In patients with a previous negative prostate biopsy and a suspicious lesion on MRI, is a 12-core biopsy still necessary in addition to a targeted biopsy?
OBJECTIVES: To evaluate the performance of multiparametric MRI (MP-MRI) in predicting CaP on repeat biopsy; and to compare the cancer detection rates (CDR) of MRI/TRUS fusion-guided biopsy with standard 12-core biopsy in men with at least one previous negative biopsy. MATERIALS AND METHODS: We prospectively enrolled men with elevated or rising PSA and/or abnormal DRE into our MRI/TRUS fusion-guided prostate biopsy trial. Participants underwent a 3T MP-MRI with an endorectal coil. Three radiologists graded all suspicious lesions on a 5-point Likert scale. MRI/TRUS fusion-guided biopsies of suspicious prostate lesions and standard TRUS-guided 12-core biopsies were performed. Analysis of 140 eligible men with at least one previous negative biopsy was performed. We calculated CDR and estimated area under curves (AUCs) of MP-MRI in predicting any and clinically significant CaP. RESULTS: The overall CDR was 65.0% (91/140). Higher level of suspicion on MP-MRI was significantly associated with prostate cancer detection (p< 0.001) with an AUC of 0.744 compared with 0.653 and 0.680 for PSA and PSA density respectively. The CDRs of MRI/TRUS fusion-guided and standard 12-core biopsy modalities were 52.1% (73/140) and 48.6% (68/140) respectively (p = 0.435). However, fusion biopsy was more likely to detect clinically significant CaP when compared with the 12-core modality (47.9% vs. 30.7%; p < 0.001). Of the cancers missed by 12-core, 20.9% (19/91) were clinically significant. Most cancers missed by 12-core (69.6%) were located in the anterior fibromuscular stroma and central gland. Using a Fusion biopsy only approach in men with an MRI suspicion score of >/= 4 would have missed only 3.5% of clinically significant CaP. CONCLUSIONS: MP-MRI and subsequent MRI/TRUS fusion-guided biopsy platform may improve detection of clinically significant CaP in men with previous negative biopsies. Addition of a 12-core biopsy may be needed to avoid missing some clinically significant CaP.