Evaluation of MR imaging-targeted biopsies of the prostate in biopsy-naïve patients. A single centre study.

PURPOSE: To evaluate the differences in prostate cancer detection rate and biopsy effectiveness between magnetic resonance imaging (MRI) target biopsy (TB) and transperineal standard biopsy (SB) in biopsy-naïve patients. MATERIAL AND METHODS: Between October 2014 and April 2016, 60 men with a mean age of 64.1±6.7 (SD) years (range: 53-82 years) were prospectively enrolled. All patients underwent a prostate MRI study, evaluated by two radiologists, before undergoing the biopsy. A transperineal 12-core SB was carried out before TB, without the information from the MRI. The detection rate for all tumors and for clinically significant tumors (CS) was recorded. Sampling variables such as the proportion of cores positive for CS cancer (PCP-CS) and the maximum cancer core length (MCCL) were also calculated. The ability of MRI to predict the presence of a CS tumor at biopsy was studied using a sector analysis. Patients with negative biopsies were followed during a minimum of 12 months. RESULTS: The detection rate for SB and TB was 53.3% (32/60) and 46.7% (28/60) respectively for all tumors (P=0.289) and 45% (27/60) in both techniques for CS tumors. TB obtained a larger PCP-CS (P<0.001) and MCCL (P=0.018). The sensitivity, specificity, positive predictive value, negative predictive value and cancer prevalence was 83.3%, 92.9%, 83.3%, 92.9% and 30% for peripheral zone sectors and 43.8%, 97.1%, 70.0%, 91.8% and 13,3% for transitional zone sectors. The proportion of patients that showed an increase of PSA faster than 0.75ng/mL/year after a negative biopsy was 26.1%. CONCLUSION: Detection rate of prostate cancer did not show significant differences between a TB and a SB technique in biopsy-naïve patients. However, targeted prostate biopsies demonstrated a better sampling effectiveness thus reducing the cores needed to diagnose clinically significant tumors.

Usefulness of cognitive targeting in multiparametric MRI-guided biopsy to diagnose the dominant lesion in prostate cancer.

OBJECTIVE: To evaluate the safety and efficacy of cognitive targeting in multiparametric MRI-guided biopsy to obtain samples of the dominant nodule in prostate cancer. MATERIAL AND METHODS: We performed cognitive-targeted biopsy after multiparametric MRI in 53 patients with progressive elevation of PSA. All patients provided written informed consent. Biopsies were done via a transperineal route under ultrasound guidance. The first three samples were obtained by cognitive targeting, with the target lesion determined by multiparametric MRI according to the PI-RADS (prostate imaging, reporting, and data system) criteria. Then 9 cylinders were obtained from the remaining segments of the prostate (systematic biopsies). The pathologist evaluated the 12 cylinders without knowing which ones were obtained by cognitive targeting. In patients with multifocal lesions, we defined the dominant lesion as the one with the highest Gleason score and tumor volume; in patients with unifocal lesions, we defined the dominant lesion as the lesion identified. RESULTS: We diagnosed 29 prostate tumors. In 89.7% (26/29), the dominant nodule was diagnosed by the cognitive-targeted biopsy. If only cognitive-targeted biopsy had been done, the dominant nodule would not have been diagnosed in two (3.8%, 2/53) patients and only one (1.8%, 1/53) patient, in whom no sample was obtained from the lesion with the highest Gleason score, would have been understaged. The rate of positivity of cognitive-targeted biopsy was 50.9% (27/53) in the entire group of patients and 46.3% (19/41) in the group of patients with previous negative biopsies. No significant immediate or late complications were observed. CONCLUSION: Cognitive targeting is safe and efficacious for detecting the dominant lesion in prostate cancer.