The role of MRI-guided biopsy for diagnosis of prostate cancer; comparison between FUSION and "IN-BORE" approaches.

BACKGROUND The aim of the present study is to evaluate the difference in terms of feasibility and detection rate of two magnetic resonance imaging (MRI) guided biopsy approaches (MRI fusion versus "in-bore" MRI) in a single tertiary centre. METHODS We retrospectively identified 297 patients with suspected prostate cancer who underwent MRI based target prostate biopsy (FUSION or "in-bore" approaches) between January 2016 and January 2018 in a single tertiary centre. RESULTS Lesion site (peripheral vs central) and localization (anterior vs posterior) were equally comparable among two groups, but maximum diameter of multiparametric-MRI index lesion was slightly superior in the in-bore MRI-GB group (14 vs 12 mm, p=0.002). Mean random biopsy cores taken were 11.2±2.1, with 1.3±2 positive cores in FUSION-GB group. Mean number of targeted biopsy cores taken was significantly superior in the FUSION-GB group as compared to the in-bore MRI-GB group(2.6±0.7 vs 1.7±1, p<0.001), whereas mean number of positive targeted biopsy cores was comparable between two groups (1±1.3 vs 1±0.9, p=0.1). 70 (45.5%) and 75 (52.8%) patients had positive targeted bioptic cores at pathologic examination among FUSION-GB and in-bore MRI-GB groups, respectively (p=0.2). Bioptical ISUP grade was also comparable among two groups (p=0.2) in multivariate analysis PI-RADS score (OR=3.04 and OR=8.32 for PI-RADS 4 and 5, respectively) and PSA density (OR=2.69) were identified as independent predictors of positive targeted cores at histological examination (p<0.001 and p=0.01, respectively). CONCLUSIONS In-bore MRI-GB approaches represent a promising technique that may offer some advantages compared to standard systematic FUSION-GB despite higher costs of in bore-procedure. Our experience, although not showing a clear advantage between the FUSION technique and the "in- bore" technique, resulted safe and feasible and represents a viable procedure for the diagnosis and characterization of prostate especially in a subgroup of patient with clinically significant disease. Further investigations are needed in order to identify the best approach for MRI-GB.