63 Background: Active surveillance (AS) is an option for patients with low risk prostate cancer (PCa); however, determining disease progression is challenging. At the NCI, multiparametric MRI (MP-MRI) with our biopsy protocol (MR-US fusion-guided plus 12 core extended sextant biopsy) has been used to confirm eligibility for AS. We evaluated the utility of these modalities in monitoring patients on AS. Methods: Patients who underwent MP-MRI of the prostate with biopsy per our protocol between 2007-2012 were reviewed. We selected a subset who met Johns Hopkins criteria for AS (Gleason score≤6, PSA density≤0.15, tumor involvement of ≤2 cores, and ≤50% of any single core) by outside 12−core TRUS biopsy. Patients with Gleason score≤6 confirmed at first NCI biopsy session were followed with annual MP-MRI and biopsy. MRI progression was defined as an increase in MP-MRI suspicion level, lesion diameter, or number of lesions. Pathologic progression was defined as an increase to Gleason score≥7 in either 12-core or MR-fusion biopsy. We determined the association between MRI and pathologic progression. Results: 129 patients met JHU criteria for AS by outside biopsy. Mean age was 61.6 years and mean PSA 5.16ng/mL. 28/129 (21.7%) patients had Gleason score ≥7 at first NCI biopsy session.31 patients had at least two biopsy sessions (mean follow up 18 months, range 12-54 months) of which 9/31 (29%) increased in Gleason score, all to 3+4=7. Fusion biopsy detected more pathologic progression than did standard biopsy (Table). The positive predictive value of MP-MRI for pathologic progression was 50%, while the negative predictive value was 84%. The sensitivity and specificity of MP-MRI for increase in Gleason score was 67% and 73%, respectively. Conclusions: Stable findings on MP-MRI are associated with Gleason score stability in patients with low-risk PCa choosing AS. The majority of patients who had pathologic progression were detected on fusion biopsy, which may suggest that random biopsies are unnecessary in this population. Larger studies are needed to validate these findings. [Table: see text]
Evaluation of Magnetic Resonance Imaging/Ultrasound-Fusion Biopsy in Patients with Low-Risk Prostate Cancer Under Active Surveillance Undergoing Surveillance Biopsy
