Is magnetic resonance imaging-targeted biopsy a useful addition to systematic confirmatory biopsy in men on active surveillance for low-risk prostate cancer? A systematic review and meta-analysis

Early Results from the CONFIRM Trial: Utility of Prostate-specific Membrane Antigen Positron Emission Tomography/Computed Tomography in Active Surveillance for Prostate Cancer

BACKGROUND AND OBJECTIVE

There is growing evidence on the utility of prostate-specific membrane antigen (PSMA) positron emission tomography (PET)/computed tomography (CT) for detection of clinically significant prostate cancer (csPC), but there are limited data on its use in active surveillance (AS). The CONFIRM trial aims to determine the utility of PSMA PET/CT in detecting csPC before confirmatory biopsy during AS.

METHODS

This is an initial analysis of a prospective, nonrandomised, crossover clinical trial (ANZCTR ID ACTRN12621001648819) that included men on AS for newly diagnosed low-grade prostate cancer (PC) with "high-risk" features. High risk was defined as grade group (GG) 1 disease with elevated prostate-specific antigen (PSA; >10 ng/ml, or PSA density >0.15 ng/ml/ml), high-volume GG 1, GG 1 with Prostate Imaging-Reporting and Data System 4 or 5 lesion on magnetic resonance imaging (MRI), or low-volume GG 2 PC. Patients underwent multiparametric MRI and [18F]-labelled radioligand PSMA PET/CT 3-6 mo after diagnosis, and confirmatory biopsy 6-9 mo after diagnosis.

KEY FINDINGS AND LIMITATIONS

Between November 2021 and September 2023, 60 patients (median age 62.5 yr) were enrolled. PSMA-avid lesions were identified in 44 patients (73.3%), of whom 27 (61.4%) harboured csPC (GG ≥2). Of the PSMA-avid lesions, 20 (45.5%) were MRI-occult. At a subsequent multidisciplinary meeting, active treatment was recommended for 24 patients (40%), with PSMA PET/CT findings influencing 12 (20%) of the decisions. PSMA PET/CT provided reassurance regarding the decision to continue AS by excluding PSMA-avid lesions in 14 cases (38.9%) and multifocal disease in four (11.1%). Our findings are limited by the small sample size and short follow-up.

CONCLUSIONS AND CLINICAL IMPLICATIONS

PSMA PET/CT appears to hold promise for improving risk stratification during AS by identifying csPC and MRI-occult lesions.

MRI characteristics predict risk of pathological upgrade in patients with ISUP grade group 1 prostate cancer

OBJECTIVE

This study aims to analyse multiparametric MRI (mpMRI) characteristics of patients diagnosed with ISUP grade group (GG) 1 prostate cancer (PC) on initial target plus systematic MRI/TRUS fusion-guided biopsy and investigate histopathological progression during follow-up.

METHODS

A retrospective single-centre cohort analysis was conducted on consecutive patients with mpMRI visible lesions (PI-RADS ≥ 3) and detection of ISUP-1-PC at the time of initial biopsy. The study assessed clinical, mpMRI, and histopathological parameters. Subcohorts were analysed with (1) patients who had confirmed ISUP-1-PC and (2) patients who experienced histopathological upgrading to ISUP ≥ 2 PC during follow-up either at re-biopsy or radical prostatectomy (RP).

RESULTS

A total of 156 patients (median age 65 years) between March 2014 and August 2021 were included. Histopathological upgrading to ISUP ≥ 2 was detected in 55% of patients during a median follow-up of 9.5 months (IQR 2.2-16.4). When comparing subgroups with an ISUP upgrade and sustained ISUP 1 PC, they differed significantly in contact length of the index lesion to the pseudocapsule, ADC value, PI-RADS category, and the MRI grading group (mGG) (p < 0.05). In the ISUP GG ≥ 2 subgroup, 91% of men had PI-RADS category 4 or 5 and 82% exhibited the highest mGG (mGG3). In multivariate analysis, mGG was the only independent parameter for predicting ISUP ≥ 2-PC in these patients.

CONCLUSIONS

MRI reveals important information about PC aggressiveness and should be incorporated into clinical decision-making when ISUP-1-PC is diagnosed. In cases of specific MRI characteristics adverse to the histopathology, early re-biopsy might be considered.

CLINICAL RELEVANCE STATEMENT

In cases with clear MRI characteristics for clinically significant prostate cancer (e.g., mGG 3 and/or PI-RADS 5, cT3, or clear focal PI-RADS 4 lesions on MRI) and ISUP GG 1 PC diagnosed on initial prostate biopsy, MRI findings should be incorporated into clinical decision-making and early re-biopsy (e.g., within 6 months) might be considered.

KEY POINTS

MRI reveals important information about prostate cancer (PC) aggressiveness. MRI should be incorporated into clinical decision-making when ISUP GG 1 PC is diagnosed on initial prostate biopsy. In cases of specific MRI characteristics adverse to the histopathology, early re-biopsy might be considered.

MRI and active surveillance: thoughts from across the pond

In the United States (US), urological guidelines recommend active surveillance (AS) for patients with low-risk prostate cancer (PCa) and endorse it as an option for those with favorable intermediate-risk PCa with a > 10-year life expectancy. Multiparametric magnetic resonance imaging (mpMRI) is being increasingly used in the screening, monitoring, and staging of PCa and involves the combination of T2-weighted, diffusion-weighted, and dynamic contrast-enhanced T1-weighted imaging. The American Urological Association (AUA) guidelines provide recommendations about the use of mpMRI in the confirmatory setting for AS patients but do not discuss the timing of follow-up mpMRI in AS. The National Comprehensive Cancer Network (NCCN) discourages using it more frequently than every 12 months. Finally, guidelines state that mpMRI can be used to augment risk stratification but should not replace periodic surveillance biopsy. In this review, we discuss the current literature regarding the use of mpMRI for patients with AS, with a particular focus on the approach in the US. Although AS shows a benefit to the addition of mpMRI to diagnostic, confirmatory, and follow-up biopsy, there is no strong evidence to suggest that mpMRI can safely replace biopsy for most patients and thus it must be incorporated into a multimodal approach. CLINICAL RELEVANCE STATEMENT: According to the US guidelines, regular follow-ups are important for men with prostate cancer on active surveillance, and prostate MRI is a valuable tool that should be utilized, in combination with PSA kinetics and biopsies, for monitoring prostate cancer. KEY POINTS: According to the US guidelines, the addition of MRI improves the detection of clinically significant prostate cancer. Timing interval imaging of patients on active surveillance remains unclear and has not been specifically addressed. MRI should trigger further work-ups, but not replace periodic follow-up biopsies, in men on active surveillance.

Imaging in Diagnosis and Active Surveillance for Prostate Cancer: A Review

Importance

Active surveillance (AS) has become an increasingly important option for managing low-risk and select intermediate-risk prostate cancer. Although imaging, particularly multiparametric magnetic resonance imaging (mpMRI), has emerged in the prebiopsy pathway for the diagnosis of prostate cancer, the role of mpMRI in patient selection for AS and the necessity of prostate biopsies during AS remain poorly defined. Despite well-founded biopsy schedules, there has been substantial investigation into whether imaging may supplant the need for prostate biopsies during AS. This review aimed to summarize the contemporary role of imaging in the diagnosis and surveillance of prostate cancer.

Observations

Multiparametric MRI is the most established form of imaging in prostate cancer, with routine prebiopsy use being shown to help urologists distinguish between clinically significant and clinically insignificant disease. The visibility of these lesions on mpMRI closely correlates with their behavior, with visible disease portending a worse prognosis. Combined with other clinical data, risk calculators may better delineate patients with higher-risk disease and exclude them from undergoing AS. While current evidence suggests that mpMRI cannot replace the need for prostate biopsy during AS due to the possibility of missing higher-risk disease, the addition of prostate biomarkers may help to reduce the frequency of these biopsies. The role of prostate-specific antigen positron emission tomography/computed tomography is still emerging but has shown promising early results as an adjunct to mpMRI in initial diagnosis.

Conclusions and Relevance

Imaging in prostate cancer helps to better select patients appropriate for AS, and future studies may strengthen the predictive capabilities of risk calculators. Multiparametric MRI has been shown to be imperative to rationalizing biopsies for patients enrolled in AS. However, heterogeneity in the evidence of mpMRI during AS has suggested that further prospective studies and randomized clinical trials, particularly in homogenizing reporting standards, may reveal a more defined role in monitoring disease progression.

Is MRI ready to replace biopsy during active surveillance?

Active surveillance (AS) is a conservative management option recommended for patients diagnosed with low-risk prostate cancer (PCa) and selected cases with intermediate-risk PCa. The adoption of prostate MRI in the primary diagnostic setting has sparked interest in its application during AS. This review aims to examine the role and performance of multiparametric MRI (mpMRI) across the entire AS pathway, from initial stratification to follow-up, also relative to the utilization of the Prostate Cancer Radiological Estimation of Change in Sequential Evaluation (PRECISE) criteria. Given the high negative predictive value of mpMRI in detecting clinically significant PCa (csPCa), robust evidence supports its use in patient selection and risk stratification at the time of diagnosis or confirmatory biopsy. However, conflicting results have been observed when using MRI in evaluating disease progression during follow-up. Key areas requiring clarification include addressing the clinical significance of MRI-negative csPCa, optimizing MRI quality, determining the role of biparametric MRI (bpMRI) or mpMRI protocols, and integrating artificial intelligence (AI) for improved performance. CLINICAL RELEVANCE STATEMENT: MRI plays an essential role in the selection, stratification, and follow up of patients in active surveillance (AS) for prostate cancer. However, owing to existing limitations, it cannot fully replace biopsies in the context of AS. KEY POINTS: Multiparametric MRI (mpMRI) has become a crucial tool in active surveillance (AS) for prostate cancer (PCa). Conflicting results have been observed regarding multiparametric MRI efficacy in assessing disease progression. Standardizing MRI-guided protocols will be critical in addressing current limitations in active surveillance for prostate cancer.

Adequacy of clinical guideline recommendations for patients with low-risk cancer managed with monitoring: systematic review

OBJECTIVES

The aim of this systematic review was to summarize national and international guidelines that made recommendations for monitoring patients diagnosed with low-risk cancer. It appraised the quality of guidelines and determined whether the guidelines adequately identified patients for monitoring, specified which tests to use, defined monitoring intervals, and stated triggers for further intervention. It then assessed the evidence to support each recommendation.

STUDY DESIGN AND SETTING

Following the Preferred Reporting Items for Systematic Reviews and Meta-analyses, we searched PubMed and Turning Research into Practice databases for national and international guidelines' that were written in English and developed or updated between 2012 and 2023. Quality of individual guidelines was assessed using the AGREE II tool.

RESULTS

Across the 41 published guidelines, 48 different recommendations were identified: 15 (31%) for prostate cancer, 11 (23%) for renal cancer, 6 (12.5%) for thyroid cancer, and 10 (21%) for blood cancer. The remaining 6 (12.5%) were for brain, gastrointestinal, oral cavity, bone and pheochromocytoma and paraganglioma cancer. When combining all guidelines, 48 (100%) stated which patients qualify for monitoring, 31 (65%) specified which tests to use, 25 (52%) provided recommendations for surveillance intervals, and 23 (48%) outlined triggers to initiate intervention. Across all cancer sites, there was a strong positive trend with higher levels of evidence being associated with an increased likelihood of a recommendation being specific (P = 0.001) and the evidence for intervals was based on expert opinion or other guidance.

CONCLUSION

With the exception of prostate cancer, the evidence base for monitoring low-risk cancer is weak and consequently recommendations in clinical guidelines are inconsistent. There is a lack of direct evidence to support monitoring recommendations in the literature making guideline developers reliant on expert opinion, alternative guidelines, or indirect or nonspecific evidence.

Gallium-68 Prostate-specific Membrane Antigen Positron Emission Tomography/Computed Tomography in Active Surveillance for Prostate Cancer Trial (PASPoRT)

BACKGROUND

The use of clinical parameters, including prebiopsy magnetic resonance imaging (MRI), to decide between active surveillance (AS) and active therapy for prostate cancer (PCa) leads to imperfect selection. Additional prostate-specific membrane antigen (PSMA) positron emission tomography/computed tomography (PET/CT) imaging may improve risk stratification.

OBJECTIVE

To study risk stratification and patient selection for AS with the addition of PSMA PET/CT to standard practice.

DESIGN, SETTING, AND PARTICIPANTS

A single-centre prospective cohort study (NL69880.100.19) enrolled patients recently diagnosed with PCa who started AS. At diagnosis, all participants had undergone prebiopsy MRI and targeted biopsy for visualised lesions. Patients underwent an additional [68Ga]-PSMA PET/CT and targeted biopsy of all PSMA lesions with a maximum standardised uptake value (SUVmax) of ≥4 not covered by previous biopsies.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

The primary outcome was the number needed to scan (NNS) to detect one patient with upgrading. The study was powered to detect an NNS of 10. Regarding secondary outcomes, univariate logistic regressions analyses were performed on all patients and on the patients who received additional PSMA targeted biopsies on the likelihood of upgrading.

RESULTS AND LIMITATIONS

A total of 141 patients were included. Additional PSMA targeted biopsies were performed in 45 (32%) patients. In 13 (9%) patients, upgrading was detected: nine grade group (GG) 2, two GG 3, one GG 4, and one GG 5. The NNS was 11 (95% confidence interval 6-18). Of all participants, PSMA PET/CT and targeted biopsies yielded upgrading most frequently in patients with negative MRI (Prostate Imaging Reporting and Data System [PI-RADS] 1-2). Of patients who received additional PSMA targeted biopsies, upgrading was most frequently found in those with higher prostate-specific antigen density and negative MRI. Limitations included the lack of comparison with standard repeat biopsy, no central review of MRI, and possibility of biopsy sampling error.

CONCLUSIONS

PSMA PET/CT can further improve PCa risk stratification and selection for AS patients diagnosed after MRI and targeted biopsies.

PATIENT SUMMARY

Prostate-specific membrane antigen positron emission tomography/computed tomography and additional targeted prostate biopsies can identify more aggressive prostate cancer cases previously missed in patients recently started with expectant management for favourable-risk prostate cancer.

Role of targeted biopsy, perilesional biopsy, random biopsy, and their combination in the detection of clinically significant prostate cancer by mpMRI/transrectal ultrasonography fusion biopsy in confirmatory biopsy during active surveillance program

BACKGROUND

Based on the findings of different trials in biopsy naïve patients, target biopsy (TB) plus random biopsy (RB) during mpMRI-guided transrectal ultrasound fusion biopsy (FB) are often also adopted for the biopsy performed during active surveillance (AS) programs. At the moment, a clear consensus on the extent and modalities of the procedure is lacking.

OBJECTIVE

To evaluate the increase in diagnostic accuracy achieved by perilesional biopsy (PL) and different RB schemes during FB performed in AS protocol.

DESIGN, SETTING, AND PARTICIPANTS

We collected prospectively the data of 112 consecutive patients with low- or very-low-risk prostate cancer; positive mpMRI underwent biopsy at a single academic institution in the context of an AS protocol.

INTERVENTION(S)

mpMRI/transrectal US FB with Hitachi RVS system with 3 TB and concurrent transrectal 24-core RB.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

The diagnostic yield of the different possible biopsy schemes (TB only; TB + 4 perilesional (PL) cores; TB + 12-core RB; TB + 24-core RB) was compared by the McNemar test. Univariable and multivariable regression analyses were adopted to identify predictors of any cancer, Gleason grade group (GGG) ≥2 cancers, and the presence of GGG≥2 cancers in the larger schemes only.

RESULTS AND LIMITATIONS

The detection rate of GGG ≥2 cancers increased to 30%, 39%, and 49% by adding 4 PL cores, 14, and 24 RB cores, respectively, to TB cores (all p values <0.01). On the whole, TB alone, 14-core RB, and 24-core-RB identified 38%, 47%, and 56% of all the GGG ≥2 cancers. Such figures increased to 62% by adding to TB 4 PL cores, and to 80% by adding 14 RB cores. Most of the differences were observed in PI-RADS 4 lesions.

CONCLUSIONS

We found that PL biopsy increased the detection rate of GGG ≥2 cancers as compared with TB alone. However, the combination of those cores missed a large percentage of the CS cancers identified with larger RB cores, including a 20% of CS cancers diagnosed only by the combination of TB plus 24-core RB.

A Systematic Review on Prostate-Specific Membrane Antigen Positron Emission Tomography (PSMA PET) Evaluating Localized Low- to Intermediate-Risk Prostate Cancer: A Tool to Improve Risk Stratification for Active Surveillance?

Active surveillance remains a treatment option for low- to intermediate-risk prostate cancer (PCa) patients. Prostate-specific membrane antigen positron emission tomography and computed tomography (PSMA PET/CT) has emerged as a useful modality to assess intraprostatic lesions. This systematic review aims to evaluate PSMA PET/CT in localized low- to intermediate-risk PCa to determine its role in active surveillance. Following PRISMA guidelines, a search was performed on Medline, Embase, and Scopus. Only studies evaluating PSMA PET/CT in localized low- to intermediate-risk PCa were included. Studies were excluded if patients received previous treatment, or if they included high-risk PCa. The search yielded 335 articles, of which only four publications were suitable for inclusion. One prospective study demonstrated that PSMA PET/CT-targeted biopsy has superior diagnostic accuracy when compared to mpMRI. One prospective and one retrospective study demonstrated MRI occult lesions in 12.3-29% of patients, of which up to 10% may harbor underlying unfavorable pathology. The last retrospective study demonstrated the ability of PSMA PET/CT to predict the volume of Gleason pattern 4 disease. Early evidence demonstrated the utility of PSMA PET/CT as a tool in making AS safer by detecting MRI occult lesions and patients at risk of upgrading of disease.

Active Surveillance for Prostate Cancer: Expanding the Role of MR Imaging and the Use of PRECISE Criteria

Multiparametric magnetic resonance (MR) imaging has had an expanding role in active surveillance (AS) for prostate cancer. It can improve the accuracy of prostate biopsies, assist in patient selection, and help monitor cancer progression. The PRECISE recommendations standardize reporting of serial MR imaging scans during AS. We summarize the evidence on MR imaging-led AS and provide a clinical primer to help report using the PRECISE criteria. Some limitations to both serial imaging and the PRECISE recommendations must be considered as we move toward a more individualized risk-stratified approach to AS.

Zone-specific computer-aided diagnosis system aimed at characterizing ISUP ≥ 2 prostate cancers on multiparametric magnetic resonance images: evaluation in a cohort of patients on active surveillance

PURPOSE

To assess a region-of-interest-based computer-assisted diagnosis system (CAD) in characterizing aggressive prostate cancer on magnetic resonance imaging (MRI) from patients under active surveillance (AS).

METHODS

A prospective biopsy database was retrospectively searched for patients under AS who underwent MRI and subsequent biopsy at our institution. MRI lesions targeted at baseline biopsy were retrospectively delineated to calculate the CAD score that was compared to the Prostate Imaging-Reporting and Data System (PI-RADS) version 2 score assigned at baseline biopsy.

RESULTS

186 patients were selected. At baseline biopsy, 51 and 15 patients had International Society of Urological Pathology (ISUP) grade ≥ 2 and ≥ 3 cancer respectively. The CAD score had significantly higher specificity for ISUP ≥ 2 cancers (60% [95% confidence interval (CI): 51-68]) than the PI-RADS score (≥ 3 dichotomization: 24% [CI: 17-33], p = 0.0003; ≥ 4 dichotomization: 32% [CI: 24-40], p = 0.0003). It had significantly lower sensitivity than the PI-RADS ≥ 3 dichotomization (85% [CI: 74-92] versus 98% [CI: 91-100], p = 0.015) but not than the PI-RADS ≥ 4 dichotomization (94% [CI:85-98], p = 0.104). Combining CAD findings and PSA density could have avoided 47/184 (26%) baseline biopsies, while missing 3/51 (6%) ISUP 2 and no ISUP ≥ 3 cancers. Patients with baseline negative CAD findings and PSAd < 0.15 ng/mL2 who stayed on AS after baseline biopsy had a 9% (4/44) risk of being diagnosed with ISUP ≥ 2 cancer during a median follow-up of 41 months, as opposed to 24% (18/74) for the others.

CONCLUSION

The CAD could help define AS patients with low risk of aggressive cancer at baseline assessment and during subsequent follow-up.

The PRECISE Recommendations for Prostate MRI in Patients on Active Surveillance for Prostate Cancer: A Critical Review

The Prostate Cancer Radiological Estimation of Change in Sequential Evaluation (PRECISE) recommendations were published in 2016 to standardize the reporting of MRI examinations performed to assess for disease progression in patients on active surveillance for prostate cancer. Although a limited number of studies have reported outcomes from use of PRECISE in clinical practice, the available studies have demonstrated PRECISE to have high pooled NPV but low pooled PPV for predicting progression. Our experience in using PRECISE in clinical practice at two teaching hospitals has highlighted issues with its application and areas requiring clarification. This Clinical Perspective critically appraises PRECISE on the basis of this experience, focusing on the system's key advantages and disadvantages and exploring potential changes to improve the system's utility. These changes include consideration of image quality when applying PRECISE scoring, incorporation of quantitative thresholds for disease progression, adoption of a PRECISE 3F sub-category for progression not qualifying as substantial, and comparisons with both the baseline and most recent prior examinations. Items requiring clarification include derivation of a patient-level score in patients with multiple lesions, intended application of PRECISE score 5 (i.e., if requiring development of disease that is no longer organ-confined), and categorization of new lesions in patients with prior MRI-invisible disease.

Could Prognostic Nutritional Index be a new criteria for active surveillance of prostate cancer?

OBJECTIVE

To evaluate the importance of the Prognotic Nutritional Index(PNI) value for patient selection of active surveillance(AS) in prostate cancer.

METHODS

Between September 2020 and June 2022, the data of 125-patients who underwent Robot-Assisted-Laparoscopic-Prostatectomy(RALP) were retrospectively analyzed. All patients were suitable for AS preoperatively. Using the pathological results of RALP, patients have been divided two groups. Patients who met the criteria for AS were defined as the first group, others were defined second. Demographic datas, PNI values and hematological parameters of the groups were compared.

RESULTS

38% (n:48) patients were found suitable for the group1, and 62%(n:77) were found suitable for the group 2. Upgrading and upstaging were found at 76 patients (61%) and 26(21%), respectively. There is no significant difference between groups on age, BMI, PSA, PSA-density, prostate volume, and PIRADS. PNI value was found higher at first group. The value of 49.45 was calculated by ROC analysis as the ideal PNI cut-off value for predicting upgrading and upstaging of prostate cancer (P < ,001). According to the both univariate and multivariate regression analysis, PNI was found a predictor for exclusion from AS (P < ,001).

CONCLUSION

Upgrading and upstaging are detected at a higher rate in patients with low PNI values. The use of PNI value in the selection of patients to AS will increase the success rate of ideal patient selection.

Stability of Multi-Parametric Prostate MRI Radiomic Features to Variations in Segmentation

Stability analysis remains a fundamental step in developing a successful imaging biomarker to personalize oncological strategies. This study proposes an in silico contour generation method for simulating segmentation variations to identify stable radiomic features. Ground-truth annotation provided for the whole prostate gland on the multi-parametric MRI sequences (T2w, ADC, and SUB-DCE) were perturbed to mimic segmentation differences observed among human annotators. In total, we generated 15 synthetic contours for a given image-segmentation pair. One thousand two hundred twenty-four unfiltered/filtered radiomic features were extracted applying Pyradiomics, followed by stability assessment using ICC(1,1). Stable features identified in the internal population were then compared with an external population to discover and report robust features. Finally, we also investigated the impact of a wide range of filtering strategies on the stability of features. The percentage of unfiltered (filtered) features that remained robust subjected to segmentation variations were T2w-36% (81%), ADC-36% (94%), and SUB-43% (93%). Our findings suggest that segmentation variations can significantly impact radiomic feature stability but can be mitigated by including pre-filtering strategies as part of the feature extraction pipeline.

Fusion-targeted biopsy significantly improves prostate cancer detection in biopsy-naïve men

OBJECTIVE

The precise diagnosis of prostate cancer (PC) is crucial to avoid underdiagnosis, overdiagnosis, and overtreatment. We aimed to compare clinically significant PC (csPC) detection between MRI/ultrasound fusion-targeted prostate (TBx) compared to systematic biopsy (SBx) in biopsy-naïve Japanese men.

METHODS

We included patients with suspect PC due to elevated PSA level or abnormal digital rectal examination, or both. csPC was defined as International Society Urological Pathology (ISUP) grade group ≥2 (csPC-A) and ISUP grade group ≥3 (csPC-B).

RESULTS

This study included 143 patients. Overall PC detection was 66.4% for SBx and 67.8% for MRI-TBx. MRI-TBx presented a significantly higher rate of csPC detection (csPC-A 67.1% vs. 58.7%, p = 0.04, and csPC-B 49.6% vs. 39.9%, p < 0.001) and significantly lower detection of non-csPC-A (0.6% vs. 6.7%). Importantly, MRI-TBx missed 4.9% (7/143) of csPC-A and only 0.7% (1/143) of csPC-B. On the other hand, SBx alone missed 13.3% (19/143) of csPC-A and 4.2% (6/143) of csPC-B.

CONCLUSION

MRI-TBx significantly outperformed 12-cores SBx for csPC detection and decreased non-csPC detection in biopsy-naive men. Performing MRI-TBx without SBx would have missed some csPC, supporting that MRI-TBx synergizes with SBx to increase csPC detection.

mpMRI Interpretation in Active Surveillance for Prostate Cancer-An overview of the PRECISE score

Active surveillance (AS) is now included in all major guidelines for patients with low-risk PCa and selected patients with intermediate-risk PCa. Several studies have highlighted the potential benefit of multiparametric magnetic resonance imaging (mpMRI) in AS and it has been adopted in some guidelines. However, uncertainty remains about whether serial mpMRI can help to safely reduce the number of required repeat biopsies under AS. In 2017, the European School of Oncology initiated the Prostate Cancer Radiological Estimation of Change in Sequential Evaluation (PRECISE) panel which proposed the PRECISE scoring system to assess the likelihood of radiological tumor progression on serial mpMRI. The PRECISE scoring system remains the only major system evaluated in multiple publications. In this review article, we discuss the current body of literature investigating the application of PRECISE as it is not as yet an established standard in mpMRI reporting. We delineate the strengths of PRECISE and its potential added value. Also, we underline potential weaknesses of the PRECISE scoring system, which might be tackled in future versions to further increase its value in AS.

Abbreviated Versus Multiparametric Prostate MRI in Active Surveillance for Prostate-Cancer Patients: Comparison of Accuracy and Clinical Utility as a Decisional Tool

(1) Purpose: To compare the diagnostic accuracy between full multiparametric contrast-enhanced prostate MRI (mpMRI) and abbreviated dual-sequence prostate MRI (dsMRI) in men with clinically significant prostate cancer (csPCa) who were candidates for active surveillance. (2) Materials and Methods: Fifty-four patients with a diagnosis of low-risk PCa in the previous 6 months had a mpMRI scan prior to a saturation biopsy and a subsequent MRI cognitive transperineal targeted biopsy (for PI-RADS ≥ 3 lesions). The dsMRI images were obtained from the mpMRI protocol. The images were selected by a study coordinator and assigned to two readers blinded to the biopsy results (R1 and R2). Inter-reader agreement for clinically significant cancer was evaluated with Cohen's kappa. The dsMRI and mpMRI accuracy was calculated for each reader (R1 and R2). The clinical utility of the dsMRI and mpMRI was investigated with a decision-analysis model. (3) Results: The dsMRI sensitivity and specificity were 83.3%, 31.0%, 75.0%, and 23.8%, respectively, for R1 and R2. The mpMRI sensitivity and specificity were 91.7%, 31.0%, 83.3%, and 23.8%, respectively, for R1 and R2. The inter-reader agreement for the detection of csPCa was moderate (k = 0.53) and good (k = 0.63) for dsMRI and mpMRI, respectively. The AUC values for the dsMRI were 0.77 and 0.62 for the R1 and R2, respectively. The AUC values for the mpMRI were 0.79 and 0.66 for R1 and R2, respectively. No AUC differences were found between the two MRI protocols. At any risk threshold, the mpMRI showed a higher net benefit than the dsMRI for both R1 and R2. (4) Conclusions: The dsMRI and mpMRI showed similar diagnostic accuracy for csPCa in male candidates for active surveillance.

Interaction of MRI and active surveillance in prostate cancer: Time to re-evaluate the active surveillance inclusion criteria

Currently available data from long-running single- and multi-center active surveillance (AS) studies show that AS has excellent cancer-specific survival rates. For AS to be effective the 'right' patients should be selected for which up until 5-to-10 years ago systematic prostate biopsies were used. Because the systematic prostate strategy relies on sampling efficiency for the detection of prostate cancer (PCa), it is subject to sampling error. Due to this sampling error, many of the Gleason 3+3 PCas that were included on AS in the early days and were classified as low-risk, may in fact have had a higher Gleason score. Subsequently, AS-criteria were more strict to overcome or limit the number of men missing the potential window of curability in case their tumor would be reclassified. Five to ten years ago the prostate biopsy landscape changed drastically by the addition of magnetic resonance imaging (MRI) into the diagnostic PCa-care pathway, which has by now trickled down into the EAU guidelines. At the moment, the EAU guidelines recommend performing a (multi-parametric) MRI before prostate biopsy and combine systematic and targeted prostate biopsy when the MRI is positive (i.e. PIRADS ≥3). So because of the introduction of the MRI into the diagnostic PCa-care pathway, literature is showing that more Gleason 3+4 PCas are being diagnosed. But can it not be that the inclusion of MRI into the diagnostic PCa-care pathway causes risk inflation, resulting in men earlier eligible for AS, now being labelled ineligible for AS? Would it not be possible to include these current Gleason 3+4 PCas on AS? The authors hypothesize that the improved accuracy that comes with the introduction of MRI into the diagnostic PCa-care pathway permits to widen both the AS-inclusion and follow-up criteria. Maintaining our inclusion criteria for AS from the systematic biopsy era will unnecessarily and undesirably expose patients to the increased risk of overtreatment. The evidence behind the addition of MRI-targeted biopsies to systematic biopsies calls upon the re-evaluation of the AS inclusion criteria and research from one-size-fits-all protocols used so far, into the direction of more dynamic and individual risk-based AS-approaches.

Risk and predictors of adverse pathology after radical prostatectomy in patients diagnosed with IUSP 1-2 prostate cancer at MRI-targeted biopsy: a multicenter analysis

PURPOSE

Although active surveillance (AS) is recommended for low- to favorable intermediate-risk prostate cancer (PCa), risk of upgrading at radical prostatectomy (RP) is not negligible. Available studies based on systematic transrectal ultrasound biopsy might not be applicable to contemporary cohorts diagnosed with MRI-targeted biopsy (TB). The aim of the present study is to explore rates and risk factors for adverse outcomes (AO) at RP in patients with ISUP ≤ 2 PCa detected at TB with concomitant systematic biopsy (SB).

METHODS

Multicenter, retrospective analysis of 475 consecutive patients with ISUP ≤ 2 PCa at MRI-TB + SB is treated with RP. AO were defined as ISUP upgrading, adverse pathology (upgrading to ISUP ≥ 3 and/or ≥ pT3 at RP, and/or pN1) (AP) or biochemical recurrence (BCR) in men with follow-up (n = 327).

RESULTS

The rate of ISUP upgrading, upgrading ≥ 3, and AP were 39%, 21%, and 43%. Compared to ISUP2, men with ISUP1 PCa had a higher rate of overall upgrading (27 vs. 67%, p < 0.001), but less upgrading to ≥ 3 (27 vs. 10%, p < 0.001). AP was more common when ISUP2 was detected with a combined MRI-TB + SB approach compared to considering TB (p = 0.02) or SB (p = 0.01) alone. PSA, PSA density, PI-RADS, ISUP at TB, overall biopsy ISUP and EAU classification were predictors of upgrading to ISUP ≥ 3 and AP. The 1 year BCR-free survival was 94% with no differences in BCR rates between subgroups.

CONCLUSION

Upgrading in ISUP ≤ 2 PCa remains prevalent even in men diagnosed in the MRI era. The use of MRI-TB with concomitant SB allows for the accurate identification of ISUP2 PCa and predicts the risk of AO at RP.

A Multivariable Approach Using Magnetic Resonance Imaging to Avoid a Protocol-based Prostate Biopsy in Men on Active Surveillance for Prostate Cancer-Data from the International Multicenter Prospective PRIAS Study

BACKGROUND

There is ongoing discussion whether a multivariable approach including magnetic resonance imaging (MRI) can safely prevent unnecessary protocol-advised repeat biopsy during active surveillance (AS).

OBJECTIVE

To determine predictors for grade group (GG) reclassification in patients undergoing an MRI-informed prostate biopsy (MRI-Bx) during AS and to evaluate whether a confirmatory biopsy can be omitted in patients diagnosed with upfront MRI.

DESIGN, SETTING, AND PARTICIPANTS

The Prostate cancer Research International: Active Surveillance (PRIAS) study is a multicenter prospective study of patients on AS (www.prias-project.org). We selected all patients undergoing MRI-Bx (targeted ± systematic biopsy) during AS.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

A time-dependent Cox regression analysis was used to determine the predictors of GG progression/reclassification in patients undergoing MRI-Bx. A sensitivity analysis and a multivariable logistic regression analysis were also performed.

RESULTS AND LIMITATIONS

A total of 1185 patients underwent 1488 MRI-Bx sessions. The time-dependent Cox regression analysis showed that age (per 10 yr, hazard ratio [HR] 0.84 [95% confidence interval {CI} 0.71-0.99]), MRI outcome (Prostate Imaging Reporting and Data System [PIRADS] 3 vs negative HR 2.46 [95% CI 1.56-3.88], PIRADS 4 vs negative HR 3.39 [95% CI 2.28-5.05], and PIRADS 5 vs negative HR 4.95 [95% CI 3.25-7.56]), prostate-specific antigen (PSA) density (per 0.1 ng/ml cm³, HR 1.20 [95% CI 1.12-1.30]), and percentage positive cores on the last systematic biopsy (per 10%, HR 1.16 [95% CI 1.10-1.23]) were significant predictors of GG reclassification. Of the patients with negative MRI and a PSA density of <0.15 ng/ml cm³ (n = 315), 3% were reclassified to GG ≥2 and 0.6% to GG ≥3. At the confirmatory biopsy, reclassification to GG ≥2 and ≥3 was observed in 23% and 7% of the patients diagnosed without upfront MRI and in 19% and 6% of the patients diagnosed with upfront MRI, respectively. The multivariable analysis showed no significant difference in upgrading at the confirmatory biopsy between patients diagnosed with or without upfront MRI.

CONCLUSIONS

Age, MRI outcome, PSA density, and percentage positive cores are significant predictors of reclassification at an MRI-informed biopsy. Patients with negative MRI and a PSA density of <0.15 ng/ml cm³ can safely omit a protocol-based prostate biopsy, whereas in other patients, a multivariable approach is advised. Being diagnosed with upfront MRI appears not to significantly affect reclassification risk; hence, a confirmatory MRI-Bx cannot totally be omitted yet.

PATIENT SUMMARY

A protocol-based prostate biopsy while on active surveillance can be omitted in patients with negative magnetic resonance imaging (MRI) and prostate-specific antigen density <0.15 ng/ml cm³. A confirmatory biopsy cannot simply be omitted in all patients diagnosed with upfront MRI.

Targeted Multiparametric Magnetic Resonance Imaging/Ultrasound Fusion Biopsy for Quantitative Gleason 4 Grading Prediction in Radical Prostatectomy Specimens: Implications for Active Surveillance Candidate Selection

BACKGROUND

Quantitative Gleason grading appears to be a reliable prognostic parameter and provides broader risk stratification then the traditional Gleason grading in patients with prostate cancer (PCa) treated with radical prostatectomy (RP).

OBJECTIVE

To determine if quantification of Gleason pattern (GP) 4 for targeted and systematic biopsy (TBx + SBx) cores together with further clinical variables can identify the lowest quantitative GP 4 fraction on RP.

DESIGN, SETTING, AND PARTICIPANTS

A total of 548 patients underwent TBx + SBx of the prostate and then RP, with pathology revealing Gleason score 3 + 4, 4 + 3, or 4 + 4 disease.

INTERVENTION

TBx + SBx of the prostate followed by RP.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

GP 4 fraction thresholds of ≤5%, ≤10%, ≤15%, ≤20%, and ≤25% were compared between the TBx + SBx and RP specimens. The sensitivity, specificity, negative predictive value (NPV), positive predictive value (PPV), and accuracy for predicting the GP 4 fraction in the RP specimen were determined. Logistic regression models were used to establish a probabilistic relationship between various combinations of clinical and biopsy variables and the GP 4 fraction in the RP specimen.

RESULTS AND LIMITATIONS

GP 4 fractions of ≤5%, ≤10%, ≤15%, ≤20%, and ≤25% was observed in 33%, 49%, 58%, 65%, and 70% of patients on TBx, and 18%, 41%, 53%, 63%, and 70% of patients on RP, respectively. The sensitivity, specificity, NPV, PPV, and accuracy were 75%, 67%, 91%, 39%, and 74% for a TBx GP 4 fraction of ≤5%, and 65%, 85%, 65%, 85%, and 79% for a TBx GP 4 fraction of ≤25%, respectively. A model combining quantified TBx + SBx GP 4 with clinical parameters demonstrated the highest diagnostic accuracy. Limitations include the retrospective study design.

CONCLUSIONS

Our results demonstrate that the combination of MRI-TBx + SBx and GP 4 quantification allowed precise detection of a low fraction of GP 4 when using RP specimens as the reference standard. Moreover, we found that clinical variables including Prostate Imaging-Reporting and Data System score without biopsy are limited in detection of low GP 4 fractions.

PATIENT SUMMARY

Combination of targeted biopsy alone as well as combined with systematic biopsy and quantitative Gleason grading of biopsy specimen showed high agreement with pathology findings after surgical removal of the prostate. This could help in identifying patients who are suitable for active surveillance.

Active Surveillance in Intermediate-Risk Prostate Cancer: A Review of the Current Data

Simple Summary

AS is an option for the initial management of selected patients with intermediate-risk PC. The proper way to predict which men will have an aggressive clinical course or indolent PC who would benefit from AS has not been unveiled. Genetics and MRI can help in the decision-making, but it remains unclear which men would benefit from which tests. In addition, there are several differences between AS protocols in inclusion criteria, monitoring follow-up, and triggers for active treatment. Large series and a few RCTs are under investigation, and more research is needed to establish an optimal therapeutic strategy for patients with intermediate-risk PC. This study summarizes the current data on patients with intermediate-risk PC under AS, recent findings, and discusses future directions.

Abstract

Active surveillance (AS) is a monitoring strategy to avoid or defer curative treatment, minimizing the side effects of radiotherapy and prostatectomy without compromising survival. AS in intermediate-risk prostate cancer (PC) has increasingly become used. There is heterogeneity in intermediate-risk PC patients. Some of them have an aggressive clinical course and require active treatment, while others have indolent disease and may benefit from AS. However, intermediate-risk patients have an increased risk of metastasis, and the proper way to select the best candidates for AS is unknown. In addition, there are several differences between AS protocols in inclusion criteria, monitoring follow-up, and triggers for active treatment. A few large series and randomized trials are under investigation. Therefore, more research is needed to establish an optimal therapeutic strategy for patients with intermediate-risk disease. This study summarizes the current data on patients with intermediate-risk PC under AS, recent findings, and discusses future directions.

Promoting the use of the PRECISE score for prostate MRI during active surveillance: results from the ESOR Nicholas Gourtsoyiannis teaching fellowship

Objectives

The PRECISE criteria for serial multiparametric magnetic resonance imaging (MRI) of the prostate during active surveillance recommend the use of a dedicated scoring system (PRECISE score) to assess the likelihood of clinically significant radiological change. This pilot study assesses the effect of an interactive teaching course on prostate MRI during active surveillance in assessing radiological change in serial imaging.

Methods

Eleven radiology fellows and registrars with different experience in prostate MRI reading participated in a dedicated teaching course where they initially evaluated radiological change (based on their previous training in prostate MRI reading) independently in fifteen patients on active surveillance (baseline and follow-up scan), and then attended a lecture on the PRECISE score. The initial scans were reviewed for teaching purposes and afterwards the participants re-assessed the degree of radiological change in a new set of images (from fifteen different patients) applying the PRECISE score. Receiver operating characteristic analysis was performed. Confirmatory biopsies and PRECISE scores given in consensus by two radiologists (involved in the original draft of the PRECISE score) were the reference standard.

Results

There was a significant improvement in the average area under the curve (AUC) for the assessment of radiological change from baseline (AUC: 0.60 [Confidence Intervals: 0.51–0.69] to post-teaching (AUC: 0.77 [0.70–0.84]). This was an improvement of 0.17 [0.016–0.28] (p = 0.004).

Conclusions

A dedicated teaching course on the use of the PRECISE score improves the accuracy in the assessment of radiological change in serial MRI of the prostate.

Implications and effects of COVID-19 on diagnosis and management of prostate cancer

PURPOSE OF REVIEW

The Coronavirus disease 2019 (COVID-19) pandemic has led to uncertainty on the optimal management for prostate cancer (PCa). This narrative review aims to shed light on the optimal diagnosis and management of patients with or suspected to have PCa.

RECENT FINDINGS

Faecal-oral or aerosol transmission is possible during prostate procedures; caution must be in place when performing digital rectal examinations, transrectal ultrasound-guided prostate biopsies and prostate surgeries requiring general anaesthesia. Patients must also be triaged using preoperative polymerase chain reaction tests for COVID-19. COVID-19 has accelerated the adoption of multiparametric Magnetic Resonance Imaging (MRI), reducing the need for prostate biopsy unless when absolutely indicated, and the risk of COVID-19 spread can be reduced. Combined with prostate-specific antigen (PSA) density, amongst other factors, multiparametric MRI could reduce unnecessary biopsies in patients with little chance of clinically significant PCa. Treatment of PCa should be stratified by the risk level and preferences of the patient. COVID-19 has accelerated the development of telemedicine and clinicians should utilise safe and effective teleconsultations to protect themselves and their patients.

SUMMARY

COVID-19 transmission during prostate procedures is possible. Patients with a Prostate Imaging-Reporting and Data System (PI-RADS) of <3 and PSA density <0.15 ng/ml/ml are deemed low-risk and are safe to undergo surveillance without MRI-targeted biopsy. Intermediate- or high-risk patients should be offered definitive treatment within four months or 30days of diagnosis to avoid compromising treatment outcomes; three-month courses of neoadjuvant androgen deprivation therapy can be considered when a delay of surgery is anticipated.

Alternatives for MRI in Prostate Cancer Diagnostics-Review of Current Ultrasound-Based Techniques

The purpose of this review is to present the current role of ultrasound-based techniques in the diagnostic pathway of prostate cancer (PCa). With overdiagnosis and overtreatment of a clinically insignificant PCa over the past years, multiparametric magnetic resonance imaging (mpMRI) started to be recommended for every patient suspected of PCa before performing a biopsy. It enabled targeted sampling of the suspicious prostate regions, improving the accuracy of the traditional systematic biopsy. However, mpMRI is associated with high costs, relatively low availability, long and separate procedure, or exposure to the contrast agent. The novel ultrasound modalities, such as shear wave elastography (SWE), contrast-enhanced ultrasound (CEUS), or high frequency micro-ultrasound (MicroUS), may be capable of maintaining the performance of mpMRI without its limitations. Moreover, the real-time lesion visualization during biopsy would significantly simplify the diagnostic process. Another value of these new techniques is the ability to enhance the performance of mpMRI by creating the image fusion of multiple modalities. Such models might be further analyzed by artificial intelligence to mark the regions of interest for investigators and help to decide about the biopsy indications. The dynamic development and promising results of new ultrasound-based techniques should encourage researchers to thoroughly study their utilization in prostate imaging.

Diagnostic Accuracy of Contemporary Selection Criteria in Prostate Cancer Patients Eligible for Active Surveillance: A Bayesian Network Meta-Analysis

Background

Several active surveillance (AS) criteria have been established to screen insignificant prostate cancer (insigPCa, defined as organ confined, low grade and small volume tumors confirmed by postoperative pathology). However, their comparative diagnostic performance varies. The aim of this study was to compare the diagnostic accuracy of contemporary AS criteria and validate the absolute diagnostic odds ratio (DOR) of optimal AS criteria.

Methods

First, we searched Pubmed and performed a Bayesian network meta-analysis (NMA) to compare the diagnostic accuracy of contemporary AS criteria and obtained a relative ranking. Then, we searched Pubmed again to perform another meta-analysis to validate the absolute DOR of the top-ranked AS criteria derived from the NMA with two endpoints: insigPCa and favorable disease (defined as organ confined, low grade tumors). Subgroup and meta-regression analyses were conducted to identify any potential heterogeneity in the results. Publication bias was evaluated.

Results

Seven eligible retrospective studies with 3,336 participants were identified for the NMA. The diagnostic accuracy of AS criteria ranked from best to worst, was as follows: Epstein Criteria (EC), Yonsei criteria, Prostate Cancer Research International: Active Surveillance (PRIAS), University of Miami (UM), University of California-San Francisco (UCSF), Memorial Sloan-Kettering Cancer Center (MSKCC), and University of Toronto (UT). I² = 50.5%, and sensitivity analysis with different insigPCa definitions supported the robustness of the results. In the subsequent meta-analysis of DOR of EC, insigPCa and favorable disease were identified as endpoints in ten and twenty-two studies, respectively. The pooled DOR for insigPCa and favorable disease were 0.44 (95%CI, 0.31–0.58) and 0.66 (95%CI, 0.61–0.71), respectively. According to a subgroup analysis, the DOR for favorable disease was significantly higher in US institutions than that in other regions. No significant heterogeneity or evidence of publication bias was identified.

Conclusions

Among the seven AS criteria evaluated in this study, EC was optimal for positively identifying insigPCa patients. The pooled diagnostic accuracy of EC was 0.44 for insigPCa and 0.66 when a more liberal endpoint, favorable disease, was used.

Systematic Review Registration

[https://www.crd.york.ac.uk/prospero/], PROSPERO [CRD42020157048].

Active surveillance inclusion criteria under scrutiny in magnetic resonance imaging-guided prostate biopsy: a multicenter cohort study

BACKGROUND

Although multiparametric magnetic resonance imaging (mpMRI) is recommended for primary risk stratification and follow-up in Active Surveillance (AS), it is not part of common AS inclusion criteria. The objective was to compare AS eligibility by systematic biopsy (SB) and combined MRI-targeted (MRI-TB) and SB within real-world data using current AS guidelines.

METHODS

A retrospective multicenter study was conducted by a German prostate cancer (PCa) working group representing six tertiary referral centers and one outpatient practice. Men with PCa and at least one MRI-visible lesion according to Prostate Imaging Reporting and Data System (PI-RADS) v2 were included. Twenty different AS inclusion criteria of international guidelines were applied to calculate AS eligibility using either a SB or a combined MRI-TB and SB. Reasons for AS exclusion were assessed.

RESULTS

Of 1941 patients with PCa, per guideline, 583-1112 patients with PCa in both MRI-TB and SB were available for analysis. Using SB, a median of 22.1% (range 6.4-72.4%) were eligible for AS. Using the combined approach, a median of 15% (range 1.7-68.3%) were eligible for AS. Addition of MRI-TB led to a 32.1% reduction of suitable patients. Besides Gleason Score upgrading, the maximum number of positive cores were the most frequent exclusion criterion. Variability in MRI and biopsy protocols potentially limit the results.

CONCLUSIONS

Only a moderate number of patients with PCa can be monitored by AS to defer active treatment using current guidelines for inclusion in a real-world setting. By an additional MRI-TB, this number is markedly reduced. These results underline the need for a contemporary adjustment of AS inclusion criteria.

MRI-directed biopsy for primary detection of prostate cancer in a population of 223 men: MRI In-Bore vs MRI-transrectal ultrasound fusion-targeted techniques

Objectives:

To compare the detection rates of overall prostate cancer (PCa) and clinically significant PCa (csPCa) and the median percentage of cancer per biopsy core between MRI-guided In-bore and MRI-TRUS fusion-targeted biopsy (TBx).

Methods:

In this retrospective study, 223 patients who underwent prostate multiparametric MRI (mpMRI) and subsequent MR-directed biopsy were included. For PCa and csPCa detection rate (DR), contingency tables were tested via the Pearson’s chi-squared to explore the variance of the outcome distribution. The percentage of cancer per biopsy core was tested with a two-tailed Mann-Withney test.

Results:

One hundred and seventeen and 106 patients underwent MRI-TRUS fusion or MRI In-bore TBx, respectively. 402 MRI biopsy targets were identified, of which 206 (51.2%) were biopsied with the MRI-TRUS TBx and 196 (48.8%) with the MRI In-bore TBx technique. Per-patient PCa and csPCa detection rates were 140/223 (62.8%) and 97/223 (43.5%), respectively. PCa-DR was 73/117 (62.4%) and 67/106 (63.2%) for MRI-TRUS and MRI In-Bore TBx (p = 0.9), while csPCa detection rate reached 50/117 (42.7%) and 47/106 (44.3%), respectively (p = 0.81). The median per-patient percentage of malignant tissue within biopsy cores was 50% (IQR: 27–65%) for PCa and 60% (IQR: 35–68%) for csPCa, with a statistically significant difference between the techniques.

Conclusion

No statistically significant difference in the detection rate of MRI In-bore and MRI-TRUS fusion TBx was found. MRI In-bore TBx showed higher per-core percentage of malignant cells.

Advances in knowledge

MRI In-bore biopsy might impact risk stratification and patient management considering the higher per-core percentage of malignant cells, especially for patients eligible for active surveillance or focal therapy.

Use of multiparametric magnetic resonance imaging (mpMRI) in active surveillance for low-risk prostate cancer: a scoping review on the benefits and harm of mpMRI in different biopsy scenarios

BACKGROUND

There is uncertainty on how multiparametric MRI (mpMRI) and MRI-targeted biopsy (MRI-TB) can be best used to manage low-risk prostate cancer patients on Active Surveillance (AS). We performed a scoping review to evaluate the benefits and harm associated with four different biopsy scenarios in which mpMRI can be implemented in AS.

METHODS

Medline, Embase and Cochrane Library databases (1 January 2013-18 September 2020) were searched. Included studies were on men with low-risk prostate cancer enrolled in AS, who had mpMRI ± MRI-TB and standard prostate biopsy (systematic transrectal ultrasound or transperineal saturation biopsy), at confirmatory or follow-up biopsy. Primary outcomes were the number of Gleason score upgrades and biopsies avoided.

RESULTS

Eight confirmatory biopsy studies and three follow-up biopsy studies were included. Compared to the benchmark of using standard biopsy (SB) for all men, the addition of MRI-TB increased the detection of Gleason score upgrades at both confirmatory (6/8 studies) and follow-up biopsy (3/3 studies), with increments of 1.7-11.8 upgrades per 100 men. 6/7 studies suggested that the use of a positive mpMRI to triage men for MRI-TB or SB alone would detect fewer Gleason score upgrades than benchmark at confirmatory biopsy, but the combination of MRI-TB and SB would detect more upgrades than the benchmark. For follow-up biopsy, the evidence on mpMRI triage biopsy scenarios was inconclusive due to the small number of included studies.

CONCLUSIONS

The addition of MRI-TB to benchmark (SB for all men) maximises the detection of Gleason score upgrades at confirmatory and follow-up biopsy. When the use of mpMRI to triage men for a biopsy is desired, the combination of MRI-TB and SB should be considered for men with positive mpMRI at confirmatory biopsy. The evidence on mpMRI triage scenarios was inconclusive in the follow-up biopsy setting.

The accuracy of prostate cancer diagnosis in biopsy-naive patients using combined magnetic resonance imaging and transrectal ultrasound fusion-targeted prostate biopsy

Background

This study aimed to estimate whether multiparametric magnetic resonance imaging (mpMRI)-transrectal ultrasound (TRUS) fusion biopsy (FUS-TB) increases the detection rates of clinically significant prostate cancer (csPCa) compared with TRUS-guided systematic biopsy (TRUS-GB).

Methods

This retrospective study focused on patients who underwent mpMRI before prostate biopsy (PB) with Prostate Imaging Reporting and Data System version 2 (PI-RADS v2) scores ≥3 and prostate-specific antigen (PSA) level between 2.5 and 20 ng/mL. Before FUS-TB, the biopsy needle position was checked virtually using three-dimensional mapping. After confirming the position of the target within the prostate, biopsy needle was inserted and PB was performed. Suspicious lesions were generally targeted with 2 to 4 cores. Subsequently, 10–12 cores were biopsied for TRUS-GB. The primary endpoint was the PCa detection rate (PCDR) for patients with PCa who underwent combined FUS-TB and TRUS-GB.

Results

According to PI-RADS v2, 76.7% of the patients with PI-RADS v2 score ≥3 were diagnosed with PCa. The PCDRs in patients with PI-RADS v2 score of 4 or 5 were significantly higher than those in patients with PI-RADS v2 score of 3 (3 vs. 4, P<0.001; 3 vs. 5, P<0.001; 4 vs. 5, P=0.073). According to PCDR, the detection rates of PCa and csPCa in the FUS-TB were significantly higher than that in the TRUS-GB.

Conclusions

Following detection of suspicious tumor lesions on mpMRI, FUS-TB use detects a higher number of PCa cases compared with TRUS-GB.

Isomer-Resolved Imaging of Prostate Cancer Tissues Reveals Specific Lipid Unsaturation Profiles Associated With Lymphocytes and Abnormal Prostate Epithelia

Prostate cancer is the fourth most common cancer worldwide with definitive diagnosis reliant on biopsy and human-graded histopathology. As with other pathologies, grading based on classical haematoxylin and eosin (H&E) staining of formalin fixed paraffin-embedded material can be prone to variation between pathologists, prompting investigation of biomolecular markers. Comprising around 50% of cellular mass, and with known metabolic variations in cancer, lipids provide a promising target for molecular pathology. Here we apply isomer-resolved lipidomics in combination with imaging mass spectrometry to interrogate tissue sections from radical prostatectomy specimens. Guided by the histopathological assessment of adjacent tissue sections, regions of interest are investigated for molecular signatures associated with lipid metabolism, especially desaturation and elongation pathways. Monitoring one of the most abundant cellular membrane lipids within these tissues, phosphatidylcholine (PC) 34:1, high positive correlation was observed between the n-9 isomer (site of unsaturation 9-carbons from the methyl terminus) and epithelial cells from potential pre-malignant lesions, while the n-7 isomer abundance was observed to correlate with immune cell infiltration and inflammation. The correlation of lipid isomer signatures with human disease states in tissue suggests a future role for isomer-resolved mass spectrometry imaging in assisting pathologists with prostate cancer diagnoses and patient stratification.

Active surveillance for prostate cancer

Many men diagnosed with localized prostate cancer can postpone definitive treatment without raising their risk of metastasis or death from disease. Active surveillance (AS) is a method of monitoring select men, with the option of switching to active treatment upon signs of progression, thereby avoiding the well-known side-effects of surgery and radiotherapy. This review analyzes the data from long-running AS cohorts to determine the safety and efficacy of AS. We conducted a narrative review of recently published data, including 14 articles from 13 AS cohorts. The cohorts used varying inclusion criteria, with reported differences in clinical T stage and Gleason Score (Grade Group), among other features. Some studies (n=5) limited their cohorts to low-risk patients, while others (n=8) also included intermediate-risk patients. The heterogeneity of the cohorts produced mixed results, with the risk of prostate cancer metastasis ranging from 0.1–1.0% at 10 years and the risk of prostate cancer mortality ranging from 0–1.9% at 10 years. However, the majority of studies reported risks of less than 0.5% at 10 years for both metastasis and death. For most cohorts, half of men remained untreated for 5–10 years, with estimates ranging from 37% receiving active treatment in the Toronto cohort to 73% in the Prostate Cancer Research International AS (PRIAS) study. Current data do not support the use of negative magnetic resonance imaging (MRI) to avoid scheduled biopsy. Taken together, the data collected from these AS cohorts suggests that AS is a safe approach for men with low-grade prostate cancer and some men with intermediate risk disease. AS should be more broadly implemented for eligible patients to avoid the decreases in quality of life from undergoing active treatment. Studies expanding the inclusion criteria and further defining a subset of men with favorable intermediate-risk prostate cancer who might safely benefit from AS are needed to assess the long-term outcomes of using AS in intermediate-risk groups.

MRI-derived PRECISE scores for predicting pathologically-confirmed radiological progression in prostate cancer patients on active surveillance

OBJECTIVES

To assess the predictive value and correlation to pathological progression of the Prostate Cancer Radiological Estimation of Change in Sequential Evaluation (PRECISE) scoring system in the follow-up of prostate cancer (PCa) patients on active surveillance (AS).

METHODS

A total of 295 men enrolled on an AS programme between 2011 and 2018 were included. Baseline multiparametric magnetic resonance imaging (mpMRI) was performed at AS entry to guide biopsy. The follow-up mpMRI studies were prospectively reported by two sub-specialist uroradiologists with 10 years and 13 years of experience. PRECISE scores were dichotomized at the cut-off value of 4, and the sensitivity, specificity, positive predictive value and negative predictive value were calculated. Diagnostic performance was further quantified by using area under the receiver operating curve (AUC) which was based on the results of targeted MRI-US fusion biopsy. Univariate analysis using Cox regression was performed to assess which baseline clinical and mpMRI parameters were related to disease progression on AS.

RESULTS

Progression rate of the cohort was 13.9% (41/295) over a median follow-up of 52 months. With a cut-off value of category ≥ 4, the PRECISE scoring system showed sensitivity, specificity, PPV and NPV for predicting progression on AS of 0.76, 0.89, 0.52 and 0.96, respectively. The AUC was 0.82 (95% CI = 0.74-0.90). Prostate-specific antigen density (PSA-D), Likert lesion score and index lesion size were the only significant baseline predictors of progression (each p < 0.05).

CONCLUSION

The PRECISE scoring system showed good overall performance, and the high NPV may help limit the number of follow-up biopsies required in patients on AS.

KEY POINTS

• PRECISE scores 1-3 have high NPV which could reduce the need for re-biopsy during active surveillance. • PRECISE scores 4-5 have moderate PPV and should trigger either close monitoring or re-biopsy. • Three baseline predictors (PSA density, lesion size and Likert score) have a significant impact on the progression-free survival (PFS) time.

The role of multiparametric magnetic resonance imaging in the selection and follow-up of patients undergoing active surveillance for prostate cancer. An European Section of Uro-Technology (ESUT) review

INTRODUCTION

In recent years, active surveillance (AS) has gained popularity as a safe and reasonable option for patients with low-risk, clinically localized prostate cancer.

OBJECTIVE

To summarize the latest information regarding the use of mpMRI in the setting of active surveillance (AS) for the management of prostate cancer (PCa).

EVIDENCE ACQUISITION

A PubMed-based, English literature search was conducted through February 2020. We selected the most relevant original articles, meta-analyses and systematic reviews that could provide important information.

EVIDENCE SYNTHESIS

The great importance of mpMRI of the prostate in the setting of PCa diagnosis is its ability to visualize primarily high-grade cancerous lesions potentially missed on systematic biopsies. In several studies, mpMRI has shown an improved performance over clinically based models for identifying candidates which will benefit the most from AS. Although data on prostate mpMRI during follow-up of men under AS is sparse, it holds the probability to improve significantly AS programs by a more precise selection of optimal candidates, a more accurate identification of disease progression and a reduction in number of biopsies. The goal of reassessment of patients undergoing AS is to find the most effective moment to change attitude to active treatment.

CONCLUSION

The value of mpMRI has been recognized due to its high negative predictive value (NPV) for lesion upgrading in low-risk PCa patients. The improvement in imaging detection, and precise diagnosis with mpMRI could reduce misclassifications at initial diagnosis and during follow-up, reducing the number of biopsies.

Multiparametric MRI in Active Surveillance of Prostate Cancer: An Overview and a Practical Approach

MRI has become important for the detection of prostate cancer. MRI-guided biopsy is superior to conventional systematic biopsy in patients suspected with prostate cancer. MRI is also increasingly used for monitoring patients with low-risk prostate cancer during active surveillance. It improves patient selection for active surveillance at diagnosis, although its role during follow-up is unclear. We aim to review existing evidence and propose a practical approach for incorporating MRI into active surveillance protocols.

Diagnostic performance of MRI/TRUS fusion-guided biopsies vs. systematic prostate biopsies in biopsy-naïve, previous negative biopsy patients and men undergoing active surveillance

BACKGROUND

We aimed to assess the detection rate of overall PCa and csPCa, and the clinical impact of MRI/TRUS fusion targeted biopsy (FUSION-TB) compared to TRUS guided systematic biopsy (SB) in patients with different biopsy settings.

METHODS

Three hundred and five patients were submitted to FUSION-TB, divided into three groups: biopsy naïve patients, previous negative biopsies and patients under active surveillance (AS). All patients had a single suspicious index lesion at mpMRI. Within these groups, we enrolled men underwent both to FUSION-TB and SB in the same session. Overall detection rate of PCa and csPCa for the two biopsy methods were compared separately between the three groups of patients.

RESULTS

No differences were observed between the three groups concerning clinical and radiological characteristics. We found no differences in terms of overall PCa detection (66% vs. 63.8%, P=0.617) and csPCa detection (56.4% vs. 51.1%; P=0.225) concerning biopsy naïve patients. In patients previously submitted to a negative biopsy, FUSION-TB showed higher detection rate of csPCa compared to SB alone (41,3% vs. 27% respectively, P=0.038). In patients under AS, no differences were observed between FUSION-TB and SB in terms of overall PCa (50% vs. 73.1%) and csPCa (30.8% vs. 26.9%, respectively; P=0.705) detection.

CONCLUSIONS

Our results suggest that in men with previously negative biopsy, FUSION-TB showed significantly higher diagnostic performance for clinically significant PCa as compared to SB. Combination of FUSION-TB and SB should be recommended in AS population to offer higher chance of csPCa diagnosis.

The Utility of Combined Target and Systematic Prostate Biopsies in the Diagnosis of Clinically Significant Prostate Cancer Using Prostate Imaging Reporting and Data System Version 2 Based on Biparametric Magnetic Resonance Imaging

This study aimed to determine the predictive value of the Prostate Imaging Reporting and Data System version 2 (PI-RADS v2) based on biparametric magnetic resonance imaging (bpMRI) with combined target biopsy (TBx) and systematic biopsy (SBx) in patients with suspicion of having clinically significant prostate cancer (csPCa). In this retrospective study, we reviewed the clinical and pathological records of 184 consecutive patients who underwent bpMRI before prostate biopsy. We focused on patients with PI-RADS v2 scores ≥ 3. MRI was performed using a 3-Tesla clinical scanner with a 32-channel phased-array receiver coil. PI-RADS v2 was used to describe bpMRI findings based on T2-weighted imaging and diffusion-weighted imaging scores. The primary endpoint was the diagnostic accuracy rate of PI-RADS v2 based on bpMRI for patients with prostate cancer (PCa) who underwent combined TBx and SBx. A total of 104 patients were enrolled in this study. Combined TBx and SBx was significantly superior to either method alone for PCa detection in patients with suspicious lesions according to PI-RADS v2. TBx and SBx detected concordant csPCa in only 24.1% of the patients. In addition, the rate of increase in the Gleason score was similar between SBx (41.5%) and TBx (34.1%). The diagnostic accuracy of bpMRI is comparable to that of standard multiparametric MRI for the detection of csPCa. Moreover, combined TBx and SBx may be optimal for the accurate determination of csPCa diagnosis, the International Society of Urological Pathology grade, and risk classification.

Comparing confirmatory biopsy outcomes between MRI-targeted biopsy and standard systematic biopsy among men being enrolled in prostate cancer active surveillance

OBJECTIVES

To evaluate the ability of magnetic resonance imaging (MRI)-targeted biopsy combined with systematic biopsy (MRI-biopsy) to reduce negative biopsies and detect clinically significant prostate cancer compared to systematic biopsy (SB) alone in the confirmatory biopsy setting using matched cohorts.

PATIENTS AND METHODS

Patients were identified from an active surveillance database who had a previously positive transrectal ultrasonography-guided SB followed by a confirmatory biopsy at a single institution between 2006 and 2019. Patients were divided into two cohorts based on confirmatory biopsy technique: SB alone or MRI-biopsy (which included MRI-targeted and systematic biopsies). Cohorts were then matched on age, prostate-specific antigen (PSA) level, number of positive cores on initial biopsy and initial biopsy Gleason grade group (GG). Logistic regression was performed to identify associations with confirmatory biopsy upgrading.

RESULTS

After matching, 514 patients were identified (257 per cohort). PSA, prostate volume and PSA density prior to initial biopsy, in addition to total number of initial biopsy positive cores and GG, were similar between the matched cohorts. After confirmatory biopsy, 118/257 patients (45.9%) in the MRI-biopsy cohort were upgraded compared to 46/257 patients (17.9%) in the SB cohort (P < 0.001). The rate of negative confirmatory biopsy was 32/257 (12.5%) compared to 97/257 (37.7%) in the MRI-biopsy and SB cohorts, respectively (P < 0.001). Confirmatory MRI-biopsy was associated with greater odds of confirmatory biopsy upgrade from GG 1 to ≥GG 2 compared to SB alone (odds ratio 3.62, 95% confidence interval 1.97-6.63; P < 0.001).

CONCLUSION

The addition of MRI-targeted biopsies to SB in the confirmatory biopsy setting among men with previously detected prostate cancer resulted in fewer negative confirmatory biopsies and detection of more clinically significant prostate cancer compared to SB alone.

Diagnosis of Prostate Cancer in Patients with Prostate-Specific Antigen (PSA) in the Gray Area: Construction of 2 Predictive Models

Background

Two diagnostic models of prostate cancer (PCa) and clinically significant prostate cancer (CS-PCa) were established using clinical data of among patients whose prostate-specific antigen (PSA) levels are in the gray area (4.0–10.0 ng/ml).

Material/Methods

Data from 181 patients whose PSA levels were in the gray area were retrospectively analyzed, and the following data were collected: age, digital rectal examination, total PSA, PSA density (PSAD), free/total PSA (f/t PSA), transrectal ultrasound, multiparametric magnetic resonance imaging (mpMRI), and pathological reports. Patients were diagnosed with benign prostatic hyperplasia (BPH) and PCa by pathology reports, and PCa patients were separated into non-clinically significant PCa (NCS-PCa) and CS-PCa by Gleason score. Afterward, predictor models constructed by above parameters were researched to diagnose PCa and CS-PCa, respectively.

Results

According to the analysis of included clinical data, there were 109 patients with BPH, 44 patients with NCS-PCa, and 28 patients with CS-PCa. Regression analysis showed PCa was correlated with f/t PSA, PSAD, and mpMRI (P<0.01), and CS-PCa was correlated with PSAD and mpMRI (P<0.01). The area under the receiver operating characteristic curves of 2 models for PCa (sensitivity=73.64%, specificity=64.23%) and for CS-PCa (sensitivity=71.41%, specificity=81.82%) were 0.79 and 0.87, respectively.

Conclusions

The prediction models had satisfactory diagnostic value for PCa and CS-PCa among patients with PSA in the gray area, and use of these models may help reduce overdiagnosis.

Update on Multiparametric Prostate MRI During Active Surveillance: Current and Future Trends and Role of the PRECISE Recommendations

Active surveillance for low-to-intermediate risk prostate cancer is a conservative management approach that aims to avoid or delay active treatment until there is evidence of disease progression. In recent years, multiparametric MRI (mpMRI) has been increasingly used in active surveillance and has shown great promise in patient selection and monitoring. This has been corroborated by publication of the Prostate Cancer Radiologic Estimation of Change in Sequential Evaluation (PRECISE) recommendations, which define the ideal reporting standards for mpMRI during active surveillance. The PRECISE recommendations include a system that assigns a score from 1 to 5 (the PRECISE score) for the assessment of radiologic change on serial mpMRI scans. PRECISE scores are defined as follows: a score of 3 indicates radiologic stability, a score of 1 or 2 denotes radiologic regression, and a score of 4 or 5 indicates radiologic progression. In the present study, we discuss current and future trends in the use of mpMRI during active surveillance and illustrate the natural history of prostate cancer on serial scans according to the PRECISE recommendations. We highlight how the ability to classify radiologic change on mpMRI with use of the PRECISE recommendations helps clinical decision making.

Multiparametric magnetic resonance imaging facilitates reclassification during active surveillance for prostate cancer

OBJECTIVE

To investigate the utility of multiparametric magnetic resonance imaging (mpMRI) in the reassessment and monitoring of patients on active surveillance (AS) for Grade Group (GG) 1 prostate cancer (PCa).

PATIENTS AND METHODS

We identified, from our prospectively maintained institutional review board-approved database, 181 consecutive men enrolled on AS for GG 1 PCa who underwent at least one surveillance mpMRI followed by MRI/prostate biopsy (PBx). A subset analysis was performed among 68 patients who underwent serial (at least two) mpMRI/PBx during AS. Pathological progression (PP) was defined as upgrade to GG ≥2 on follow up biopsy.

RESULTS

Baseline MRI was performed in 34 patients (19%). At a median follow-up of 2.2 years for the overall cohort, the PP was 12% (6/49) for Prostate Imaging Reporting and Data System (PI-RADS) 1-2 lesions and 37% (48/129) for the PI-RADS ≥3 lesions. The 2-year PP-free survival rate was 84%. Surveillance prostate-specific antigen density (P < 0.001) and surveillance PI-RADS ≥3 (P = 0.002) were independent predictors of PP on reassessment MRI/PBx. In the serial MRI cohort, the 2-year PP-free survival was 95% for the No-MRI-progression group vs 85% for the MRI-progression group (P = 0.02). MRI progression was significantly higher in the PP (62%) than in the No-PP (31%) group (P = 0.04). If serial MRI were used for PCa surveillance and biopsy were triggered based only on MRI progression, 63% of PBx might be postponed at the cost of missing 12% of GG ≥2 PCa in those with stable MRI. Conversely, this strategy would miss 38% of those with upgrading to GG ≥2 PCa on biopsy. Stable serial mpMRI correlates with no reclassification to GG ≥3 PCa during AS.

CONCLUSION

On surveillance mpMRI, PI-RADS ≥3 was associated with increased risk of PCa reclassification. Surveillance biopsy based only on MRI progression may avoid a large number of biopsies at the cost of missing many PCa reclassifications.

Clinically significant prostate cancer detection and segmentation in low-risk patients using a convolutional neural network on multi-parametric MRI

OBJECTIVES

To develop an automatic method for identification and segmentation of clinically significant prostate cancer in low-risk patients and to evaluate the performance in a routine clinical setting.

METHODS

A consecutive cohort (n = 292) from a prospective database of low-risk patients eligible for the active surveillance was selected. A 3-T multi-parametric MRI at 3 months after inclusion was performed. Histopathology from biopsies was used as reference standard. MRI positivity was defined as PI-RADS score ≥ 3, histopathology positivity was defined as ISUP grade ≥ 2. The selected cohort contained four patient groups: (1) MRI-positive targeted biopsy-positive (n = 116), (2) MRI-negative systematic biopsy-negative (n = 55), (3) MRI-positive targeted biopsy-negative (n = 113), (4) MRI-negative systematic biopsy-positive (n = 8). Group 1 was further divided into three sets and a 3D convolutional neural network was trained using different combinations of these sets. Two MRI sequences (T2w, b = 800 DWI) and the ADC map were used as separate input channels for the model. After training, the model was evaluated on the remaining group 1 patients together with the patients of groups 2 and 3 to identify and segment clinically significant prostate cancer.

RESULTS

The average sensitivity achieved was 82-92% at an average specificity of 43-76% with an area under the curve (AUC) of 0.65 to 0.89 for different lesion volumes ranging from > 0.03 to > 0.5 cc.

CONCLUSIONS

The proposed deep learning computer-aided method yields promising results in identification and segmentation of clinically significant prostate cancer and in confirming low-risk cancer (ISUP grade ≤ 1) in patients on active surveillance.

KEY POINTS

• Clinically significant prostate cancer identification and segmentation on multi-parametric MRI is feasible in low-risk patients using a deep neural network. • The deep neural network for significant prostate cancer localization performs better for lesions with larger volumes sizes (> 0.5 cc) as compared to small lesions (> 0.03 cc). • For the evaluation of automatic prostate cancer segmentation methods in the active surveillance cohort, the large discordance group (MRI positive, targeted biopsy negative) should be included.

A multi‐institutional randomized controlled trial comparing first‐generation transrectal high‐resolution micro‐ultrasound with conventional frequency transrectal ultrasound for prostate biopsy

Objectives

To study high‐frequency 29 MHz transrectal side‐fire micro‐ultrasound (micro‐US) for the detection of clinically significant prostate cancer (csPCa) on prostate biopsy, and validate an image interpretation protocol for micro‐US imaging of the prostate.

Materials and methods

A prospective randomized clinical trial was performed where 1676 men with indications for prostate biopsy and without known prostate cancer were randomized 1:1 to micro‐US vs conventional end‐fire ultrasound (conv‐US) transrectal‐guided prostate biopsy across five sites in North America. The trial was split into two phases, before and after training on a micro‐US image interpretation protocol that was developed during the trial using data from the pre‐training micro‐US arm. Investigators received a standardized training program mid‐trial, and the post‐training micro‐US data were used to examine the training effect.

Results

Detection of csPCa (the primary outcome) was no better with the first‐generation micro‐US system than with conv‐US in the overall population (34.6% vs 36.6%, respectively, P = .21). Data from the first portion of the trial were, however, used to develop an image interpretation protocol termed PRI‐MUS in order to address the lack of understanding of the appearance of cancer under micro‐US. Micro‐US sensitivity in the post‐training group improved to 60.8% from 24.6% (P < .01), while specificity decreased (from 84.2% to 63.2%). Detection of csPCa in the micro‐US arm increased by 7% after training (32% to 39%, P < .03), but training instituted mid‐trial did not affect the overall results of the comparison between arms.

Conclusion

Micro‐US provided no clear benefit over conv‐US for the detection of csPCa at biopsy. However, it became evident during the trial that training and increasing experience with this novel technology improved the performance of this first‐generation system.

In this work high‐frequency 29 MHz transrectal side‐fire micro‐ultrasound (US) for the detection of clinically significant prostate cancer on prostate biopsy is studied, and an image interpretation protocol for micro‐US imaging of the prostate is validated.

The YouTube link is here: https://youtu.be/U2Svj-4Ae_k

Role of Multiparametric Prostate Magnetic Resonance Imaging before Confirmatory Biopsy in Assessing the Risk of Prostate Cancer Progression during Active Surveillance

Objective

To evaluate the impact of multiparametric magnetic resonance imaging (mpMRI) before confirmatory prostate biopsy in patients under active surveillance (AS).

Materials and Methods

This retrospective study included 170 patients with Gleason grade 6 prostate cancer initially enrolled in an AS program between 2011 and 2019. Prostate mpMRI was performed using a 1.5 tesla (T) magnetic resonance imaging system with a 16-channel phased-array body coil. The protocol included T1-weighted, T2-weighted, diffusion-weighted, and dynamic contrast-enhanced imaging sequences. Uroradiology reports generated by a specialist were based on prostate imaging-reporting and data system (PI-RADS) version 2. Univariate and multivariate analyses were performed based on regression models.

Results

The reclassification rate at confirmatory biopsy was higher in patients with suspicious lesions on mpMRI (PI-RADS score ≥ 3) (n = 47) than in patients with non-suspicious mpMRIs (n = 61) and who did not undergo mpMRIs (n = 62) (66%, 26.2%, and 24.2%, respectively; p < 0.001). On multivariate analysis, presence of a suspicious mpMRI finding (PI-RADS score ≥ 3) was associated (adjusted odds ratio: 4.72) with the risk of reclassification at confirmatory biopsy after adjusting for the main variables (age, prostate-specific antigen density, number of positive cores, number of previous biopsies, and clinical stage). Presence of a suspicious mpMRI finding (adjusted hazard ratio: 2.62) was also associated with the risk of progression to active treatment during the follow-up.

Conclusion

Inclusion of mpMRI before the confirmatory biopsy is useful to stratify the risk of reclassification during the biopsy as well as to evaluate the risk of progression to active treatment during follow-up.

EAU-EANM-ESTRO-ESUR-SIOG Guidelines on Prostate Cancer-2020 Update. Part 1: Screening, Diagnosis, and Local Treatment with Curative Intent

OBJECTIVE

To present a summary of the 2020 version of the European Association of Urology (EAU)-European Association of Nuclear Medicine (EANM)-European Society for Radiotherapy and Oncology (ESTRO)-European Society of Urogenital Radiology (ESUR)-International Society of Geriatric Oncology (SIOG) guidelines on screening, diagnosis, and local treatment of clinically localised prostate cancer (PCa).

EVIDENCE ACQUISITION

The panel performed a literature review of new data, covering the time frame between 2016 and 2020. The guidelines were updated and a strength rating for each recommendation was added based on a systematic review of the evidence.

EVIDENCE SYNTHESIS

A risk-adapted strategy for identifying men who may develop PCa is advised, generally commencing at 50 yr of age and based on individualised life expectancy. Risk-adapted screening should be offered to men at increased risk from the age of 45 yr and to breast cancer susceptibility gene (BRCA) mutation carriers, who have been confirmed to be at risk of early and aggressive disease (mainly BRAC2), from around 40 yr of age. The use of multiparametric magnetic resonance imaging in order to avoid unnecessary biopsies is recommended. When a biopsy is performed, a combination of targeted and systematic biopsies must be offered. There is currently no place for the routine use of tissue-based biomarkers. Whilst prostate-specific membrane antigen positron emission tomography computed tomography is the most sensitive staging procedure, the lack of outcome benefit remains a major limitation. Active surveillance (AS) should always be discussed with low-risk patients, as well as with selected intermediate-risk patients with favourable International Society of Urological Pathology (ISUP) 2 lesions. Local therapies are addressed, as well as the AS journey and the management of persistent prostate-specific antigen after surgery. A strong recommendation to consider moderate hypofractionation in intermediate-risk patients is provided. Patients with cN1 PCa should be offered a local treatment combined with long-term hormonal treatment.

CONCLUSIONS

The evidence in the field of diagnosis, staging, and treatment of localised PCa is evolving rapidly. The 2020 EAU-EANM-ESTRO-ESUR-SIOG guidelines on PCa summarise the most recent findings and advice for their use in clinical practice. These PCa guidelines reflect the multidisciplinary nature of PCa management.

PATIENT SUMMARY

Updated prostate cancer guidelines are presented, addressing screening, diagnosis, and local treatment with curative intent. These guidelines rely on the available scientific evidence, and new insights will need to be considered and included on a regular basis. In some cases, the supporting evidence for new treatment options is not yet strong enough to provide a recommendation, which is why continuous updating is important. Patients must be fully informed of all relevant options and, together with their treating physicians, decide on the most optimal management for them.

Combined MRI-targeted Plus Systematic Confirmatory Biopsy Improves Risk Stratification for Patients Enrolling on Active Surveillance for Prostate Cancer

OBJECTIVE

To evaluate the efficacy of combined MRI-targeted plus systematic 12-core biopsy (Cbx) to aid in the selection of patients for active surveillance (AS).

METHODS

From July 2007 to January 2020, patients with Gleason Grade Group (GG) 1 or GG 2 prostate cancer were referred to our center for AS consideration. All patients underwent an MRI and confirmatory combined MRI-targeted plus systematic biopsy (Cbx), and AS outcomes based on Cbx results were compared. Cox regression was used to identify predictors of AS failure, defined as progression to ≥ GG3 disease on follow-up biopsies.

RESULTS

Of 579 patients referred for AS, 79.3% (459/579) and 20.7% (120/579) had an initial diagnosis of GG1 and GG2 disease, respectively. Overall, 43.2% of patients (250/579) were upgraded on confirmatory Cbx, with 19.2% (111/579) upgraded to ≥ GG3. For the 226 patients followed on AS, 32.7% (74/226) had benign, 45.6% (103/226) had GG1, and 21.7% (49/226) had GG2 results on confirmatory Cbx. In total, 28.8% (65/226) of patients eventually progressed to ≥ GG3, with a median time to AS failure of 89 months. The median time from confirmatory Cbx to AS failure for the negative, GG1, and GG2 groups were 97, 97, and 32 months, respectively (p < .001). On multivariable regression, only age (hazard ratio 1.06 [1.02-1.11], p < .005) and GG on confirmatory Cbx (hazard ratio 2.75 [1.78-4.26], p < .005) remained as positive predictors of AS failure.

CONCLUSION

The confirmatory combined MRI-targeted plus systematic biopsy provides useful information for the risk stratification of patients at the time of AS enrollment.

Natural history of prostate cancer on active surveillance: stratification by MRI using the PRECISE recommendations in a UK cohort

Objectives

The PRECISE recommendations for magnetic resonance imaging (MRI) in patients on active surveillance (AS) for prostate cancer (PCa) include repeated measurement of each lesion, and attribution of a PRECISE radiological progression score for the likelihood of clinically significant change over time. We aimed to compare the PRECISE score with clinical progression in patients who are managed using an MRI-led AS protocol.

Methods

A total of 553 patients on AS for low- and intermediate-risk PCa (up to Gleason score 3 + 4) who had two or more MRI scans performed between December 2005 and January 2020 were included. Overall, 2161 scans were retrospectively re-reported by a dedicated radiologist to give a PI-RADS v2 score for each scan and assess the PRECISE score for each follow-up scan. Clinical progression was defined by histological progression to ≥ Gleason score 4 + 3 (Gleason Grade Group 3) and/or initiation of active treatment. Progression-free survival was assessed using Kaplan-Meier curves and log-rank test was used to assess differences between curves.

Results

Overall, 165/553 (30%) patients experienced the primary outcome of clinical progression (median follow-up, 74.5 months; interquartile ranges, 53–98). Of all patients, 313/553 (57%) did not show radiological progression on MRI (PRECISE 1–3), of which 296/313 (95%) had also no clinical progression. Of the remaining 240/553 patients (43%) with radiological progression on MRI (PRECISE 4–5), 146/240 (61%) experienced clinical progression (p < 0.0001). Patients with radiological progression on MRI (PRECISE 4-5) showed a trend to an increase in PSA density.

Conclusions

Patients without radiological progression on MRI (PRECISE 1-3) during AS had a very low likelihood of clinical progression and many could avoid routine re-biopsy.

Key Points

• Patients without radiological progression on MRI (PRECISE 1–3) during AS had a very low likelihood of clinical progression and many could avoid routine re-biopsy.

• Clinical progression was almost always detectable in patients with radiological progression on MRI (PRECISE 4–5) during AS.

• Patients with radiological progression on MRI (PRECISE 4–5) during AS showed a trend to an increase in PSA density.

Electronic supplementary material

The online version of this article (10.1007/s00330-020-07256-z) contains supplementary material, which is available to authorized users.

Adding systematic biopsy to magnetic resonance ultrasound fusion targeted biopsy of the prostate in men with previous negative biopsy or enrolled in active surveillance programs: A prospective single center, randomized study

Magnetic resonance imaging (MRI) targeted biopsy (TBx) of the prostate demonstrated to improve detection rate (DR) of clinically significant prostate cancer (csPCa) in biopsy-naive patients achieving strong level of evidence. Nevertheless, the csPCa yield for TBx alone versus TBx plus systematic biopsy (SBx) after accounting for overlapping of SBx cores with TBx cores, in prior-negative or active surveillance (AS) patients has not been well established.The objective of the study was to investigate benefits in terms of detection rate and pathological stratification of prostate cancer (PCa) using contextual SBx during MRI-TBx.Patients previously submitted to negative-SBx (cohort A) and those enrolled in an AS program (cohort B) who showed at least 1 suspicious area with a PIRADSv2 score ≥ 3 were prospectively and randomly assigned to only TBx strategy versus TBx plus SBx strategy. SBx locations could not encompass the TBx sites, so that the results of each type of biopsy were independent and did not overlap.A total of 312 patients were included in the 2 cohorts (cohort A: 213 cases; cohort B: 99 cases). No significant differences were found in terms of overall PCa-DR (77.6% vs 69.6% respectively; P = .36) and csPCa-DR (48.2% vs 60.9 respectively; P = .12). The MRI-TBx alone cohort showed higher csPCa/PCa ratio (87.5% vs 62.2%; P = .03). The MRI-TBx plus SBx group subanalysis showed significantly higher csPCa-DR obtained at the MRI-TBx cores when compared with the SBx cores (43.7% vs 24.1%, respectively; P = .01). Independently to age, prostatic-specific antigen and prostate imaging-reporting and data system score, either in rebiopsy (OR 0.43, 0.21-0.97) or AS (OR 0.46, 0.32-0.89) setting, SBx cores were negatively associated with the csPCa-DR when combined to TBx cores.MRI-TBx should be considered the elective method to perform prostate biopsy in patients with previous negative SBx and those considered for an AS program. Adding SBx samples to MRI-TBx did not improve detection rate of csPCa.

MRI-targeted prostate biopsy: key considerations for pathologists

We discuss the role of the pathologist for MRI-targeted prostate biopsy with a focus on specimen processing, reporting of pathological findings and quality assurance in establishing a successful MRI-targeted biopsy programme. The authors discuss the current issues relevant to pathologists regarding MRI-targeted prostate biopsy. In addition, a brief review of the recently published literature was performed using an English literature search on PubMed with a focus on original investigations related to MRI-targeted prostate biopsy. Our search terms included the following: 'prostate cancer', 'pathology', 'histology', 'reporting', 'cores', 'imaging', 'MRI' and 'mpMRI'. Prostate multiparametric magnetic resonance imaging (mp-MRI) and MRI-targeted biopsy has been shown to improve the diagnosis of clinically significant prostatic adenocarcinoma and can affect the management of patients with prostate cancer. The current active surveillance guidelines were based on data from TRUS biopsies and not MRI-targeted biopsies. MRI-targeted biopsy acquires multiple cores of tissue from one or more suspicious lesions found on mp-MRI. The way in which multiple targeted core biopsies obtained from a single image-directed region of interest are analysed and reported can potentially alter the Gleason score and tumour burden as reported on biopsy, which could undoubtedly alter patient management. Pathologists play an important role in the reporting of MRI-targeted prostate biopsies. How we report prostate cancer grade and extent on these biopsies can influence patient management. In addition, the pathologist should be involved in the quality assurance for patients undergoing MRI-targeted prostate biopsy.

The role of MRI/TRUS fusion biopsy in the diagnosis of clinically significant prostate cancer

Background

The aim of this work is to evaluate the detection rate of magnetic resonance imaging/transrectal ultrasound (MRI/TRUS) fusion-guided biopsy for clinically significant prostate cancers (Cs PCas), with particular interest in biopsy-naive patients and patients in active surveillance. MRI-targeted biopsy improves cancer detection rate (DR) in patients with prior negative biopsies; the current literature focuses on biopsy naive patients. We also evaluated the pathologic concordance between biopsies and surgical specimens.

Methods

MRI/TRUS fusion-guided biopsies were performed between February 2016 and February 2019. Patients with previous negative biopsies, biopsy-naive or in active surveillance (AS) were included. Cs PCas were defined through Epstein's criteria.

Results

A total of 416 men were enrolled. The overall DRs and Cs PCa DRs were 49% and 34.3%, respectively. Cs PCas were 17.2%, 44.9% and 73.4%, respectively for PI-RADS 3, 4 or 5. Among biopsy-naive patients, 34.8% were found to have a Cs PCa, while a 43.6% tumour upgrading was achieved in men with a low risk of PCa. In patients who underwent radical prostatectomy (RP), the concordance between biopsy Gleason score (GS) (bGS) and pathological GS (pGS) was 90.8%.

Conclusion

Our study highlights the role of MRI/TRUS fusion prostate biopsy in the detection of PCa in patients with previous negative biopsies focusing on Cs PCa diagnosis. The MRI/TRUS fusion biopsy is also emerging as a diagnostic tool in biopsy-naïve patients and deserves a fundamental role in AS protocols. A greater concordance between bGS and pGS can be achieved with targeted biopsies.