==inizio objective==

Most prostate biopsies are driven by prostate-specific antigen (PSA) testing. However, as the positive predictive value of PSA has been significantly reduced over the last several years, more unnecessary prostate biopsies are performed annually on millions of men worldwide [1]. Moreover, transrectal ultrasound (TRUS)-guided biopsy, which is the standard procedure for prostate histological sampling, has a detection rate of about 40%, with a false negative rate of about 20% [2]. In this scenario more accurate methods need to be found to detect significant prostate cancer (PCa) or rule out patients with elevated PSA levels and insignificant lesions.
In the last decade, with the aid of multiparametric magnetic resonance (mp-MR) imaging, clinical relevant PCa foci could be better identified, sampled and treated than in the past. Hence more efforts are being made to incorporate mp-MR imaging into routine prostate biopsy, including cognitive, fusion, and in-bore MR-guided techniques [3].
Aim of this study is to compare PCa detection rate of in bore magnetic resonance (MR)-targeted biopsy with the detection rate of TRUS-guided prostate biopsy in patients with high PSA values and at least one suspicious region identified by the radiologist at mp-MR imaging.

==fine objective==

==inizio methodsresults==

The dataset of this study comprised 223 subjects referred for clinical suspicion of PCa who underwent mp-MR imaging. Of these, 51 patients (23%, median age: 68.4 years, median PSA: 7.5 ng/ml) showed at least one suspicious lesion at mp-MR imaging (median lesion diameter: 10 mm), with the characteristics of a clinically significant disease. Among these patients, 32 had at least one prior negative TRUS-guided biopsy (median of one session per patient, range 1-3). Then, they were randomly divided into two groups balanced with respect to age, PSA value, lesion size and location. Group A included 26 patients who underwent MR-targeted biopsy towards the MR findings. Two targeted cores were obtained from each lesion defined by the radiologist. Group B included 25 patients who underwent a TRUS-guided biopsy with saturation scheme including at least 28 cores. Biopsy specimens were fixed in formalin and underwent pathologic evaluation to define PCa presence and Gleason score.

==fine methodsresults==

==inizio results==

In group A, PCa was detected in 20 out of 26 (77%) cases, 6 of which were located in the transition zone. Five negative findings in group A were located in the peripheral zone, and one was found in the transition zone. In group B we found 18 out of 25 (72%) PCa, 6 of which were in the transition zone. Six negative findings in group B were located in the peripheral zone, and one in the transition zone. Detection rates between the two groups were not significantly different (p > 0.93). Results of pathologic evaluation are reported in Table 1.

==fine results==

==inizio discussions==

The results obtained from a dataset of 51 patients suggest that introducing a mp-MR exam before scheduling a prostate biopsy increases the detection rate of clinically significant PCa, whatever the biopsy technique used for sampling (MR targeted biopsy or TRUS-guided biopsy). This study also has some limitations: first, this is a single center trial and results may not be as easily reproduced as those of multicenter trials. Second, we included men without considering previous number of prostate biopsies performed. At last, in the TRUS-guided arm, cognitive targeting could not be avoided, therefore PCa detection rate in arm B may be overestimated.

==fine discussions==

==inizio conclusion==

In conclusion, this randomized controlled trial demonstrated that PCa detection rate of the MR-targeted and TRUS-guided are not statistically different, provided that an additional mp-MR examination is performed before biopsy. The potential benefits of mp-MR imaging are: i) accurate identification of significant cancer before biopsy, and ii) in positive cases it can localize the lesions and assess their local extent. Therefore the introduction of a prostate mp-MR exam before taking a decision on whether to perform biopsy may help to rule out subjects which would not benefit from further prostate sampling, and select patients with clinically relevant PCa without delay a radical treatment.

==fine conclusion==

==inizio references==

[1] Zlotta AR and Robert KN. To Biopsy or Not to Biopsy – Thou Shall Think Twice. Eur Urol 2012; 61: 1115-7
[2] Schoots IG, Roobol MJ, Nieboer D, et al. Magnetic Resonance Imaging–targeted Biopsy May Enhance the Diagnostic Accuracy of Significant Prostate Cancer Detection Compared to Standard Transrectal Ultrasound-guided Biopsy: A Systematic Review and Meta-analysis. Eur Urol 2015; 68: 438-50
[3] Acar Ö, Esen T, Çolakoğlu B, et al. Multiparametric MRI guidance in first-time prostate biopsies: what is the real benefit? Diagn Interv Radiol 2015; 21: 271-6

==fine references==