Studies have demonstrated the clinical value of mpMRI and its use in guiding biopsy decision-making to increase the likelihood of detecting clinically significant prostate cancer while lowering detection of insignificant disease. While this is particularly true in patients with a prior negative prostate biopsy, more recent studies suggest that the mpMRI may have benefit in the screening setting. The PRECISION trial (Prostate Evaluation for Clinically Important Disease: Sampling Using Image-guidance or Not?) was a randomized non-inferiority study that sought to compare the effectiveness of MRI-targeted versus systematic biopsy in detecting clinically significant prostate cancer in biopsy-naïve patients.111 This 500-patient trial was performed at 25 centers in 11 countries, using 1.5T or 3T scanners, with or without an endorectal coil. There was no central reading of the MRI prior to biopsy, and biopsies were performed by transrectal or transperineal route, using a cognitive or ultrasound fusion technique. Hence, there was significant uncontrolled variability in reading of the MRI, method of biopsy, and fusion technique. Of patients who underwent an MRI, nearly 70% had a lesion targetable for biopsy (PI-RADS score ≥ 3). Clinically significant prostate cancer was detected in 38% of the patients undergoing mpMRI and 26% of patients undergoing systematic biopsy. Patients undergoing MRI-targeted biopsy also had fewer insignificant cancers detected (9% versus 22%). The agreement between a local and a central read for MRI was 78%, which was considered moderate. The MULTIPROS trial was a prospective, multicenter randomized study in the United Kingdom enrolling 413 biopsy-naïve patients with clinical suspicion for prostate cancer between 2015 and 2020. All participants underwent prebiopsy mpMRI, and those with suspicious lesions (PI-RADS ≥ 3) were randomized to systematic biopsy alone or combined MRI-targeted plus systematic biopsy. The study found that the combined approach significantly improved detection of clinically significant prostate cancer compared with systematic biopsy alone (adjusted odds ratio [aOR]: 1.79; 95% CI: 1.14 to 2.79; p=0.01). These results underscore that mpMRI guides lesion detection and augments biopsy strategy by increasing the yield of clinically significant cancers.112 Subsequent prospective trials in both initial diagnosis and screening settings provide evidence on outcomes among biopsy-naïve patients with negative MRI findings. In a follow-up report of the Göteborg-2 screening trial, a PSA+MRI strategy allowed those with negative MRI to avoid biopsy, leading to more than a 50% reduction in detection of clinically insignificant cancer without an excess of advanced or metastatic disease after a relatively short follow-up of 4 years. The relative risk of detecting clinically significant prostate cancer in the targeted biopsy group compared with the systematic biopsy group was modestly lower (RR: 0.84; 95% CI: 0.66 to 1.07) and not statistically significant.113 Similarly, the PROKOMB trial prospectively evaluated an MRI-informed biopsy strategy in biopsy-naïve patients with elevated PSA across multiple German centers. All participants underwent prebiopsy MRI; those with PI-RADS ≥ 3 lesions were recommended for targeted plus systematic biopsy, while those with negative MRI (PI-RADS 1 to 2) were advised to defer biopsy and instead undergo structured surveillance with serial PSA, DRE, and repeat MRI or biopsy only if risk indicators emerged. A total of 593 patients underwent mpMRI with 286 (48%) having negative MRI results, 261 (44%) avoiding biopsy initially, and 242 (41%) avoiding biopsy over 3 years. Of the 286 patients with a negative MRI, 25 (9%) underwent immediate biopsy with detection of 7 (28%) prostate cancers, of which 4 (57%) were GG2+. During three years of structured follow-up, an additional 44 (15%) patients from the negative-MRI group underwent biopsy, and clinically significant prostate cancer was detected in 7 (16%). No cases of metastatic disease were reported over a short monitoring period of 3 years.114 The PROBASE trial, a large German population-based, risk-adapted screening study, enrolled approximately 46,000 patients aged 45, who were randomized to immediate or delayed PSA testing as part of a long-term prostate cancer early-detection strategy. In the first screening round, of 186 participants with elevated PSA (≥ 3 ng/mL), 114 (61%) underwent mpMRI, followed by a combined targeted plus systematic biopsy if the PI-RADS score was ≥ 3. Among these 114 patients, 47 (41%) were diagnosed with prostate cancer, with 33 (29%) having clinically significant disease. For scans interpreted centrally by experienced reference radiologists, using PI-RADS ≥ 4 as the biopsy threshold yielded 79% sensitivity, 91% negative predictive value (NPV), and 85% accuracy for clinically significant cancer. In contrast, local MRI reads performed substantially worse using the same PI‑RADS ≥ 4 threshold: only 55% sensitivity, 80% NPV, and 68% accuracy in identifying clinically significant prostate cancer. Furthermore, interobserver agreement between local and expert readings was moderate (κ=0.41), indicating only modest consistency in MRI interpretation across settings. These results emphasize that the oncologic safety of avoiding biopsy in patients with negative MRI (PI-RADS 1 to 2) depends heavily on high-quality imaging and expert interpretation.115 Prospective randomized studies that compared mpMRI driven biopsy to standard systematic biopsy in biopsy-naïve patients, used varying reference standards such as radical prostatectomy findings or saturation biopsy findings to assess the accuracy of mpMRI.116 Some do not list a reference standard.117 Data on patients with no MRI-detected, biopsy-eligible lesions, are also not provided but these patients could subsequently be diagnosed with prostate cancer including clinically significant prostate cancer. Different techniques have been utilized to perform MRI-guided biopsy, such as cognitive versus image-guided fusion. Patients in the MRI arm have also undergone standard systematic biopsies in addition to MRI-guided biopsy. In some studies, those with negative MRI results have crossed over to systematic biopsy.116, 118 For instance, Hugosson et al. sought to examine the independent value of systematic biopsies in patients who had undergone an MRI following an elevated PSA. They found that avoidance of routine systematic biopsies and performing only MRI-directed biopsies reduced the detection of clinically insignificant cancers. However, all individuals in this study underwent an mpMRI, and it did not address the question of the need for routine MRI before biopsy. Patients with a PSA > 10 ng/mL and all patients with a diagnosis of cancer on MRI-guided biopsy were offered systematic biopsies as well. Performance of systematic biopsies did result in detection of clinically significant prostate cancer (including a Gleason 3+5) which was missed on MRI-guided biopsy in a small subset of people.119 Importantly, a Cochrane review on this topic pooled data from 18 studies that included biopsy-naïve patients and patients with prior negative prostate biopsy.120Analysis of the pooled data suggests the sensitivity of a pre-biopsy MRI is 0.91 (95% CI: 0.83 to 0.95), and specificity is 0.37 (95% CI: 0.29 to 0.46) for GG2+ prostate cancer. The pooled prostate cancer detection ratio for MRI prior to initial biopsy was 1.05 (95% CI: 0.95 to 1.16), which indicates prior MRI may have limited benefit in this setting. However, when considering patients who had undergone pre-biopsy MRI followed by a targeted and systematic biopsy compared to systematic biopsy alone, the pooled analysis found an additional 10 patients (out of 100 biopsied) would be diagnosed with clinically significant prostate cancer. The reference standard utilized for this analysis was detection of clinically significant cancer on template biopsy. The study found there to be significant heterogeneity in study conduct as well as high risk of bias in sample selection and reference standard. Hence, the study authors graded the evidence as low. While it is reasonable to routinely obtain an mpMRI in biopsy-naïve patients, the dependance of the outcomes on image quality and expert interpretation tempers the enthusiasm for a stronger recommendation. Recognizing this challenge, multiple U.S. initiatives—particularly those led by the American College of Radiology (ACR)—have sought to enhance and standardize prostate MRI through structured quality-improvement collaboratives, education efforts, and accreditation programs that promote high-quality acquisition, interpretation, and reporting across diverse practices.121 As in the PSA screening setting, the use of SDM is highly recommended given the uncertainty involved.