Papers & Publications

Introduction: Prostate cancer (PCa) screening is increasingly guided by imaging. High-resolution 29 MHz Micro-Ultrasound (MUS) offers a promising alternative to magnetic resonance imaging (MRI).

Methods: We retrospectively analyzed 682 consecutive men undergoing MUS and PSA testing during routine examination. Biopsy and MRI were performed according to guideline recommendations. PSA density (PSAD)-modified negative MUS included PRI-MUS categories 1, 2, or 3 with PSAD < 0.15 ng/mL2; PSAD-modified positive MUS included PRI-MUS categories 3 with PSAD ≥ 0.15 ng/mL2, 4 or 5.

Results: Median age was 59 years; median PSA 1.2 ng/mL (IQR: 0.6–3.5). Biopsies were performed in 62 men, detecting PCa in 29 (47%), including 18 (29%) clinically significant PCa (csPCa). 88 men (13%) had PSAD-modified positive MUS, yielding 15 csPCa and 7 non-clinically significant PCa (ncsPCa). Among 594 men (87%) with PSAD-modified negative MUS, 3 csPCa and 4 ncsPCa were detected. Compared to PSA-based biopsy indication ≥3 ng/mL, PSAD-modified negative MUS would have avoided 13 negative, missing two csPCa and four ncsPCa. Compared to the MRI-based biopsy indication (PI-RADS ≥ 3, n = 38), PSAD-modified negative MUS (n = 594) would have spared 3 negative biopsies, as well as 17 (24.7% of 69) MRIs due to negative biopsy, while missing 0 cases of csPCa. Additionally, MRI could have been omitted in 1csPCa case and 9 ncsPCa cases with positive MUS, and in 13 csPCa and 7 ncsPCa cases based on PSAD-modified positive MUS. The PSAD-modified-PRI-MUS-based screening pathway showed a 6.29-fold (OR = 0.16) reduction in overdiagnosis and 7.22-fold (OR = 0.14) reduction in negative biopsies/ncsPCa. MUS without PSA demonstrated an OR of 7.30 to detect csPCa. PSAD-modified-PRI-MUS score demonstrated a sensitivity of 83.3%, a specificity of 59.1%, a positive predictive value of 45.5% and a negative predictive value of 89.7% for distinguishing csPCa from benign/ncsPCa findings.

Conclusion: MUS enables effective PCa risk stratification in an opportunistic screening setting supporting prospective trial development.

Background: Accurate detection and local staging of prostate cancer (PCa) remain critical for treatment planning, yet head-to-head multimodal imaging comparisons remain limited.

Objective: This study compared microultrasound (microUS), multiparametric magnetic resonance imaging (mpMRI), and prostate-specific membrane antigen positron emission tomography/computed tomography (PSMA PET/CT) for detecting clinically significant PCa (csPCa) and extraprostatic extension (EPE), using whole-mount histopathology (WMHP) as the reference standard.

Design, setting, and participants: This retrospective study included patients who underwent microUS and mpMRI followed by radical prostatectomy between January 2023 and October 2024. A subset also underwent PSMA PET/CT.

Outcome measurements and statistical analysis: Detection of csPCa and EPE was assessed at the lesion and sector levels using WMHP as a reference. Detection rates and positive predictive values (PPVs) were compared using McNemar and chi-square tests, while sector-level area under the receiver operating characteristic curves (AUCs) were compared using the DeLong test.

Results and limitations: No statistically significant differences were observed between microUS and mpMRI or PSMA PET/CT for index lesion detection (0.90, 0.94, and 0.93, respectively) or csPCa detection (0.71, 0.78, and 0.72, respectively), although the study may have been underpowered to detect small differences. mpMRI had higher PPVs for csPCa than microUS (0.91 vs 0.77, p = 0.03). mpMRI achieved the highest sector-level AUCs for csPCa (0.73) and EPE (0.88). Across modalities, 15–18% of csPCa lesions were missed, which were non-index Grade Group 2 with Gleason pattern 4 ≤20%. The study is limited by its single-center retrospective design.

Conclusions: MicroUS showed no statistically significant differences compared with mpMRI and PSMA PET/CT for detecting index and csPCa lesions, supporting a potential complementary role in resource-limited or MRI-contraindicated settings.

Objective: To analyze whole-mount (WM) pathology slides and to evaluate prostate ductal anatomy as a potential contrast mechanism for visualization of prostate cancer using micro-ultrasound.

Methods: Ten men scheduled to undergo radical prostatectomy for prostate cancer (PCa) were enrolled in an IRB-approved study. After prostatectomy, prostates were grossed, sectioned, and stained. All clinically significant PCa lesions were annotated by an experienced pathologist. The scanned slides were then analyzed using a custom computer vision script (MATLAB) to identify and quantify ductal features. Using the annotated lesions, binary masks were made to delineate benign and PCa groups. A color thresholding step was then applied to the tissue within each mask to select the white space where the prostate ducts are located. We extracted 2 main features as follows: the duct equivalent diameter and the ductal ratio, defined as the proportion of tissue area occupied by prostate ducts.

Results: A total of 54 slides were processed, with 145,150 benign and 9245 PCa ducts identified. The mean equivalent diameter of benign ducts was 155.7 ± 147.8 µm. PCa ducts had a mean equivalent diameter of 129.4 ± 94.3 µm. The average ductal ratio for benign tissue was 0.086 ± 0.029 and 0.039 ± 0.017 for PCa tissue.

Conclusion: Prostate ducts are large enough to be resolved on micro-ultrasound but too small for conventional ultrasound. In addition, PCa tissue exhibits an approximate 50% reduction in ductal ratio, which highlights the potential of ductal anatomy as a contrast mechanism for PCa visualization using micro-ultrasound.

Background: Prostate cancer is highly prevalent, and diagnostic pathways must maximize detection of clinically significant disease (csPCa) while minimizing overdiagnosis and resource burden. Micro-ultrasound (microUS) offers real-time, high-resolution lesion targeting and could reduce reliance on pre-biopsy MRI. We compared csPCa detection and diagnostic accuracy between microUS-targeted biopsy (microUS-TBx) and MRI-targeted biopsy (MRI-TBx).

Methods: Systematic searches of MEDLINE (PubMed), Embase, and ClinicalTrials.gov were completed on July 4, 2025 and updated Aug 5, 2025. Eligible studies directly compared microUS-TBx with MRI-TBx in adults undergoing prostate biopsy and reported csPCa (typically ISUP ≥2).

Primary endpoint: per-patient csPCa detection.

Secondary endpoints: sensitivity and specificity for csPCa. Random-effects meta-analysis (Hartung-Knapp) estimated detection ratios (microUS/MRI); heterogeneity was summarized with I². Diagnostic accuracy was synthesized using a bivariate random-effects model. Prespecified analyses included biopsy-naïve status, use of concomitant systematic cores, and risk of bias (QUADAS-2). PROSPERO registration pending at submission.

Results: Twenty-two studies (including one randomized trial) were included. Micro-US-TBx detected 2,194 csPCa cases; MRI-TBx detected 2,237. The pooled detection ratio (Micro-US vs MRI) was 0.99 (95% CI, 0.88–1.11; I² = 78.5%), indicating comparable yield. Pooled sensitivity/specificity were 0.86/0.38 for Micro-US-TBx and 0.84/0.40 for MRI-TBx. Heterogeneous biopsy triggers (e.g., PI-RADS ≥3 only vs biopsy-all) and frequent use of concomitant systematic biopsy introduced spectrum and partial verification/incorporation biases, which may shift detection rates, limit generalizability to routine care, and obscure standalone modality accuracy.

Conclusions: Micro-US-TBx demonstrated csPCa detection and diagnostic accuracy comparable to MRI-TBx. Given potential advantages in access and cost, MicroUS is a viable alternative for integration into prostate cancer diagnostic pathways, particularly in resource-limited settings.

Introduction: ExactVu micro-ultrasound generates high-resolution images and prom-ises to improve prostate biopsy performance, while transperineal prostate biopsy (TPB) has gained popularity due to its sterile technique. The aim of this study was to compare TPB using ExactVu to transrectal biopsy (TRB).

Methods: A retrospective analysis of patients who underwent TPB (n=306) using ExactVu or TRB (n=392) from 2019-2023 was performed. Clinical parameters were compared between the groups using Chi-squared test. Putative predictors of cancer on biopsy and upgrading on radical prostatectomy were investigated using logistic regression.

Results: More transperineal than transrectal biopsy patients had a Prostate Imaging-Reporting and Data System (PI-RADS) 5 lesion (40% vs. 28%, p=0.001) and were biopsy-naive (53% vs. 39%, p<0.001). In patients with no previous diagnosis of prostate cancer, the clinically significant prostate cancer detection rate was higher in the TPB group (53% vs. 42%, p=0.01). Transperineal patients required fewer cores to obtain equal cancer detection rates (11±5 vs. 15±4 cores, p<0.01). Upgrading from grade group 1 to grade group ≥2 on radical prostatectomy was more common with TRB (9.1% vs. 2.1%, p=0.04). Urinary retention rate did not differ by biopsy type and two transrectal but no transperineal patients developed urosepsis.

Conclusions: TPB required fewer cores to obtain a similar clinically significant prostate cancer detection rate when compared to TRB. TPB had fewer complications and a low upgrade rate. This suggests that cognitive fusion TPB using ExactVu is an excellent alterna-tive to software fusion TRB.

Introduction: Multiparametric (mp) magnetic resonance imaging (MRI) is essential for prostate cancer (PCa) detection but is limited by availability, cost, and complexity. Micro-ultrasound (microUS) offers real-time, high-resolution imaging and may enhance clinically significant (cs) prostate cancer (PCa) detection when used with mpMRI. This study updates the diagnostic performance of microUS compared to mpMRI in a large prospective cohort.

Materials and Methods: We prospectively enrolled 1, 423 men with suspected PCa between October 2017 and April 2024. All patients underwent imaging with the ExactVu system, followed by both microUS-targeted and MRI-targeted biopsies. The primary outcome was the accuracy of detecting csPCa, defined as Gleason score ≥3 + 4 (International Society of Urological Pathology Grade Group ≥2), comparing microUS, mpMRI, and their combined use.

Results: CsPCa was diagnosed in 116 (36.3%) patients. MicroUS detected lesions in 1, 076 out of 1, 423 patients (76%) of patients, with a sensitivity of 85% and a negative predictive value of 79% for csPCa. Concordance between microUS and mpMRI findings was 96%. In total, 252 patients (18%) were diagnosed with PCa solely on targeted cores. Among these, 25 csPCa cases were identified exclusively by microUS-targeted and 4 by MRI-targeted biopsies. However, systematic biopsies still identified 22% of csPCa cases missed by both targeted approaches.

Conclusion: MicroUS, especially when combined with mpMRI, significantly enhances csPCa detection. This combined imaging approach may reduce the need for systematic biopsies. Further advancements in microUS technology could refine its diagnostic utility.

Introduction: We aim to critically assess Microultrasound (mUS) clinical performance in an outpatient setting, focusing on its ability to reduce unnecessary diagnostic procedures, potentially reshape prostate cancer (PCa) diagnostic protocols, and increase the ability to rule out clinically significant (Gleason Score ≥ 3 + 4) PCa (csPCa).

Materials and Methods: Between November 2018 and April 2022, we conducted a prospective study involving men who underwent mUS examination due to clinical symptoms, PSA elevation, or opportunistic early detection of PCa. Experienced urologists performed mUS assessments in an outpatient setting using the prostate risk identification using micro‐ultrasound (PRI‐MUS) protocol to identify lesions suspicious of csPCa (PRI‐MUS score ≥ 3). Men with negative mUS results were followed through consistent phone follow‐up calls and visits until October 2023 to assess their diagnostic and therapeutic pathways. Using Cox regression models adjusted for PSA levels, DRE results, age, and previous biopsy history, we calculated the hazard ratio (HR) for biopsy‐free (BFS), defined as the time from mUS to biopsy or last follow‐up, cancer‐free survival (CFS), and clinically significant cancer‐free survival (csCFS) within the cohort based on mUS results.

Results: Overall, 425 men were enrolled. The median (IQR) age was 66 (59–72) years, PSA levels were 5.7 (4.0–7.9) ng/mL, prostate volume was 44 (31.5–62.1) mL, and the median follow‐up was 39 months (27–53). mUS identified lesions suggesting csPCa in 201/425 (47.3%) men. Overall, mUS resulted negative in 224/425 (52.7%) men, of whom 207/224 (92.4%) did not undergo subsequent mpMRI, while 22/224 (9.8%) proceeded with mpMRI according to the referring physician's decision. The latter detected suspicious lesions in 12/22 cases (54.5%), but only 2/12 (16.7%) were confirmed by biopsy as csPCa. Among those with negative mUS results, 192/224 (85.7%) men avoided additional biopsies during follow‐up. Men with negative mUS results exhibited superior BFS (aHR: 0.17; p < 0.001), CFS (aHR:0.12; p < 0.001), and csCFS (aHR:0.09; p < 0.001) survival rates compared to their mUS‐positive counterparts.

Conclusions: Our findings suggest that mUS can potentially refine patient stratification and transform PCa screening and diagnostic protocols. Pending validation by other studies, a wider implementation of mUS could optimize resource allocation, minimize wastage, and reserve additional costly tests.

Background/Objectives: The diagnostic approach to prostate cancer (PCa) has evolved from systematic biopsies to imaging-guided strategies that improve detection of clinically significant PCa (csPCa) while reducing overdiagnosis. Multiparametric magnetic resonance imaging (mpMRI) has emerged as the gold standard for pre-biopsy evaluation, while micro-ultrasound (MicroUS) offers a promising alternative with real-time imaging capabilities.

Methods: We examined the principles, image interpretation frameworks (Prostate Imaging Reporting and Data System (PI-RADS) and Prostate Risk Identification using Micro UltraSound (PRI-MUS)), and clinical applications of mpMRI and MicroUS, comparing their diagnostic accuracy in biopsy-naïve patients, repeat biopsy scenarios, active surveillance, and staging.

Results: mpMRI improves csPCa detection, reduces unnecessary biopsies, and enhances risk stratification. Landmark studies such as PRECISION (Prostate Evaluation for Clinically Important Disease: Sampling Using Image Guidance or Not?) and PRIME (Prostate Imaging Using MRI±Contrast Enhancement) confirm its superiority over systematic biopsy. However, mpMRI remains resource-intensive, with limitations in accessibility and interpretation variability. Conversely, MicroUS, with its high-resolution real-time imaging, shows non-inferiority to mpMRI and potential advantages in magnetic resonance imaging (MRI)-ineligible patients. It improves lesion visualization and biopsy targeting, with ongoing trials such as OPTIMUM (Optimization of prostate biopsy—Micro-Ultrasound versus MRI) evaluating its standalone efficacy.

Conclusions: mpMRI and MicroUS are complementary modalities in PCa diagnosis. While mpMRI remains the preferred imaging standard, MicroUS offers an alternative, particularly in patients with MRI contraindications. Combining these techniques could enhance diagnostic accuracy, reduce unnecessary interventions, and refine active surveillance strategies. Future research should focus on integrating both modalities into standardized diagnostic pathways for a more individualized approach.

Background: Micro-ultrasound (micro-US; 29-MHz) offers real-time, high-resolution prostate imaging, but its stand-alone diagnostic accuracy remains uncertain. We synthesized prospective evidence to evaluate micro-US for classifying clinically significant prostate cancer (csPCa) using histopathology as the reference standard.

Methods: We searched PubMed, Embase, Scopus, and Web of Science (inception–20 May 2025) for prospective studies assessing micro-US as an index test on a diagnostic pathway. Data were pooled using random-effects models on logit-transformed sensitivity and specificity, with an HSROC representation and model diagnostics. Subgroup and meta-regression analyses explored heterogeneity, including threshold (PRI-MUS) and spectrum effects. Clinical utility was appraised using Fagan nomograms and a likelihood-ratio scatter. Small-study effects were evaluated with Deeks’ test.

Results: Five prospective studies met criteria. Pooled sensitivity was 0.84 (95% CI 0.65–0.94) and pooled specificity was 0.41 (95% CI 0.25–0.59), indicating moderate discrimination on HSROC. Secondary metrics were concordant (PLR 1.45, 95% CI 1.17–1.80; NLR 0.37, 95% CI 0.23–0.61; DOR 3.95, 95% CI 2.48–6.30). On a 25% pre-test probability, the Fagan nomogram showed modest shifts (~ 33% after a positive test; ~11% after a negative), supporting a triage/rule-out role. Heterogeneity was substantial and strongly influenced by threshold and clinical spectrum differences; subgroup and meta-regression suggested that spectrum-related factors were associated with lower specificity, whereas no covariate robustly altered sensitivity (exploratory given small k). Model checks were acceptable, and Deeks’ test showed no evidence of small-study effects (p ≈ 0.70).

Conclusion: As a stand-alone index test for csPCa classification, micro-US demonstrates high sensitivity but low specificity, yielding modest impact on post-test probability. These findings support micro-US as a complementary/triage (rule-out) adjunct, particularly when mpMRI is unavailable, contraindicated, or delayed, while highlighting the need for standardized PRI-MUS thresholds, reader training, and larger multicenter studies to refine specificity and clarify integration with MRI-based pathways.

Purpose: We compare the detection rates of clinically significant prostate cancer (csPCa) between cognitively targeted micro-ultrasound–guided biopsy (MB) and MRI/ultrasound fusion–guided biopsy (PFB) in men with MRI-visible lesions.

Materials and Methods: We retrospectively analyzed 1119 men who underwent MB (n = 767) or PFB (n = 352) between 2019 and 2022. Inverse probability of treatment weighting based on a logistic regression propensity score was applied to balance baseline characteristics between groups. Weighted logistic regression models were used to compare csPCa detection in the overall cohort and in subgroups of biopsy-naïve men and those with anterior lesions. A separate multivariable logistic regression was performed in the full cohort to identify independent predictors of csPCa. Concordance between biopsy and radical prostatectomy Gleason scores was also evaluated.

Results: After inverse probability of treatment weighting adjustment, csPCa detection with MB was higher than with PFB in combined sampling (45% vs 34%; odds ratio, 1.61; 95% CI: 1.23-2.11; P < .01). However, no significant difference was observed between techniques for targeted biopsies alone, both in the overall cohort and among biopsy-naïve men. In patients with anterior lesions, csPCa detection rates were also similar. In the full cohort multivariable model, MB and Prostate Imaging–Reporting and Data System 5 lesions were independently associated with csPCa. Gleason upgrading at prostatectomy was more frequent in the PFB group (38% vs 17%; P = .01).

Conclusions: While MB demonstrated higher csPCa detection in adjusted analyses, the benefit was not consistent across all settings. Further studies are warranted to determine whether this reflects a methodological advantage or context-dependent factors.

Background: The aim of this study was to evaluate the diagnostic outcomes of MRI-ultrasound fusion targeted biopsy in detecting clinically significant prostate cancer (csPCa) using either microUS technology or conventional ultrasound.

Methods: We identified a matched sample of 899 patients who underwent biopsy at a single institution between January 2017 and January 2023. A paired group of 470 patients was included. The proportion of cancers detected (any cancer and grade group (GG) ≥ 2) was compared between MRI-microUS and MRI-conventional US fusion biopsy groups.

Results: The overall incidence of GG ≥ 2 cancer was similar between MRI-microUS and MRI-conventional US fusion biopsy groups (53.6% vs. 55.3%, P > 0.05). In patients undergoing MRI-microUS fusion biopsy, detection of any cancer in SB was greater than TB (69.2% vs. 57.1%, P < 0.001), while GG ≥ 2 detection was similar between SB and TB (44.9% vs. 40.5%, P = 0.06). Moreover, detection of any cancer and GG ≥ 2 using TB were lower in the MRI-microUS fusion biopsy group. On multivariable analysis, age, race, biopsy status, PSA density, and PI-RADS score were significantly associated with detection of GG ≥ 2.

Conclusion: MicroUS-guided biopsy and conventional US-guided biopsy had similar rates of overall csPCa detection. Targeted biopsy using MRI-microUS fusion yielded lower overall and csPCa detection compared with MRI-conventional US fusion biopsy. MicroUS fusion biopsy is a reasonable alternative to conventional biopsy to detect csPCa.

Purpose: The limited resolution of standard transrectal ultrasound (TRUS) has made it difficult to perform biopsies of the prostate bed in cases of suspected local recurrence following radical prostatectomy. The aim of this study was to benchmark the performance of using high resolution micro‐ultrasound (microUS) in place of standard TRUS for performing post‐prostatectomy biopsies.

Materials and Methods: We conducted a retrospective review of pathology reports from January 2013 to October 2024, identifying patients who underwent biopsies of the prostate bed for suspected local recurrence after radical prostate. Sensitivity and specificity were compared for biopsies performed using standard TRUS. A biopsy was deemed diagnostic if it revealed prostate tissue (cancerous or benign) or non‐prostatic tissue when a previously suspicious lesion was no longer detectable on subsequent imaging. The ground truth for local recurrence was defined by biochemical recurrence (prostate‐specific antigen [PSA] ≥ 0.2 ng/mL in two consecutive measurements) accompanied by reproducible findings in the prostate bed on MRI and/or PET.

Results: Of the 24 patients included, 10 (42%) underwent microUS‐guided biopsy and 14 (58%) underwent TRUS‐guided biopsy. The median PSA levels at biopsy for the microUS and TRUS cohorts were 0.39 ng/mL (range 0.39–6.40) and 0.45 ng/mL (range 0.20–30.82), respectively. The median lesion sizes on MRI were 0.9 cm (IQR 0.7–1.8) for microUS and 2.5 cm (IQR 1.2–6) for TRUS. MicroUS demonstrated a sensitivity of 89% (95% CI: 52–100), compared with 43% (95% CI: 18–71) for TRUS. Specificity could not be reliably assessed, as only one recurrence‐negative patient was available in the microUS group and none in the TRUS group.

Conclusion: MicroUS‐guided transrectal biopsies appear to offer superior diagnostic performance in detecting local recurrences following radical prostatectomy compared to standard TRUS‐guided biopsy. Further study is needed to confirm our findings and to evaluate the performance of microUS‐guided biopsies independently of pre‐biopsy imaging results.

Background and Objective: Our objective was to evaluate the agreement between micro-ultrasound, MRI and pathological tumor and prostate volume.

Methods: Retrospective analysis of consecutive prostate cancer patients with MRI and micro-ultrasound diagnostic assessment who subsequently underwent radical prostatectomy. Tumor and prostate volume on micro-ultrasound and MRI imaging calculated by a dedicated software were compared to those of the prostatectomy specimen. Clinical, radiological, and pathological predictors of pathological tumor size were assessed.

Results: 65 men with a total of 104 lesions in the final pathology were included. Median micro-ultrasound tumor size was 1.05 ml (IQR 0.35–2.65). On MRI T2WI, DWI and ADC sequences median tumor volume was 0.73 ml (IQR 0.34–1.94), 0.94 ml (IQR 0.38–2.09) and 0.86 ml (IQR 0.42–1.58), respectively. The pathological median tumor size was 1.2 ml (IQR 0.2–3.9). On average, micro-ultrasound underestimated pathological tumor volume by 0.15 ml (P < 0.01) while DWI, the most precise MRI sequence underestimated tumor size by 0.26 ml (P < 0.01). The MRI and micro-ultrasound underestimated the pathological prostate volume by 6 ml (P < 0.01) and 3 ml (P = 0.47), respectively.

Conclusions: Both micro-ultrasound and MRI tend to slightly underestimate pathological tumor and prostate volume. Our study shows that both micro-ultrasound and MRI can be useful in the surgical planning although the underestimation of actual tumor size should be considered.

Objectives: This study compares the rate of detection of clinically significant prostate cancer (csPCa) using multiparametric MRI (mpMRI)-informed microultrasound-guided (microUS) biopsy to historical published data using mpMRI-ultrasound (mpMRI-US) fusion biopsy at the same institution.

Materials and methods: A single-center retrospective study of patients who underwent mpMRI-informed microultrasound-guided (microUS) biopsy was performed. Positive predictive value (PPV) of targeted lesions by PI-RADS and PRI-MUS (Prostate Risk Identification Using Microultrasound) was calculated and compared to published data using an mpMRI-US fusion platform.

Results: 169 subjects and 244 total lesions were identified by mpMRI. 44/244 (18.0%), 167/244 (68.4%), and 33/244 (13.5%) were PI-RADS 5, 4, and 3, respectively. 206/244 (84.4%) lesions seen on mpMRI were identified on microUS. 26 additional lesions were identified by microUS only. PCa was identified in 120/169 (71.0%) patients, and csPCa was identified in 70/169 (41.4%) by targeted microUS-guided biopsy of MRI lesions. Targeted biopsy of lesions seen only on microUS added three cases of csPCa (73/169, 43.2%). PPV of targeted PI-RADS 5, 4, and 3 lesions for all PCa and csPCa was 0.80, 0.61, and 0.39, and 0.64, 0.31, and 0.12, respectively. Findings were not significantly different compared to historical data using mpMRI-US fusion biopsy (p > 0.05). PPV for csPCa was 0.18 for mpMRI lesions when no correlate was identified by microUS, compared to 0.37 for lesions when a correlate was seen (p < 0.05).

Conclusions: This retrospective study demonstrates successful implementation of microUS-guided biopsy, with similar rates of identification of csPCa compared to historical data using mpMRI-US fusion.

Background and objective: High-resolution micro-ultrasound (microUS) is an advanced imaging tool. Our objective was to determine whether systematic microUS use for transrectal biopsy (TRBx) improves the detection rate for clinically significant prostate cancer (csPCa) in comparison to transperineal biopsy (TPBx) performed with magnetic resonance imaging (MRI)/conventional transrectal ultrasound (TRUS) fusion software.

Methods: We retrospectively analyzed data for men who underwent prostate biopsies, including those on active surveillance (AS). TRBx was performed under microUS guidance, while MRI/TRUS fusion was consistently used to guide TPBx. Patients were matched according to propensity score matching (PSM). The primary endpoint was comparison of the csPCa detection rate with the two approaches. Secondary endpoints included predictors of csPCa (International Society of Urological Pathology grade group ≥2, assessed via multivariable logistic regression) and complication rates.

Key findings and limitations: Overall, 1423 patients were enrolled. After applying PSM we identified an analytical cohort of 1094 men, 582 in the TRBx group and 512 in the TPBx group. There was no significant difference in the csPCa detection rate between the TRBx (45%) and TPBx (51%) groups (p = 0.07). Complications occurred in nine of 1094 patients (1%). On adjusted multivariable analysis, TPBx had a similar csPCa detection rate to TRBx (adjusted odds ratio [aOR] 1.26;p = 0.09). Predictors of csPCa detection were a positive family history (aOR 1.68; 95% confidence interval [CI] 1.20-2.35; p = 0.002); age (aOR 1.04, 95% CI 1.02-1.06; p < 0.001); positive digital rectal examination (aOR 2.35, 95% CI 1.70-3.25; p < 0.001); prostate-specific antigen density ≥0.15 ng/ml/cm3 (aOR 3.23, 95% CI 2.47-4.23; p < 0.001); and a Prostate Imaging-Reporting and Data System score ≥3 (aOR 2.46; 95% CI 1.83-3.32; p < 0.001). Limitations include the retrospective nature of the study, the risk of underestimating the complication rate, and the heterogeneity of biopsy indications.

Conclusions and clinical implications: TRBx using microUS alone showed a comparable csPCa detection rate to TPBx guided by MRI/TRUS fusion software. Given the better visualization and real-time detection of suspicious zones with microUS, the potential for improvement in the csPCa detection rate with greater integration of microUS in the TPBx setting warrants further investigation.

Introduction: Despite a negative magnetic resonance imaging (MRI), some patients may still harbor clinically significant prostate cancer (csPCa, Gleason grade group ≥2). High-resolution micro-ultrasound (microUS) is a novel imaging technology that could visualize csPCa that is missed by MRI.

Methods: This retrospective review included 1011 consecutive patients biopsied between September 2021 and July 2023 in Alberta, Canada. Among them were 103 biopsy-naive patients with negative MRI (Prostate Imaging Reporting & Data System [PI-RADS] ≤2) undergoing microUS-informed prostate biopsy (n=56) scored using Prostate Risk Identification Using Micro-ultrasound (PRI-MUS) or standard transrectal ultrasound prostate biopsy (n=47). The primary outcome was detection rate of csPCa stratified by biopsy technique and PRI-MUS score.

Results: MicroUS biopsy identified csPCa in 14/56 (25%) compared to standard biopsy in 8/47 (17%) (p=0.33). Patients with lesions PRI-MUS ≥3 had csPCa detected at a higher rate compared to patients with PRI-MUS ≤2 (42% vs. 16%, p=0.03). The csPCa detection rate was significantly different comparing patients with prostate-specific antigen (PSA) density <0.15 and PRI-MUS ≤2 compared to patients with PSA density ≥0.15 and PRI-MUS ≥3 (14% vs. 60%, p=0.02).

Conclusions: MicroUS may aid in the detection of csPCa for patients with negative MRI.

Background/Objectives: Prostate cancer is a prevalent malignancy often presenting without early symptoms. Advanced imaging technologies have revolutionized its diagnosis and management. This review discusses the principles, benefits, and clinical applications of multiparametric magnetic resonance imaging (mpMRI), micro-ultrasound (microUS), and prostate-specific membrane antigen positron emission tomography–computed tomography (PSMA PET/CT) in localized prostate cancer.

Methods: We conducted a comprehensive literature review of recent studies and guidelines on mpMRI, microUS, and PSMA PET/CT in prostate cancer diagnosis, focusing on their applications in biopsy-naïve patients, those with previous negative biopsies, and patients under active surveillance.

Results: MpMRI has demonstrated high sensitivity and negative predictive value in detecting clinically significant prostate cancer (csPCa). MicroUS, a newer technology, has shown promising results in early studies, with sensitivity and specificity comparable to mpMRI. PSMA PET/CT has emerged as a highly sensitive and specific imaging modality, particularly valuable for staging and detecting metastatic disease. All three technologies have been incorporated into urologic practice for prostate cancer diagnosis and management, with each offering unique advantages in different clinical scenarios.

Conclusions: Advanced imaging techniques, including mpMRI, microUS, and PSMA PET/CT, have significantly improved the accuracy of prostate cancer diagnosis, staging, and management. These technologies enable more precise targeting of suspicious lesions during biopsy and therapy planning. However, further research, especially randomized controlled trials, is needed to fully establish the optimal use and inclusion of these imaging modalities in various stages of prostate cancer care.

Background: MRI-guided focal laser ablation (FLA) is a promising treatment in localized prostate cancer (PCa). MRI-guided micro-US FLA shows potential for outpatient use, but its clinical application remains unexplored.

Purpose: To evaluate the safety, feasibility, and 12-month functional and oncologic outcomes of MRI-guided micro-US transperineal FLA in localized PCa and to assess the accuracy of micro-US in showing lesions depicted at MRI with Prostate Imaging Reporting and Data System (PI-RADS) score of 3 or higher. Materials and Methods This prospective, single-center observational study (July 2020 to June 2023) included participants with localized low- or intermediate-risk PCa and PI-RADS 3 or higher lesions (≤20 mm). Single- or multifiber FLA was performed at 1064 nm, guided by MRI-delineated image fusion. At 12 months, recurrence rates, complications, erectile function scores, and urinary symptom scores were assessed. Mann-Whitney U and Wilcoxon tests were used for comparisons.

Results: Fifty-five male participants (median age, 70 years; IQR, 62–74 years) with 58 lesions that were PI-RADS 3 or higher underwent transperineal FLA, with a 12-month follow-up for 33 participants. The median prostate-specific antigen level was 7.0 ng/mL (IQR, 5.6–9.0 ng/mL), 43 of 58 lesions (74%) had a Gleason score of 3 + 4, and 10 of 58 lesions (17%) had a Gleason score of 3 + 3. Single-fiber and multifiber FLA were used to treat 21 of 58 (36%) and 37 of 58 (64%) tumors, respectively. At micro-US, 53 of 58 (91%) tumors were successfully visualized. Multifiber FLA produced larger ablation volumes than did single-fiber treatment (median, 15 mL [IQR, 8–22 mL] vs 4.5 mL [IQR, 2.8–9.2 mL]; P < .001). At 12 months, biopsies in 35 treated tumors showed 17 recurrences (49%), including 13 in-field and four out-of-field recurrences. In-field recurrences occurred in 10 of 18 (56%) single-fiber and three of 17 (18%) multifiber cases. At 12 months, erectile function scores decreased compared with baseline (median International Index of Erectile Function score, 19 [IQR, 12–24] vs 21 [IQR, 15–24]; P < .001), whereas urinary function remained stable (median International Prostatic Symptom Score, 2 [IQR, 2–9] vs 6 [IQR, 3–11]; P = .72). One rectoprostatic fistula developed and required surgery.

Conclusion: Multifiber micro-US–guided FLA was safe and feasible, with 18% recurrence at 1-year follow-up.

Background: The diagnostic process for prostate cancer after a negative biopsy is challenging. This study compares the diagnostic accuracy of micro-ultrasound (mUS) with multiparametric magnetic resonance imaging (mpMRI) for such cases.

Methods: A retrospective cohort study was performed, targeting men with previous negative biopsies and using mUS and mpMRI to detect prostate cancer and clinically significant prostate cancer (csPCa).

Results: In our cohort of 1397 men, 304 had a history of negative biopsies. mUS was more sensitive than mpMRI, with better predictive value for negative results. Importantly, mUS was significantly associated with csPCa detection (adjusted odds ratio [aOR]: 6.58; 95% confidence interval [CI]: 1.15–37.8; p = 0.035).

Conclusions: mUS may be preferable for diagnosing prostate cancer in previously biopsy-negative patients. However, the retrospective design of this study at a single institution suggests that further research across multiple centers is warranted.

Objective: To determine the optimal number of cores needed during microultrasound-informed prostate biopsy for the detection of clinically significant prostate cancer (csPCa, defined as Gleason Grade Group ≥2).

Methods: A retrospective review of 1011 consecutive patients between September 2021 and July 2023 at our institution were identified; 536 underwent microultrasound biopsy and 475 underwent magnetic resonance imaging (MRI)/ultrasound (US) targeted biopsy. Lesions were given a Prostate Risk Identification using Microultrasound (PRI-MUS) score, with lesions PRI-MUS ≥3 targeted. MRI lesions were scored with Prostate Imaging-Reporting and Data System (PI-RADS) and lesions PI-RADS ≥3 were targeted. The primary outcome is the detection of csPCa stratified by number of cores.

Results: One hundred thirty-eight patients underwent targeted biopsies for microultrasound only lesions, 182 for microultrasound and MRI lesions and 426 underwent MRI/US for MRI lesions. The first targeted core detected 78.0% (46/59), 77.8% (63/81), and 78.8% (216/274) of csPCa for microultrasound, microultrasound+MRI, and MRI/US, respectively. Comparing first to third core, there was not a significant difference in overall detection of csPCa by microultrasound, though MRI/US was significantly different (28.4% vs 36.4% P = .12, 32.5% vs 41.8% P = .06, 42.5% vs 53.9% P < .001 for microultrasound, microultrasound+MRI, and MRI/US, respectively). PI-RADS 3 and PRI-MUS 3 lesions had lower first core detection rates compared to PI-RADS 5 and PRI-MUS 5 lesions (44.4% vs 85.4% P = .01, 65.2% vs 81.4% P = .14, 60% vs 83.1% P = .07 for microultrasound, microultrasound+MRI, and MRI/US, respectively).

Conclusion: A three-core targeted biopsy per microultrasound lesion improves detection rate of csPCa and should be considered to improve diagnostic accuracy.

Background: Prediction of extracapsular extension (ECE) is essential to achieve a balance between oncologic resection and neural tissue preservation. Microultrasound (MUS) is an attractive alternative to multiparametric magnetic resonance imaging (mpMRI) in the staging scenario.

Objective: To create a side-specific nomogram integrating clinicopathologic parameters and MUS findings to predict ipsilateral ECE and guide nerve sparing.

Design, setting, and participants: Prospective data were collected from consecutive patients who underwent robotic-assisted radical prostatectomy from June 2021 to May 2022 and had preoperative MUS and mpMRI. A total of 391 patients and 612 lobes were included in the analysis. Outcome measurements and statistical analysis ECE on surgical pathology was the primary outcome. Multivariate regression analyses were carried out to identify predictors for ECE. The resultant multivariable model's performance was visualized using the receiver-operating characteristic curve. A nomogram was developed based on the coefficients of the logit function for the MUS-based model. A decision curve analysis (DCA) was performed to assess clinical utility.

Results and limitations: The areas under the receiver-operating characteristic curve (AUCs) of the MUS-based model were 81.4% and 80.9% (95% confidence interval [CI] 75.6, 84.6) after internal validation. The AUC of the mpMRI-model was also 80.9% (95% CI 77.2, 85.7). The DCA demonstrated the net clinical benefit of the MUS-based nomogram and its superiority compared with MUS and MRI alone for detecting ECE. Limitations of our study included its sample size and moderate inter-reader agreement.

Conclusions: We developed a side-specific nomogram to predict ECE based on clinicopathologic variables and MUS findings. Its performance was comparable with that of a mpMRI-based model. External validation and prospective trials are required to corroborate our results.

Background: Active surveillance (AS) represents a standard of care of low-risk prostate cancer (PCa). However, the identification and monitoring of AS candidates remains challenging. Microultrasound (microUS) is a novel high-resolution imaging modality for transrectal ultrasonography (TRUS). We explored the impact of microUS TRUS and targeted biopsies in mpMRI-guided confirmatory biopsies.

Methods: Between October 2017 and September 2021, we prospectively enrolled 100 patients scheduled for MRI-guided confirmatory biopsy at 1 year from diagnosis of ISUP 1 PCa. TRUS was performed using the ExactVu microUS system; PRI-MUS protocol was applied to identify suspicious lesions (i.e., PRIMUS score ≥ 3). All patients received targeted biopsies of any identified microUS and mpMRI lesions and complementary systematic biopsies. The proportion of patients upgraded to clinically significant PCa (defined as ISUP ≥ 2 cancer; csPCa) at confirmatory biopsies was determined, and the diagnostic performance of microUS and mpMRI were compared.

Results: Ninety-two patients had a suspicious MRI lesion classified PI-RADS 3, 4, and 5 in respectively 28, 16, and 18 patients. MicroUS identified 82 patients with suspicious lesions, classified as PRI-MUS 3, 4, and 5 in respectively 20, 50, and 12 patients, while 18 individuals had no lesions. Thirty-four patients were upgraded to ISUP ≥ 2 cancer and excluded from AS. MicroUS and mpMRI showed a sensitivity of 94.1% and 100%, and an NPV of 88.9% and 100%, respectively, in detecting ISUP ≥ 2 patients. A microUS-mandated protocol would have avoided confirmatory biopsies in 18 patients with no PRI-MUS ≥ 3 lesions at the cost of missing four upgraded patients.

Conclusions: MicroUS and mpMRI represent valuable imaging modalities showing high sensitivity and NPV in detecting csPCa, thus allowing their use for event-triggered confirmatory biopsies in AS patients. MicroUS offers an alternative imaging modality to mpMRI for the identification and real-time targeting of suspicious lesions in AS patients.

Purpose: To develop and validate a micro-ultrasound risk score that predicts the likelihood of significant prostate cancer in the anterior zone.

Methods: Patients were enrolled from three expert institutions familiar with micro-ultrasound. The study was conducted in two phases. First, the PRI-MUS anterior score was developed by assessing selected prostate videos from patients who subsequently underwent radical prostatectomy. Second, seven urology readers with varying levels of experience in micro-ultrasound examination evaluated prostate loops according to the PRI-MUS anterior score. Each reader watched the videos and recorded the likelihood of the presence of significant cancer in the anterior part of the prostate in a three-point scale. The coherence among the readers was calculated using the Fleiss kappa and the Cronbach alpha.

Results: A total of 102 selected prostate scans were used to develop the risk assessment for anterior zone cancer in the prostate. The score comprised three categories: likely, equivocal, and unlikely. The median (IQR) sensitivity, specificity, positive predictive value, and negative predictive value for the seven readers were 72% (68-84), 68% (64-84), 75% (72-81), and 73% (71-80), respectively. The mean SD ROC AUC was 0.75 ± 2%, while the Fleiss kappa and the Cronbach alpha were 0.179 and 0.56, respectively.

Conclusion: Micro-ultrasound can detect cancerous lesions in the anterior part of the prostate. When combined with the PRI-MUS protocol to assess the peripheral part, it enables an assessment of the entire prostate gland. Pending external validation, the PRI-MUS anterior score developed in this study might be implemented in clinical practice.

Objective: To provide a summary of our initial experience and assess the impact of the Saline-Assisted Fascial Exposure (SAFE) technique on erectile function (EF), urinary continence, and oncological outcomes after Robot-Assisted Laparoscopic Radical Prostatectomy (RALP).

Patients and methods: From January 2021 to July 2022, we included patients with a baseline Sexual Health Inventory for Men (SHIM) score of ≥17 and a high probability of extracapsular extension (ECE), ranging from 21% to 73%, as per the Martini et al. nomogram. A propensity score matching was carried out at a ratio of 1:2 between patients who underwent RALP + SAFE (33) and RALP alone (66). The descriptive statistical analysis is presented. The SAFE technique was performed using two approaches, transrectal guided by micro-ultrasound or transperitoneal. Its principle entails a low-pressure injection of saline solution in the periprostatic fascia to achieve an atraumatic dissection of the neural hammock. Potency was defined as a SHIM score of ≥17 and continence as no pads per day.

Results: At follow-up intervals of 6, 13, 26, and 52 weeks, the SHIM score differed significantly between the two groups, favouring the RALP + SAFE (P = 0.01, P < 0.001, P < 0.001, and P = 0.01, respectively). These results remained significant when the mean SHIM score was assessed. As shown by the cumulative incidence curve, EF rates were higher in the RALP + SAFE compared to the RALP alone group (log-rank P < 0.001). The baseline SHIM and use of the SAFE technique were independent predictors of EF recovery.

Conclusions: The use of the SAFE technique led to better SHIM scores at 6, 13, 26, and 52 weeks after RALP in patients at high risk of ECE who underwent a partial NS procedure.

Introduction: High-resolution micro-ultrasound (micro-US) is a novel precise imaging modality that allows targeted prostate biopsies and multiparametric magnet resonance imaging (mpMRI) fusion. Its high resolution relying on a 29 MHz transducer allows real-time visualisation of prostate cancer lesions; this might overcome the inaccuracy of conventional MRI-US fusion biopsy strategies. We compared cancer detection rates in patients who underwent transrectal (TR-B) versus transperineal (TP-B) MR-micro-US fusion biopsy.

Materials and methods: 1:2 propensity score matching was performed in 322 consecutive procedures: 56 TR-B and 266 TP-B. All prostate biopsies were performed using ExactVuTM micro-US system with mpMRI image fusion. Clinically significant disease was defined as grade group ≥2. The primary objective was to evaluate the detection of clinically significant disease according to access route. The secondary outcomes were to compare the respective detection rates of random and targeted biopsies stratified per access route and to evaluate micro-US for its potential added value.

Results: 47 men undergoing TR-B and 88 undergoing TP-B were matched for age, PSA, clinical stage, prostate volume, PIRADS score, number of mpMRI-visible lesions and indication to biopsy. The detection rates of clinically significant and of any prostate cancer did not differ between the two groups (45% TR-B vs 42% TP-B; p = 0.8, and 57% TR-B vs 59% TP-B; p = 0.9, respectively). Detection rates also did not differ significantly between random (p = 0.4) and targeted biopsies (p = 0.7) stratified per access route. Micro-US targeted biopsy detected 36 MRI-invisible lesions in 33 patients; 19% of these lesions were positive for clinically significant disease. Overall, micro-US targeted biopsies upgraded 2% of patients to clinically significant disease that would have been missed otherwise.

Conclusions: MR-micro-US-fusion TR-B and TP-B have similar diagnostic yields in terms of detection rates of clinically significant prostate cancer. Micro-US targeted biopsy appears to have an additional diagnostic value over systematic and MRI-targeted biopsies.

Purpose: To evaluate the diagnostic accuracy of multiparametric magnetic resonance imaging (MRI)- and microultrasound (microUS)-guided targeted biopsy (TBx) in detecting prostate cancer (PCa) and clinically significant (cs) PCa among men with Prostate Imaging Reporting and Data System (PI-RADS 5) lesions and to compare this combined TBx (CTBx) strategy with CTBx plus systemic biopsy (SBx).

Methods: One hundred and thirty-six biopsy-naïve patients with PI-RADS 5 lesion at multiparametric MRI undergoing CTBx plus SBx were retrospectively evaluated. Analysis of diagnostic performance of microUS-TBx, MRI-TBx, CTBx, SBx and combined CTBx plus SBx was performed. Cost (downgrade, upgrade and biopsy core) to effectiveness (detection rate) was compared.

Results: CTBx achieved a comparable detection rate to CTBx plus SBx in diagnosis of PCa and csPCa (PCa: 78.7% [107/136] vs 79.4% [108/136]; csPCa: 67.6% [92/136] vs 67.6% [92/136]; p > 0.05) and outperformed SBx (PCa: 58.8% [80/136]; csPCa: 47.8% [65/136]; p < 0.001). Using CTB would have avoided 41.1% (56/136) unnecessary SBx, without missing any csPCa. The rate of any upgrading or csPCa upgrading was significantly higher by SBx than by CTBx [33/65 (50.8%) vs 17/65 (26.1%) and 20/65 (30.8%) vs 4/65 (6.15%), respectively, p < 0.05]. Considering csPCa detection rate, microUS showed high sensitivity and positive predictive value (94.6%, 87.9%, respectively), with lower specificity and negative predictive value (25.0% and 44.4%, respectively). At multivariable logistic regression models, positive microUS was identified as an independent predictor of csPCa (p = 0.024).

Conclusions: A combined microUS/MRI-TBx approach could be the ideal imaging tool for characterizing primary disease in PI-RADS five patients, allowing SBx to be avoided.

Introduction: New technologies to improve quality of prostate biopsies are appearing in clinical practice. We evaluate the performance of a micro-ultrasound device and the Prostate Risk Identification using MicroUltraSound (PRI-MUS) score in detecting clinically significant prostate cancer (csPCa).

Material and methods: We retrospectively reviewed data of 139 biopsy- naïve patients with suspicion of prostate cancer, who underwent diagnostic MRI and micro-ultrasonography (microUS), followed by transrectal prostatic biopsy (systematic ±targeted) under local anesthetic. The main objective was to evaluate the performance of the Prostate Risk Identification using MicroUltraSound (PRI-MUS) score in detecting csPCa, defined as International Society of Urological Pathology (ISUP) ≥2.

Results: Of all patients, 97 (70%) were found to have PCa, and 62 (45%) having csPCa. Among 100 patients with positive microUS (PRI-MUS score ≥3), 23 (23%) had ncsPCa and 57 (57%) were diagnosed with csPCa (ISUP ≥2); and in 39 patients with negative microUS, 12 (31%) were diagnosed with ncsPCa and 5 (13%) with csPCa. A PRI-MUS score ≥3 presented a sensitivity, specificity, positive predictive value and negative predictive value of 92%, 44%, 57% and 95%, respectively, for the detection of csPCa. The PRI-MUS score had higher areas under the curve than Prostate Imaging Reporting & Data System (PI-RADS) both for targeted (AUC 0.801 vs 0.733) and systematic + targeted (AUC 0.776 vs 0.694) biopsies for csPCa detection.

Conclusions: In our cohort, microUS performed well as a diagnostic tool through an easily implementable scale. MicroUS presented similar sensitivity and higher specificity than MRI in detecting csPCa. Further multicenter prospective studies may clarify its role in prostate cancer diagnosis.

Background: Multiparametric magnetic resonance imaging (mpMRI) is an invaluable diagnostic tool in the decision-making for prostate biopsies (PBx). However, a non-negligible proportion of patients with negative MRI (nMRI) may still harbour prostate cancer (PCa).

Objective: To assess whether microultrasound (micro-US) can help in substratifying the presence of PCa and clinically significant PCa (csPCa; ie, any Gleason score ≥7 PCa) in patients with nMRI despite a persistently high clinical suspicion of PCa. Design, setting, and participants A total of 125 biopsy-naïve patients who underwent micro-US–guided PBx with the ExactVu system for a persistently high suspicion of PCa despite nMRI were prospectively enrolled. Intervention The Prostate Risk Identification using micro-US (PRI-MUS) protocol was used to identify suspicious areas; PBx included targeted sampling of PRI-MUS ≥3 areas and systematic sampling.

Outcome measurements and statistical analysis: The primary endpoint was the assessment of micro-US diagnostic accuracy in detecting csPCa. Secondary endpoints included determining the proportion of patients with nMRI who may avoid PBx after micro-US or transrectal US, presence of cribriform and intraductal patterns on biopsy core examination, predictors of csPCa in patients presenting with nMRI, and comparing micro-US–targeted and systematic PBx in identifying csPCa.

Results and limitations: Considering csPCa detection rate, micro-US showed optimal sensitivity and negative predictive value (respectively, 97.1% and 96.4%), while specificity and positive predictive value were 29.7% and 34.0%, respectively. Twenty-eight (22.4%) patients with a negative micro-US examination could have avoided PBx with one (2.9%) missed csPCa. Cribriform and intraductal patterns were found in 14 (41.2%) and four (11.8%) of csPCa patients, respectively. In multivariable logistic regression models, positive micro-US, age, digital rectal examination, and prostate-specific antigen density ≥0.15 emerged as independent predictors of PCa. Targeted and systematic sampling identified 33 (97.1%) and 26 (76.5%) csPCa cases, respectively. The main limitation of the current study is represented by its retrospective single-centre nature on an operator-dependent technology.

Conclusions: Micro-US represents a valuable tool to rule out the presence of csPCa among patients with a persistent clinical suspicion despite nMRI.

Objectives: To compare the detection rate of clinically significant prostate cancer (csPC) and prostate cancer (PC) and to find out the diagnostic concordance between microultrasound (mUS), a high-resolution imaging system that can identify suspicious prostate lesions and biopsy them in real time, and multiparametric magnetic resonance imaging (mpMRI)-guided prostate fusion biopsies.

Methods: A prospective, multicenter, single-blind, single cohort study was conducted involving 80 patients with clinically suspected PC who underwent concomitant mpMRI-guided fusion prostate biopsy (Koelis System) and mUS-guided biopsy (ExactVu System)

Results: The detection rate of csPC was slightly higher for image-guided fusion biopsy (21.25% vs 18.75%), but this difference was not statistically significant (P = .453). There was also no significant difference in overall PC diagnosis (50% vs 51.25%, P = .897). The degree of agreement between the 2 diagnostic techniques for the detection of csPC as assessed by Cohen's Kappa concordance index was satisfactory κ ̂ = 0.676. The degree of International Society of Urological Pathology of targeted biopsies obtained from concordant lesions was also represented by satisfactory concordance with a Kappa index of κ ̂ = 0. 696.

Conclusion: mUS-guided biopsy is presented as an effective diagnostic method for the diagnosis of csPC compared to image-guided fusion biopsy. No differences are found in the detection rates of csPC and PC between the 2 strategies and satisfactory concordance is found in terms of histopathological findings.

Purpose: Micro-UltraSound (microUS) is a new imaging modality capable of identifying and targeting suspicious areas, which might further increase the diagnostic yield of prostate biopsy (PBx). Aim of this review is to provide insights into the usefulness of microUS for the sub-stratification of prostate cancer (PCa), clinically significant PCa (i.e., any Gleason score ≥ 7 PCa; csPCa) along with non-organ-confined disease in patients undergoing PBx.

Methods: A PubMed literature search was performed using keywords: prostate cancer diagnosis, prostate cancer diagnosis surveillance, systematic biopsy, target biopsy, micro-ultrasound, and prostate risk identification using micro-ultrasound.

Results: MicroUS could significantly improve multiparametric magnetic resonance imaging (mpMRI) findings by adding valuable anatomical and pathological information provided by real-time examination. Furthermore, microUS target biopsy could replace systematic biopsy in clinical practice by reducing the detection of clinically insignificant (ciPCa) and increasing that of csPCa. Finally, microUS may be useful in predicting the presence of non-organ confined PCa before radical prostatectomy and it could also be an effective add-on tool for patient monitoring within the active surveillance program.

Conclusion: MicroUS may represent an attractive step forward for the management of csPCa as a complementary or alternative tool to mpMRI. Nevertheless, further longitudinal studies are warranted, and the strength of the evidence is still suboptimal to provide clear recommendations for daily clinical practice.

Background and Objectives: Multiparametric magnetic resonance imaging (mpMRI) of the prostate and prostate-specific membrane antigen positron emission tomography (PSMA PET) are some examples of how the advancement of imaging techniques have revolutionized the diagnosis, staging, and consequently management of patients with prostate cancer (PCa). Although with less striking results, novel radiological modalities have also been proposed for bladder cancer (BCa) in recent years. Micro-ultrasound (MUS) is an imaging examination characterized by high real-time spatial resolution, recently introduced in the urological field. This article aimed to describe the current evidence regarding the application of MUS for the diagnosis and staging of PCa and BCa.

Materials and Methods: We designed a narrative review. A comprehensive search in the MEDLINE, Scopus, and Cochrane Library databases was performed. Articles in English-language and published until July 2022 were deemed eligible. Retrospective and prospective primary clinical studies, as well as meta-analyses, were included.

Results: MUS-guided prostate biopsy showed high sensitivity (0.91, 95% CI, 0.79–0.97) in the diagnosis of clinically significant PCa (csPCa). It was associated with a higher detection rate of csPCa than a systematic biopsy (1.18, 95% CI 0.83–1.68). No significant difference was found between MUS and mpMRI-guided biopsy in the total detection of PCa (p = 0.89) and in the detection of Grade Groups ≥ 2 (p = 0.92). The use of MUS to distinguish between non-muscle-invasive and muscle-invasive BCa was described, highlighting an up-staging with MUS only in a minority of cases (28.6%).

Conclusions: Promising findings have emerged regarding the feasibility and accuracy of MUS in the diagnosis and staging of PCa and BCa. However, the available evidence is limited and should be considered preliminary.

Objective: To determine the detection of clinically significant prostate cancer (csPCa) index lesion using high resolution transrectal micro-ultrasound (MicroUS) applying PRI-MUS (Prostate Risk Identification using Micro Ultrasound) score v1.0.

Methods: Men who underwent radical prostatectomy following biopsy and MicroUS assessment were included. MicroUS dynamic cine loops of these patients were retrospectively reviewed by an experienced radiologist. The radiologist was aware that patients had undergone radical prostatectomy but was blinded to pathological data. Suspicious sites were assigned a PRI-MUS score. Radical prostatectomy specimens were examined with the quarter mount technique. Detection rate of csPCa index lesion [Grade Group (GG) ≥2] by MicroUS was assessed at a patient level.

Results: Twenty-five participants were included in the analysis. The median age was 65.5 years (range 56-74). Median PSA was 6.45 ng/dL (range 2-31.72). Two of 25 patients did not have csPCa (GG1 disease) on radical prostatectomy. MicroUS visualized 20/23 (87%) of the csPCa index lesions [median length 9 mm (range 1.5- 28.5)]. All identified lesions were categorized PRIMUS score 4 or 5. The 3 missed index lesions were in the transition zone [median length 10.5 mm (range 4.5-22.5)]. MicroUS missed 11 non index csPCa in 9 participants [median length 1.5 mm (range 1.5-10.5)]. Of these, 8 were GG2, 2 GG3 and 1 GG5. MicroUS identified the csPCa index lesion in all 9 of these men.

Conclusion: MicroUS showed the high sensitivity (87%) in detecting index lesions in the prostate gland and identified 100% of index lesions in the peripheral zone.

Objective: Micro-ultrasound is an imaging modality used to visualize and target prostate cancer during transrectal or transperineal biopsy. We evaluated the effectiveness of a micro-ultrasound training program and estimated the learning curve for prostate biopsy.

Methods: A training program registry was assessed for the rate of clinically significant prostate cancer (csPCa, grade group ≥ 2), negative predictive value, and specificity at each stage of the program. Nine metrics of biopsy quality were evaluated in 4 stages for each practitioner. Non-linear fitting and logistic regression models were used to evaluate the time-course of these metrics over training.

Results: Thirteen practitioners from 8 institutions completed stages 1 to 3 of the program, and 9 completed all 4 stages. Over 1190 micro-ultrasound biopsy procedures were performed. Detection of csPCa increased from 40% to 57% from stage 1 to stage 4 (P < 0.01). Stage 4 “expert” level was independently associated with higher detection of csPCa when correcting for overall risk factors (OR 1.95; P = 0.03). Limitations include the retrospective analysis and variation in biopsy protocols.

Conclusion: The micro-ultrasound training program was effective in improving biopsy quality and rate of csPCa detection. The presented learning curve provides an initial guide for acquiring expertise with real-time micro-ultrasound image-guided biopsy.

Background: Multiparametric MRI has led to increased detection of clinically significant prostate cancer (csPCa). Micro-US is being investigated for csPCa detection.

Purpose: To compare multiparametric MRI and micro-US in detecting csPCa (grade group ≥2) and to determine the proportion of MRI nodules visible at micro-US for real-time targeted biopsy.

Materials and methods: This prospective, single-center trial enrolled biopsy-naive men with suspected prostate cancer (PCa) between May 2019 and September 2020. All patients underwent multiparametric MRI followed by micro-US; findings at both were interpreted in a blinded fashion, followed by targeted biopsy and nontargeted systematic biopsy using micro-US. Proportions were compared using the exact McNemar test. The differences in proportions were calculated.

Results: Ninety-four men (median age, 61 years; IQR, 57–68 years) were included. MRI- and micro-US–targeted biopsy depicted csPCa in 37 (39%) and 33 (35%) of the 94 men, respectively (P = .22); clinically insignificant PCa in 14 (15%) and 15 (16%) (P > .99); and cribriform and/or intraductal PCa in 14 (15%) and 13 (14%) (P > .99). The MRI- plus micro-US–targeted biopsy pathway depicted csPCa in 38 of the 94 (40%) men. The addition of nontargeted systematic biopsy to MRI- plus micro-US–targeted biopsy did not enable identification of any additional men with csPCa but did help identify nine additional men with clinically insignificant PCa (P = .04). Biopsy was avoided in 32 of the 94 men (34%) with MRI and nine of the 94 men (10%) with micro-US (P < .001). Among 93 MRI targets, 62 (67%) were prospectively visible at micro-US.

Conclusion: MRI and micro-US showed similar rates of prostate cancer detection, but more biopsies were avoided with the MRI pathway than with micro-US, with no benefit of adding nontargeted systematic biopsy to the MRI- plus micro-US–targeted biopsy pathway. Most MRI lesions were prospectively visible at micro-US, allowing real-time targeted biopsy.

Purpose: of review Multiparametric magnetic resonance imaging (mpMRI) has fundamentally changed how intraprostatic lesions are visualized, serving as a highly sensitive means for detecting clinically significant prostate cancer (csPCa) via image-targeted biopsy. However, limitations associated with mpMRI have led to the development of new imaging technologies with the goal of better characterizing intraprostatic disease burden to more accurately guide treatment planning and surveillance for prostate cancer focal therapy. Herein, we review several novel imaging modalities with an emphasis on clinical data reported within the past two years. Recent findings 7T MRI, artificial intelligence applied to mpMRI, positron emission tomography combined with either computerized tomography or MRI, contrast-enhanced ultrasound, and micro-ultrasound are novel imaging modalities with the potential to further improve intraprostatic lesion localization for applications in focal therapy for prostate cancer. Many of these technologies have demonstrated equivalent or favorable diagnostic accuracy compared to contemporary mpMRI for identifying csPCa and some have even shown improved capabilities to define lesion borders, to provide volumetric estimates of lesions, and to assess the adequacy of focal ablation of planned treatment zones.

Summary: Novel imaging modalities with capabilities to better characterize intraprostatic lesions have the potential to improve accuracy in treatment planning, real-time assessment of the ablation zone, and posttreatment surveillance; however, many of these technologies require further validation to determine their clinical utility.

Purpose: The diagnosis of prostate cancer (PCa) still relies on the performance of both targeted (TB) and systematic biopsies (SB). Micro-ultrasound (mUS)-guided biopsies demonstrated a high sensitivity in detecting clinically significant prostate cancer (csPCa), which could be comparable to that of magnetic resonance imaging (MRI)-TB, but their added value has not been compared to SB yet.

Methods: We conducted a systematic review and meta-analysis, based on Medline, EMBASE, Scopus, and Web of Science, in accordance with PRISMA guidelines, to compare mUS-guided biopsies to SB.

Results: Based on the literature search of 2957 articles, 15 met the inclusion criteria (2967 patients). Most patients underwent mUS-guided biopsies, followed by MRI-TB and SB. Respectively 5 (n = 670) and 4 (n = 467) studies, providing raw data on SB, were included in a random-effect meta-analysis of the detection rate of csPCa, i.e. Gleason Grade Group (GGG) ≥ 2 or non-csPCa (GGG = 1). Overall, PCa was detected in 56-71% of men, with 31.3-49% having csPCa and 17-25.4% having non-csPCa. Regarding csPCa, mUS-guided biopsies identified 196 and SB 169 cases (Detection Ratio (DR): 1.18, 95% CI 0.83-1.68, I2 = 69%), favoring mUS-guided biopsies; regarding non-csPCa, mUS-guided biopsies identified 62 and SB 115 cases (DR: 0.55, 95% CI 0.41-0.73, I2 = 0%), also favoring mUS-guided biopsies by decreasing unnecessary diagnosis.

Conclusion: Micro-ultrasound-guided biopsies compared favorably with SB for the detection of csPCa and detected fewer non-csPCa than SB. Prospective trials are awaited to confirm the interest of adding mUS-guided biopsies to MRI-TB to optimize csPCa detection without increasing overdiagnosis of non-csPCa.

Introduction: High-resolution micro-ultrasound (microUS) is a novel imaging technique that may visualize clinically significant prostate cancer (csPCa), including those missed by magnetic resonance imaging (MRI ), in real time during prostate biopsy.

Methods: From September 2021 to January 2022, 75 consecutive biopsy-naive men were entered into an observational cohort. All men underwent an MRI /microUS fusion prostate biopsy, completed by a single surgeon using the ExactVU device. At time of biopsy, each biopsy core was given a Prostate Risk Identification using MicroUS (PRI-MUS) score. Anonymized data were entered into a RED Cap database. Cancer detection stratified by Prostate Imaging-Reporting & Data System (PI-RADS ) and PRI-MUS score, and imaging modality was captured. Our primary outcome was the detection rate of csPCa in microUS-informed systematic biopsy cores, taken outside MRI-visible lesions, during MRI /microUS fusion prostate biopsy.

Results: A median of three MRI-targeted and 12 microUS-informed systematic cores were taken per patient. MRI /microUS biopsy detected PCa in 84%, with csPCa detected in 52%. Of the 900 microUS-informed systematic cores, 105 cores were PRI-MUS ≥3 and 795 cores were PRI-MUS ≤2. csPCa was detected in 35% of the PRI-MUS ≥3 cores compared to 10% of the PRI-MUS ≤2 cores (p<0.0001). Detection of csPCa varied by core type: 8% of patients were diagnosed by MRI-targeted cores only, 38% were diagnosed by microUS-informed systematic cores only, and 54% were diagnosed by both.

Conclusions: MicroUS-informed systematic biopsy may be a useful adjunct to MRI, with PRI-MUS ≥3 systematic cores having a 3.5-fold increased risk of csPCa compared to PRI-MUS ≤2 cores.

Background: To compare the detection rate of microultrasound with that of multiparametric magnetic resonance imaging targeted biopsy (mpMRI-TB) for prostate cancer (PCa) diagnosis.

Methods: The studies on microultrasound prostate biopsy for PCa diagnosis were searched in PubMed, Cochrane library, and EMBASE databases from inception to April 2021. We performed a systematic review and cumulative meta-analysis based on search results using Software Rev-Man 5.3.

Results: A total of 11 studies involving 1081 patients were included. The meta-analysis showed that no significant difference was found between microultrasound and mpMRI-TB in the total detection of PCa (odds ratio [OR]: 1.01, 95% confidence interval [CI]: 0.85-1.21, p = 0.89), of grading groups (GGs) = 1 (OR: 0.92, 95% CI: 0.68-1.25, p = 0.59), of GGs ≥2 (OR:1.01, 95% CI: 0.83-1.22, p = 0.92), and of GGs ≥3 (OR: 1.31, 95% CI: 0.95-1.81, p = 0.10).

Conclusions: Microultrasound-guided prostate biopsy provides detection rates for PCa diagnosis comparable with those of the mpMRI-TB, which is expected to challenge mpMRI-TB in the diagnosis of PCa.

Objective: To compare the efficacy of multiparametric magnetic resonance imaging (mpMRI)-directed and micro-ultrasonography (micro-US)-directed biopsy for detecting clinically significant (Grade Group >1) prostate cancer (csPCa).

Materials and Methods: A total of 203 patients were prospectively enrolled at three institutions across Germany and Austria in the period from January 2019 to December 2019. During each biopsy, the urologist was blinded to the mpMRI report until after the micro-US targets had been assessed. After unblinding, targets were then sampled using software-assisted fusion, followed by systematic samples. The primary outcome measure was non-inferiority of micro-US to detect csPCa, with a detection ratio of at least 80% that of mpMRI.

Results: A total of 79 csPCa cases were detected overall (39%). Micro-US-targeted biopsy detected 58/79 cases (73%), while mpMRI-targeted biopsy detected 60/79 (76%) and non-targeted (completion sampling) samples detected 45/79 cases (57%). mpMRI-targeted samples alone detected 7/79 (9%) csPCa cases which were missed by micro-US-targeted and non-targeted samples. Three of these seven were anterior lesions with 2/7 in the transition zone. Micro-US-targeted samples alone detected 5/79 (6%) and completion sampling alone detected 4/79 cases (5%). Micro-US was non-inferior to mpMRI and detected 97% of the csPCa cases detected by mpMRI-targeted biopsy (95% CI 80–116%; P = 0.023).

Conclusions: This is the first multicentre prospective study comparing micro-US-targeted biopsy with mpMRI-targeted biopsy. The study provides further evidence that micro-US can reliably detect cancer lesions and suggests that micro-US biopsy might be as effective as mpMRI for detection of csPCA. This result has significant implications for increasing accessibility, reducing costs and expediting diagnosis.

Purpose: Micro-ultrasound is a novel high resolution ultrasound technology aiming to improve prostate imaging and, consequently, the diagnostic accuracy of ultrasound-guided prostate biopsy. Micro-ultrasound–guided prostate biopsy may present comparable detection rates to the standard of care multiparametric magnetic resonance imaging-targeted prostate biopsy for the diagnosis of clinically significant prostate cancer. We aimed to compare the detection rate of micro-ultrasound vs multiparametric magnetic resonance imaging-targeted prostate biopsy for prostate cancer diagnosis.

Materials and Methods: We performed a systematic review and meta-analysis of diagnostic accuracy studies comparing micro-ultrasound–guided prostate biopsy to multiparametric magnetic resonance imaging-targeted prostate biopsy as a reference standard test (PROSPERO ID: CRD42020198326). Records were identified by searching in PubMed®, Scopus® and Cochrane Library databases, as well as in potential sources of gray literature until November 30th, 2020.

Results: We included 18 studies in the qualitative and 13 in the quantitative synthesis. In the quantitative synthesis, 1,125 participants received micro-ultrasound–guided followed by multiparametric magnetic resonance imaging-targeted and systematic prostate biopsy. Micro-ultrasound and multiparametric magnetic resonance imaging-targeted prostate biopsies displayed similar detection rates across all prostate cancer grades. The pooled detection ratio for International Society of Urological Pathology Grade Group ≥2 prostate cancer was 1.05 (95% CI 0.93–1.19, I2=0%), 1.25 (95% CI 0.95–1.64, I2=0%) for Grade Group ≥3 and 0.94 (95% CI 0.73–1.22, I2=0%) for clinically insignificant (Grade Group 1) prostate cancer. The overall detection ratio for prostate cancer was 0.99 (95% CI 0.89–1.11, I2=0%).

Conclusions: Micro-ultrasound–guided prostate biopsy provides comparable detection rates for prostate cancer diagnosis with the multiparametric magnetic resonance imaging-guided prostate biopsy. Therefore, it could be considered as an attractive alternative to multiparametric magnetic resonance imaging-targeted prostate biopsy. Nevertheless, high quality randomized trials are warranted to corroborate our findings.

Background: Micro-ultrasound (microUS) is a novel ultrasound-based imaging modality which has demonstrated the ability to visualize prostate cancer. Multiparametric MRI/ultrasound (mpMRI/US) fusion has recognized advantages for the performance of prostate biopsy, however, it encompasses additional cost, time and technical expertise to performing prostate biopsy in comparison to conventional trans-rectal ultrasound biopsy. MicroUS may simplify and optimize this pathway.

Methods: OPTIMUM is a 3-arm randomized controlled trial comparing microUS guided biopsy with MRI/US fusion and MRI/MicroUS "contour-less" fusion. This trial will investigate whether microUS alone, or in combination with mpMRI, provides effective guidance during prostate biopsy for the detection of clinically significant prostate cancer (csPCa) for biopsy naïve subjects. 1200 subjects will be randomized. The economic impact will be evaluated.

Results: The rate of csPCa (defined as Grade Group 2 and above) in each arm will be compared. The primary hypothesis is non-inferiority of csPCa rate between the MRI/US fusion arm and the microUS-only arm (including the blinded microUS-only portion of the MRI/MicroUS arm). As a secondary objective, the csPCa rate between MRI/MicroUS fusion and MRI/US fusion arms will also be compared. Other secondary objectives include the increase in rate of patients diagnosed with csPCa due to each type of sample (mpMRI targeted, microUS targeted, systematic), the negative predictive value of each imaging modality, and a health economic analysis of the procedures in each arm.

Conclusions: OPTIMUM will determine whether microUS can be used as an alternative to MRI/US fusion biopsy. The trial will also evaluate the efficacy of the simplified "contour-less" MRI/MicroUS fusion procedure. The adoption of the microUS technique will increase the proportion of men who can benefit from modern imaging-centric diagnostic strategies, and may help reduce variability, complexity, waiting time and cost within the diagnostic pathway.

Introduction: Magnetic Resonance Imaging (MRI) has emerged as the most accurate diagnostic tool, showing a high sensitivity in the diagnosis of clinically significant prostate cancer (csCaP). However only a minority of patients with a PI-RADS 3 lesion at multiparametric magnetic resonance imaging (MRI) are diagnosed with csCaP. The aim of the current study was to assess whether high resolution micro-ultrasound (microUS) could help in sub-stratifying the risk of csCaP in this specific population.

Material and methods: We retrospectively analyzed the records of 111 consecutive patients scheduled for a prostate biopsy with at least 1 PI-RADS 3 lesions at MRI. We excluded patients with a PIRADS >3 lesion, even if they had a coexisting PIRADS 3 lesions. MicroUS was performed in all patients before prostate biopsy by an operator blind to MRI results. The Prostate Risk Identification using MicroUS (PRI-MUS) protocol was used to assess the risk of CaP and csCaP. All patients received both targeted and systematic biopsies. The primary endpoint was to determine the diagnostic accuracy of microUS in detection of csCaP in patients with a PI-RADS 3 lesion at MRI. Specifically, sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of microUS were determined. Multivariable logistic regression models (MLRMs) were fitted to identify predictors of CaP. The diagnostic accuracy was reported as area under the receiver operator characteristic (ROC) curve.

Results: Overall, 43 patients (38.7%) harboured CaP and 22 (20%) csCaP. MicroUS showed a high sensitivity and negative predictive value (100%), while its specificity and positive predictive value were 33.7% and 27.2%, respectively. Among patients without lesions at microUS, 25 (83.3%) did not harbour CaP, while 5 (16.7%) patients were diagnosed with a Gleason score 6 CaP, with no patients harbouring csCaP. Using microUS, the csCaP detection would have remained 100%, while reducing the detection of insignificant CaP of a 23.8% extent (n = 5). In MLRMs, lesion identified at microUS and continuously-coded PSAd were independent predictors of CaP. The accuracy of a model including PRI-MUS score, digital rectal examination (DRE), PSA density, age and family history was 0.744 (95% CI: 0.645 – 0.843).

Conclusion: In our single-institutional retrospective study, microUS was potentially capable to stratify the presence of CaP in patients with an equivocal MRI. Further prospective studies on larger populations are needed to validate our results.

Objectives: To evaluate the ability of high-frequency (29 MHz) transrectal micro-ultrasound (microUS) as a second-look examination after biparametric MRI (bp-MRI) and to reidentify focal lesions seen on diagnostic MRI and to detect new ones

Methods: A total of 118 consecutive men (mean age, 66 ± 13 [SD] years; range, 49–93 years) with a mean prostate-specific antigen level of 11 ± 19 (SD) ng/mL (range, 2–200 ng/mL) and at least one focal lesion (MRI+) with a score > 2 on bp-MRI were included. Of these, 79/118 (66.9%) were biopsy-naïve and 102/118 (86.5%) had non-suspicious rectal examination. All patients had MRI-directed microUS-guided biopsy using a 29-MHz transducer. All lesions visible on micro-ultrasound (microUS+) were targeted without image fusion, which was only used for MRI+/microUS− lesions. Significant prostate cancer (sPCa) was defined by a Gleason score ≥ 7 or a maximum cancer core length > 3 mm.

Results: A total of 144 focal prostatic lesions were analyzed, including 114 (114/144, 79.2%) MRI+/microUS+ lesions, 13 MRI+/microUS− lesions (13/144, 9%), and 17 MRI−/microUS+ lesions (17/144, 11.8%). Significant PCa was detected in 70 MRI+/microUS+ lesions (70/114, 61.4%), in no MRI+/microUS− lesion (0/13, 0%), and in 4 MRI-/microUS+ lesions (4/17, 23.5%). The sensitivity and specificity of microUS on a per-patient and a per-lesion basis were 100% (95% CI, 84.9–100%) and 22.8% (95% CI, 12.5–35.8%) and 100% (95% CI, 85.1–100%) and 22.6% (95% CI, 12.3–36.2%), respectively.

Conclusion: MicroUS, as a second-look examination, may show promise to localize targets detected on bp-MRI.

Introduction: High-resolution micro-ultrasound has the capability of imaging prostate cancer based on detecting alterations in ductal anatomy, analogous to multiparametric magnetic resonance imaging (mpMRI). This technology has the potential advantages of relatively low cost, simplicity, and accessibility compared to mpMRI. This multicenter, prospective registry aims to compare the sensitivity, specificity, negative predictive value (NPV), and positive predictive value (PPV) of mpMRI with high-resolution micro-ultrasound imaging for the detection of clinically significant prostate cancer.

Methods: We included 1040 subjects at 11 sites in seven countries who had prior mpMRI and underwent ExactVu micro-ultrasound-guided biopsy. Biopsies were taken from both mpMRI targets (Prostate Imaging-Reporting and Data System [PI-RADS] >3 and micro-ultrasound targets (Prostate Risk Identification using Micro-ultrasound [PRIMUS] >3). Systematic biopsies (up to 14 cores) were also performed. Various strategies were used for mpMRI target sampling, including cognitive fusion with micro-ultrasound, separate software-fusion systems, and software-fusion using the micro-ultrasound FusionVu system. Clinically significant cancer was those with Gleason grade group ≥2.

Results: Overall, 39.5% were positive for clinically significant prostate cancer. Micro-ultrasound and mpMRI sensitivity was 94% vs. 90%, respectively (p=0.03), and NPV was 85% vs. 77%, respectively. Specificities of micro-ultrasound and MRI were both 22%, with similar PPV (44% vs. 43%). This represents the initial experience with the technology at most of the participating sites and, therefore, incorporates a learning curve. Number of cores, diagnostic strategy, blinding to MRI results, and experience varied between sites.

Conclusions: In this initial multicenter registry, micro-ultrasound had comparable or higher sensitivity for clinically significant prostate cancer compared to mpMRI, with similar specificity. Micro-ultrasound is a low-cost, single-session option for prostate screening and targeted biopsy. Further larger-scale studies are required for validation of these findings.

Objectives: To evaluate the ability of high-frequency (29 MHz) transrectal micro-ultrasound (microUS) as a second-look examination after biparametric MRI (bp-MRI) and to reidentify focal lesions seen on diagnostic MRI and to detect new ones.

Methods: A total of 118 consecutive men (mean age, 66 ± 13 [SD] years; range, 49–93 years) with a mean prostate-specific antigen level of 11 ± 19 (SD) ng/mL (range, 2–200 ng/mL) and at least one focal lesion (MRI+) with a score > 2 on bp-MRI were included. Of these, 79/118 (66.9%) were biopsy-naïve and 102/118 (86.5%) had non-suspicious rectal examination. All patients had MRI-directed microUS-guided biopsy using a 29-MHz transducer. All lesions visible on micro-ultrasound (microUS+) were targeted without image fusion, which was only used for MRI+/microUS− lesions. Significant prostate cancer (sPCa) was defined by a Gleason score ≥ 7 or a maximum cancer core length > 3 mm.

Results: A total of 144 focal prostatic lesions were analyzed, including 114 (114/144, 79.2%) MRI+/microUS+ lesions, 13 MRI+/microUS− lesions (13/144, 9%), and 17 MRI−/microUS+ lesions (17/144, 11.8%). Significant PCa was detected in 70 MRI+/microUS+ lesions (70/114, 61.4%), in no MRI+/microUS− lesion (0/13, 0%), and in 4 MRI-/microUS+ lesions (4/17, 23.5%). The sensitivity and specificity of microUS on a per-patient and a per-lesion basis were 100% (95% CI, 84.9–100%) and 22.8% (95% CI, 12.5–35.8%) and 100% (95% CI, 85.1–100%) and 22.6% (95% CI, 12.3–36.2%), respectively.

Conclusion: MicroUS, as a second-look examination, may show promise to localize targets detected on bp-MRI.

Background: Although multiparametric magnetic resonance imaging (mpMRI) revolutionized the implementation of prostate biopsies, a considerable amount of clinically significant prostate cancer (csPCa) is missed when performing mpMRI-targeted biopsies only. Microultrasound (micro-US) is a new modality that allows real-time targeting of suspicious regions.

Objective: To evaluate micro-US of the prostate with real-time targeting of suspicious regions in patients suspected to have prostate cancer (PCa). Design, setting, and participants We examined 159 patients with prior mpMRI and suspicion of PCa with micro-US in the period from February to December 2018. Micro-US lesions were documented according to the prostate risk identification for micro-US (PRI-MUS) protocol, and were blinded to the mpMRI results and targeted independently of the mpMRI lesions.

Outcome measurements and statistical analysis: The main outcomes were cancer detection rate, additional detection of csPCa, and International Society of Urological Pathology (ISUP) grade group upgrading via micro-US. Results and limitations PCa was found in 113/159 (71%) men, with 49% (78/159) having clinically significant cancer (csPCa; ISUP ≥ 2). Micro-US–targeted biopsies resulted in a higher ISUP grade group than the nontargeted biopsies in 26% (42/159), compared with both nontargeted and MRI-targeted biopsies in 16% (26/159). In 17% (27/159) of patients, targeted mpMRI–guided biopsy was negative with cancer identified in the micro-US–guided biopsy, of whom 20 had csPCa. The comparison with only MRI-positive patients is the main limitation of this analysis.

Conclusions: Our data show an added benefit of micro-US in addition to mpMRI-targeted biopsies in a population of men at risk of PCa. A novel biopsy protocol with solely targeted biopsy with micro-US and mpMRI seems possible, replacing conventional ultrasound and omitting standard systematic biopsies.

Background: Multiparametric magnetic resonance imaging (MRI) represents the gold standard for the diagnosis of clinically significant prostate cancer (csPCa). The search for alternative diagnostic techniques is still ongoing.

Objective: To determine the accuracy of microultrasound (microUS) for the diagnosis of csPCa within prospectively collected cohort of patients with a suspicion of prostate cancer (PCa) according to MRI.

Design, setting, and participants: A total of 320 consecutive patients with at least one Prostate Imaging Reporting and Data System (PIRADS) ≥3 lesion according to MRI were prospectively enrolled. Intervention All patients received microUS before prostate biopsy using the ExactVu system; the Prostate Risk Identification using microUS (PRI-MUS) protocol was used to identify targets. The urologists were blinded to MRI results until after the microUS targeting was completed. All patients received both targeted (based on either microUS or MRI findings) and randomized biopsies. Outcome measurements and statistical analysis The sensitivity and specificity of microUS to determine the presence of csPCa (defined as at least one core with a Gleason score ≥7 PCa) were determined. Multivariable logistic regression analysis was fitted to determine the predictors of csPCa.

Results and limitations: Clinically significant PCa was diagnosed in 116 (36.3%) patients. The sensitivity and negative predictive value of microUS for csPCa diagnosis were 89.7% and 81.5%, while specificity and positive predictive value were 26.0% and 40.8%, respectively. A combination of microUS-targeted and randomized biopsies would allow diagnosing the same proportion of csPCa as that diagnosed by an approach combining MRI-targeted and randomized biopsies (n = 113; 97.4%), with only three (2.6%) csPCa cases diagnosed by a microUS-targeted and three (2.6%) by an MRI-targeted approach. In a logistic regression model, an increasing PRI-MUS score was an independent predictor of csPCa (p ≤ 0.005). The main limitation of the current study is represented by the fact that all patients had suspicious MRI.

Conclusions: Microultrasound is a promising imaging modality for targeted prostate biopsies. Our results suggest that a microUS-based biopsy strategy may be capable of diagnosing the great majority of cancers, while missing only few patients with csPCa.

Background: Prostate cancer is a frequently diagnosed malignant solid tumor in men. The accuracy of diagnosis is becoming increasingly important. This meta-analysis evaluated the accuracy of micro-ultrasound in the diagnosis of clinically significant prostate cancer.

Methods: We searched PubMed, Embase, Web of Science, and Cochrane Library databases to recruit studies in English. The quality assessment of diagnostic accuracy studies-2 protocol was used to evaluate the literature quality. Publication bias was analyzed using Deeks' funnel plot asymmetry test. We calculated the pooled sensitivity, specificity, positive likelihood ratio (PLR), negative likelihood ratio (NLR), diagnostic odds ratio (DOR), and 95% confidence interval (95% CI) for studies of micro-ultrasound imaging for prostate cancer. The results were assessed by the summary receiver-operating characteristic curve (SROC). Ultimately, a univariable meta-regression and subgroup analysis, Fagan plot, and a likelihood matrix were conducted.

Results: A total of seven studies containing 769 patients were included in this meta-analysis. Micro-ultrasound had a pooled sensitivity, specificity, DOR, and an area under the SROC of 0.91, 0.49, 10, and 0.82, respectively. Based on these findings, micro-ultrasound has superior ability to diagnose clinically significant prostate cancer.

Conclusion: Micro-ultrasound is a more convenient and cost-effective method in real-time imaging during the biopsy procedure in detecting clinically significant prostate cancer. Although micro-ultrasound has shown promising results, more clinical data and comprehensive analysis are still needed.

Purpose: This report presents our early experience at Cleveland Clinic replacing conventional ultrasound with a novel 29 MHz high-resolution micro-ultrasound system for both systematic sampling and real-time targeting of suspicious regions during prostate biopsy. The added value of micro-ultrasound and MRI over systematic biopsy is presented.

Methods: Sixty-seven consecutive subjects (January–August 2018) from our prospective database who underwent prostate biopsy using the micro-ultrasound system were included. 19/67 had prostate MRI imaging available. MRI targets were sampled using the UroNav fusion system. Patients had a median PSA of 5.37 ng/mL (IQR 4.13–8.74).

Results: 38/67 (56.7%) subjects were positive for prostate cancer. In six of these cases, systematic biopsy was negative with only micro-ultrasound targeted samples detecting cancer. In two other cases, patients were upgraded from Grade Group 1 to Grade Groups 4 and 2 based on micro-ultrasound targets. Micro-ultrasound targets detected cancer in two subjects where MRI was negative (Grade Groups 3 and 2). MRI targets alone did not change the overall diagnosis of any subjects. Switching biopsy guidance to real-time micro-ultrasound increased detection rate on prostate biopsy from 44.8% (30/67) to 56.7% (38/67), a relative increase of 26.7%.

Conclusion: High-resolution micro-ultrasound identified clinically significant cancer that would have, otherwise, been missed by both MRI fusion and systematic biopsy and was useful in both biopsy naïve and repeat negative patients. Early results from this small, single-center cohort are promising, particularly given the ease with which micro-ultrasound can replace the conventional ultrasound in standard prostate biopsy procedures.

Background: The PRI-MUSTM (Prostate Risk Identification for Micro-Ultrasound) protocol was developed in 2016 to identify suspicious areas seen by the ExactVu™ micro-ultrasound imaging platform. While a retrospective validation was performed, no prospective validation has been published in the peer-reviewed literature. Further, this protocol was developed for the peripheral zone and it is unclear whether the accuracy to predict clinically significant cancer is uniform throughout the gland.

Methods: 399 prostate biopsies were performed in 372 patients using the ExactVu micro-ultrasound system (Exact Imaging, Markham, Canada) from January 2018 to May 2019 at the Ordensklinikum Linz (Linz, Austria). Subjects had a median PSA of 6.7 (IQR 4.5-11.2) ng/mL and 30% had positive DRE. Suspicious areas were assessed in real-time using PRI-MUS and a TRUS biopsy was performed in the same session under microultrasound guidance. Biopsies were carried out by 5 providers and results from pathology were then compared with the image findings.

Results: Biopsy pathology confirmed a cancer diagnosis in 60% of patients, with 42% of patients harboring Grade Group (GG) > 1 cancer. The PRI-MUS protocol had an area under the receiver-operator characteristic (AUC) of 0.76 for predicting GG>1 cancer in the peripheral zone. This accuracy varied between 0.68-0.83 depending on prostate region, with highest accuracy in the prostate apex and lowest accuracy in the base. Anterior targets were sampled but generally not assigned a PRI-MUS score as the system is currently only validated in the peripheral zone, still, in the 33/737 anterior samples assigned a PRI-MUS score AUC was 0.80.

Conclusion: Micro-ultrasound and the PRI-MUS protocol are useful tools to detect cancer and appear to maintain strong diagnostic value throughout the prostate. This technology holds promise for reducing the high false-negative rate of prostate biopsy, without relying on multimodality, multi-specialty solutions like mpMRI.

Introduction: Active surveillance monitoring of prostate cancer is unique in that most patients have low-grade disease that is not well-visualized by any common imaging technique. High-resolution (29 MHz) micro-ultrasound is a new, real-time modality that has been demonstrated to be sensitive to significant prostate cancer and effective for biopsy targeting. This study compares micro-ultrasound imaging with magnetic resonance imaging (MRI) and conventional ultrasound for visualizing prostate cancer in active surveillance.

Methods: Nine patients on active surveillance were imaged with multiparametric (mp) MRI prior to biopsy. During the biopsy procedure, imaging and target identification was first performed using conventional ultrasound, then using micro-ultrasound. The mpMRI report was then unblinded and used to determine cognitive fusion targets. Using micro-ultrasound, biopsy samples were taken from targets in each modality, plus 12 systematic samples.

Results: mpMRI and micro-ultrasound both demonstrated superior sensitivity to Gleason sum 7 or higher cancer compared to conventional ultrasound (p=0.02 McNemar’s test). Micro-ultrasound detected 89% of clinically significant cancer, compared to 56% for mpMRI.

Conclusions: Micro-ultrasound may provide similar sensitivity to clinically significant prostate cancer as mpMRI and visualize all significant mpMRI targets. Unlike mpMRI, micro-ultrasound is performed in the office, in real-time during the biopsy procedure, and so is expected to maintain the cost-effectiveness of conventional ultrasound. Larger studies are needed before these results may be applied in a clinical setting.

Purpose: Conventional ultrasound systems operate at 6 to 9 MHz and serve as the standard of care to guide prostate biopsies. We present a protocol using a novel high resolution (29 MHz) transrectal prostate micro-ultrasound system. This protocol includes a scoring system to assess the risk of prostatic carcinoma and enable real-time targeted biopsies.

Materials and Methods: The ExactVu™ system is currently being used in a multisite, 2,000-patient, randomized clinical trial. Cine loops of 400 biopsies from this trial were used to create the PRI-MUS™ (prostate risk identification using micro-ultrasound) protocol and risk scale. Validation was performed in an independent, pathology blinded set of 100 cines. Three of the 5 investigators performing this validation were familiar with micro-ultrasound but naïve to the PRI-MUS protocol and they received only 1 hour of training.

Results: Each increase in risk score demonstrated a 10.1% increase (95% CI 9.3–10.8) in the probability of clinically significant cancer. The risk score also increased with Gleason sum and cancer length with a slope of 0.15 (95% CI 0.09–0.21) and 0.58 (95% CI 0.43–0.73), respectively. Sensitivity and specificity were 80% and 37%, respectively, and the mean ± SD ROC AUC was 60% ± 2%. The protocol was more accurate for detecting high grade disease (Gleason sum greater than 7) with a peak AUC of 74% (mean 66%).

Conclusions: The new resolution of the micro-ultrasound platform paired with the PRI-MUS protocol shows promise for real-time visualization of suspicious lesions and targeting of biopsies. The improved performance of the protocol in more significant disease is consistent with the focus of the field on decreasing insignificant diagnoses and detecting high risk disease early.

Objectives: To determine how high-resolution transrectal ultrasound (HiTRUS) compares with conventional TRUS (LoTRUS) for the visualization of prostate cancer.

Methods and materials: Twenty-five men with known prostate cancer scheduled for radical prostatectomy were preoperatively imaged with both LoTRUS (5 MHz) and HiTRUS (21 MHz). Dynamic cine loops and still images for each modality were saved and subjected to blinded review by a radiologist looking for hypoechoic foci≥5 mm in each sextant of the prostate. Following prostatectomy, areas of prostate cancer≥5 mm on pathologic review were anatomically correlated to LoTRUS and HiTRUS findings. The accuracy of LoTRUS and HiTRUS to visualize prostate cancer in each sextant of the prostate and to identify high-grade and locally advanced disease was assessed. The McNemar test was used to compare sensitivity and specificity and paired dichotomous outcomes between imaging modalities.

Results: Among 69 sextants with pathologically identified cancerous foci at radical prostatecomy, HiTRUS visualized 45 and missed 24, whereas LoTRUS visualized 26 and missed 43. Compared with LoTRUS, HiTRUS demonstrated improved sensitivity (65.2% vs. 37.7%) and specificity (71.6% vs. 65.4%). HiTRUS's agreement with pathologic findings was twice as high as LoTRUS (P = 0.006). HiTRUS provided a nonsignificant increase in visualization of high-grade lesions (84% vs. 60%, P = 0.11).

Conclusions: HiTRUS appears promising for prostate cancer imaging. Our initial experience suggests superiority to LoTRUS for the visualization of cancerous foci, and supports proceeding with a clinical trial in the biopsy setting.