsies showed PCa in both target and standard cores. Of these, 2 had no difference in Gl grade, 4 had higher Gl grade in the standard cores, and only 1 had higher Gl grade in target core. 16/35 patients had PCa present in standard cores only (2 of these were Gl 7). One patient had PCa in only targeted cores, and one patient had only target cores taken. CONCLUSIONS: There was no difference in rates of cancer detection, risk group reclassification, or reclassification by Gleason score upgrading between MR-US-FB and TRUS saturation biopsy in patients on AS. The majority of patients undergoing MR-US-FB had no Gleason upgrading when comparing cancer in standard TRUS cores to cores taken from target lesions.