Evolution of repeat prostate biopsy strategies incorporating transperineal and MRI–TRUS fusion techniques

Role of Perilesional Sampling of Patients Undergoing Fusion Prostate Biopsies

Recently, researchers have proposed perilesional sampling during prostate biopsies to avoid systematic biopsies of patients at risk of prostate cancer. The aim of our study is to evaluate the role of perilesional sampling to avoid systematic biopsies of patients undergoing fusion biopsies. A prospective cohort of patients undergoing transrectal MRI transrectal fusion biopsies were consecutively enrolled. All the patients underwent systematic biopsies (SB), targeted biopsies (TB) and perilesional biopsies within 10 mm from the lesion (PB). The detection rates of different strategies were determined. A total of 262 patients were enrolled. The median age of those enrolled was 70 years. The mean BMI was 27 kg/m2, and the mean and prostate volume was 52 mL. A PIRADS score ≥ 4 was recorded in 163/262 (40%) patients. Overall, the detection rates of cancer were 43.5% (114/262) and 35% (92/262) for csPCa. The use of the target + peri-target strategy resulted in a detection of 32.8% (86/262) of cancer cases and of 29% (76/262) of csPCa cases (Grade Group > 2). Using the target plus peri-target approach resulted in us missing 18/262 (7%) of the csPCa cases, avoiding the diagnosis of 8/262 (3%) of nsPCa cases. A biopsy strategy including lesional and perilesional sampling could avoid unnecessary prostate biopsies. However, the risk of missing significant cancers is present. Future studies should assess the cost-benefit relationship of different strategies.

Diagnostic accuracy of bi-parametric magnetic resonance imaging in suspected prostate cancer: Correlation of scan results with biopsy findings in a series of 266 patients

Objectives:

This study aimed to determine the diagnostic accuracy of bi-parametric magnetic resonance imaging (bpMRI) for clinically significant (CS) prostate cancer (PCa), and to assess the suitability of a new diagnostic pathway using bpMRI and prostate-specific antigen density (PSAd) to determine the need for biopsy.

Methods:

A total of 386 patients referred to one UK cancer centre with suspected PCa across 12 months from 2017 to 2018 underwent bpMRI, with a Prostate Imaging Reporting and Data System (PIRADS) score assigned. Of these, 266 (69%) were biopsied, with 150 CS-PCa (a Gleason score of 7 or a Gleason score of 3 with core length ⩾5 mm) detected: a 57% diagnostic yield. Imaging, PSAd and biopsy results were collated, and a confusion matrix was calculated.

Results:

Twenty-three men with PIRADS 1 were biopsied, with two CS-PCa detected: PSAd M=0.19 ( SD=0.07). Twenty-one men with PIRADS 2 lesions were biopsied, with one CS-PCa detected: PSAd was 0.28. Seventy-five men with PIRADS 3 were biopsied, with 25 CS-PCa detected: PSAd M=0.26 ( SD=0.16). Fifty-seven men with PIRADS 4 were biopsied, with 46 CS-PCa detected: PSAd M=0.26 ( SD=0.16). Ninety men with PIRADS 5 were biopsied, with 83 CS-PCa detected: PSAd M=0.55 ( SD=0.63). Among the 266 biopsied patients, a pathway offering biopsy if PIRADS is ⩾3 or PSAd ⩾0.1 spares 11 (4.2%) biopsies compared to baseline practice, with a sensitivity of 100% and a specificity of 10.1%, for biopsy-detected CS-PCa. The diagnostic yield is 61.8%.

Conclusion:

BpMRI is comparable to multi-parametric MRI for assessing need for biopsy in suspected PCa, albeit with lower specificity. A diagnostic pathway using bpMRI and PSAd can be safely used to avoid biopsy in men at low risk, increasing diagnostic yield of biopsy while reducing overdiagnosis and avoiding the risks and costs associated with gadolinium contrast.

Level of evidence:

Level 4.

Rotterdam mobile phone app including MRI data for the prediction of prostate cancer: A multicenter external validation

OBJECTIVES

The Rotterdam Prostate Cancer Risk calculator (RPCRC) has been validated in the past years. Recently a new version including multiparametric magnetic resonance imaging (mpMRI) data has been released. The aim of our study was to analyze the performance of the mpMRI RPCRC app.

METHODS

A series of men undergoing prostate biopsies were enrolled in eleven Italian centers. Indications for prostate biopsy included: abnormal Prostate specific antigen levels (PSA>4 ng/ml), abnormal DRE and abnormal mpMRI. Patients' characteristics were recorded. Prostate cancer (PCa) risk and high-grade PCa risk were assessed using the RPCRC app. The performance of the mpMRI RPCRC in the prediction of cancer and high-grade PCa was evaluated using receiver operator characteristics, calibration plots and decision curve analysis.

RESULTS

Overall, 580 patients were enrolled: 404/580 (70%) presented PCa and out of them 224/404 (55%) presented high-grade PCa. In the prediction of cancer, the RC presented good discrimination (AUC = 0.74), poor calibration (p = 0.01) and a clinical net benefit in the range of probabilities between 50 and 90% for the prediction of PCa (Fig. 1). In the prediction of high-grade PCa, the RC presented good discrimination (AUC = 0.79), good calibration (p = 0.48) and a clinical net benefit in the range of probabilities between 20 and 80% (Fig. 1).

CONCLUSIONS

The Rotterdam prostate cancer risk App accurately predicts the risk of PCa and particularly high-grade cancer. The clinical net benefit is wide for high-grade cancer and therefore its implementation in clinical practice should be encouraged. Further studies should assess its definitive role in clinical practice.

The role of immune PSA complex (iXip) in the prediction of prostate cancer

PURPOSE

To analyse the performance of iXip in the prediction of prostate cancer (PCa) and high-grade PCa.

METHODS

A consecutive series of men undergoing MRI/FUSION prostate biopsies were enrolled in one centre. Indications for prostate biopsy included abnormal prostate-specific antigen (PSA) levels (PSA > 4 ng/ml) and/or abnormal digital rectal examination (DRE) and/or abnormal MRI. All patients underwent the evaluation of serum PSA-IgM concentration and the iXip ratio was calculated. Accuracy iXip for the prediction of PCa was evaluated using multivariable binary regression analysis and receiver operator characteristics (ROC) curves.

RESULTS

Overall 160 patients with a median age of 65 (62/73) years were enrolled. Overall, 42% patients were diagnosed with PCa and 75% of them had high-grade cancer (Epstein ≥ 3). Patients with PCa were older and presented higher PSA levels, higher PIRADS scores and lower prostate volumes (PVs). On ROC analysis iXip presented an area under the curve (AUC) of 0.57 in the prediction of PCa and of 0.54 for the prediction of high-grade PCa.

CONCLUSIONS

In our experience, immune PSA complexes are not predictors of PCa. iXip analysis should not be included in the diagnostic pathway of patients at increased risk of PCa.

The role of metabolic syndrome in high grade prostate cancer: development of a clinical nomogram

BACKGROUND

The aim of our study is to develop a clinical nomogram including metabolic syndrome status for the prediction of high-grade prostate cancer (HG PCa).

METHODS

A series of men at increased risk of PCa undergoing prostate biopsies were enrolled in a single center. Demographic and clinical characteristics of the patients were recorded. Metabolic syndrome was defined according to the adult treatment panel III. A nomogram was generated based on the logistic regression model and used to predict high grade prostate cancer defined as grade group ≥3 (ISUP 2014). ROC curves, calibration plots and decision curve analysis were used to evaluate the performance of the nomogram.

RESULTS

Overall, 738 patients were enrolled. Greater than or equal to 294/738 (40%) of the patients presented PCa and of those patients, 84/294 (39%) presented high grade disease (Grade Group ≥3). On multivariate analysis, DRE (OR: 3.24, 95% CI: 1.80-5.84), PSA (OR: 1.10, 95% CI: 1.05-1.16), PV (OR: 0.98, 95% CI: 0.97-0.99) and MetS (OR: 2.02, 95% CI: 1.13-3.59) were predictors of HG PCa. The nomogram based on the model presented good discrimination (AUC: 0.76), good calibration (Hosmer-Lemeshow Test, P>0.05) and a net benefit in the range of probabilities between 10% and 70%.

CONCLUSIONS

Metabolic syndrome is highly prevalent in patients at risk of prostate cancer and is particularly associated with high-grade prostate cancer. Our nomogram offers the possibility to include metabolic status in the assessment of patients at risk of prostate cancer to identify men who may have a high-grade form of the disease. External validation is warranted before its clinical implementation.

The role of magnetic resonance imaging-guided biopsy for diagnosis of prostate cancer; comparison between FUSION and "IN-BORE" approaches

BACKGROUND

The aim of the present study is to evaluate the difference in terms of feasibility and detection rate of two magnetic resonance imaging (MRI) guided biopsy approaches (MRI fusion versus "in-bore" MRI) in a single tertiary center.

METHODS

We retrospectively identified 297 patients with suspected prostate cancer who underwent MRI based target prostate biopsy (FUSION or "in-bore" approaches) between January 2016 and January 2018 in a single tertiary center.

RESULTS

Lesion site (peripheral vs. central) and localization (anterior vs. posterior) were equally comparable among two groups, but maximum diameter of multiparametric-MRI Index lesion was slightly superior in the in-bore MRI-GB group (14 vs. 12 mm, P=0.002). Mean random biopsy cores taken were 11.2±2.1, with 1.3±2 positive cores in FUSION-GB group. Mean number of targeted biopsy cores taken was significantly superior in the FUSION-GB group as compared to the in-bore MRI-GB group (2.6±0.7 vs.1.7±1, P<0.001), whereas mean number of positive targeted biopsy cores was comparable between two groups (1±1.3 vs.1±0.9, P=0.1). 70 (45.5%) and 75 (52.8%) patients had positive targeted bioptic cores at pathologic examination among FUSION-GB and in-bore MRI-GB groups, respectively (P=0.2). Bioptical ISUP grade was also comparable among two groups (P=0.2) in multivariate analysis PI-RADS Score (OR=3.04 and OR=8.32 for PI-RADS 4 and 5, respectively) and PSA density (OR=2.69) were identified as independent predictors of positive targeted cores at histological examination (P<0.001 and P=0.01, respectively).

CONCLUSIONS

In-bore MRI-GB approaches represent a promising technique that may offer some advantages compared to standard systematic FUSION-GB despite higher costs of in bore-procedure. Our experience, although not showing a clear advantage between the FUSION technique and the "in-bore" technique, resulted safe and feasible and represents a viable procedure for the diagnosis and characterization of prostate especially in a subgroup of patient with clinically significant disease. Further investigations are needed in order to identify the best approach for MRI-GB.

The Cambridge Prognostic Groups for improved prediction of disease mortality at diagnosis in primary non-metastatic prostate cancer: a validation study

BACKGROUND

The purpose of this study is to validate a new five-tiered prognostic classification system to better discriminate cancer-specific mortality in men diagnosed with primary non-metastatic prostate cancer.

METHODS

We applied a recently described five-strata model, the Cambridge Prognostic Groups (CPGs 1-5), in two international cohorts and tested prognostic performance against the current standard three-strata classification of low-, intermediate- or high-risk disease. Diagnostic clinico-pathological data for men obtained from the Prostate Cancer data Base Sweden (PCBaSe) and the Singapore Health Study were used. The main outcome measure was prostate cancer mortality (PCM) stratified by age group and treatment modality.

RESULTS

The PCBaSe cohort included 72,337 men, of whom 7162 died of prostate cancer. The CPG model successfully classified men with different risks of PCM with competing risk regression confirming significant intergroup distinction (p < 0.0001). The CPGs were significantly better at stratified prediction of PCM compared to the current three-tiered system (concordance index (C-index) 0.81 vs. 0.77, p < 0.0001). This superiority was maintained for every age group division (p < 0.0001). Also in the ethnically different Singapore cohort of 2550 men with 142 prostate cancer deaths, the CPG model outperformed the three strata categories (C-index 0.79 vs. 0.76, p < 0.0001). The model also retained superior prognostic discrimination in the treatment sub-groups: radical prostatectomy (n = 20,586), C-index 0.77 vs. 074; radiotherapy (n = 11,872), C-index 0.73 vs. 0.69; and conservative management (n = 14,950), C-index 0.74 vs. 0.73. The CPG groups that sub-divided the old intermediate-risk (CPG2 vs. CPG3) and high-risk categories (CPG4 vs. CPG5) significantly discriminated PCM outcomes after radical therapy or conservative management (p < 0.0001).

CONCLUSIONS

This validation study of nearly 75,000 men confirms that the CPG five-tiered prognostic model has superior discrimination compared to the three-tiered model in predicting prostate cancer death across different age and treatment groups. Crucially, it identifies distinct sub-groups of men within the old intermediate-risk and high-risk criteria who have very different prognostic outcomes. We therefore propose adoption of the CPG model as a simple-to-use but more accurate prognostic stratification tool to help guide management for men with newly diagnosed prostate cancer.

Internal Fusion: exact correlation of transrectal ultrasound images of the prostate by detailed landmarks over time for targeted biopsies or follow-up

PURPOSE

Innovative imaging modalities are applied for diagnosing and follow-up of prostate cancer (PCa). To perform authentic targeted biopsies and evaluate prostate changes, it is essential to reliably identify and hit targets in their true anatomical location over time. A newly described image correlation method (Internal Fusion) allows precise correlation of serial transrectal ultrasound (TRUS) images in vitro and vivo. Identifiable morphologic structures such as prostatic calcifications define internal anchor points (Internal Landmarks) to facilitate exact correlation.

METHODS

After verification of Internal Fusion in vitro, 83 patients were included from January to August 2017 with at least one prior series of 5-mm spaced TRUS images stored as computed tomographic (US-CT) online data set. Two experienced operators collected new images in correlation with each cross-section of the previous examinations based on Internal Landmarks.

RESULTS

Of the 83 patients, fifty (60%) had prior negative biopsies. Fourteen (17%) wished US-CT targeted biopsies and PCa were detected in 7/14 patients (50%). Overall, accurate imaging correlations were attained in 369/397 slices (93%). In initial and repeat biopsy, 31/31 and 35/35 images could be correlated detecting PCa in 5/8 (63%) and 2/6 patients (33%). The longest observation of prostate changes over time (Trend Monitoring) with accurate image correlation was 8 years and 6 months.

CONCLUSIONS

Internal Fusion by Internal Landmarks ensures exact correlation in long-term follow-up. It is possible to precisely monitor trends in prostate tissue changes. In case of PCa suspicion, biopsies could be targeted with high accuracy by Internal Fusion, even over time.

Comparing Three Different Techniques for Magnetic Resonance Imaging-targeted Prostate Biopsies: A Systematic Review of In-bore versus Magnetic Resonance Imaging-transrectal Ultrasound fusion versus Cognitive Registration. Is There a Preferred Technique?

CONTEXT

The introduction of magnetic resonance imaging-guided biopsies (MRI-GB) has changed the paradigm concerning prostate biopsies. Three techniques of MRI-GB are available: (1) in-bore MRI target biopsy (MRI-TB), (2) MRI-transrectal ultrasound fusion (FUS-TB), and (3) cognitive registration (COG-TB).

OBJECTIVE

To evaluate whether MRI-GB has increased detection rates of (clinically significant) prostate cancer (PCa) compared with transrectal ultrasound-guided biopsy (TRUS-GB) in patients at risk for PCa, and which technique of MRI-GB has the highest detection rate of (clinically significant) PCa.

EVIDENCE ACQUISITION

We performed a literature search in PubMed, Embase, and CENTRAL databases. Studies were evaluated using the Quality Assessment of Diagnostic Accuracy Studies-2 checklist and START recommendations. The initial search identified 2562 studies and 43 were included in the meta-analysis.

EVIDENCE SYNTHESIS

Among the included studies 11 used MRI-TB, 17 used FUS-TB, 11 used COG-TB, and four used a combination of techniques. In 34 studies concurrent TRUS-GB was performed. There was no significant difference between MRI-GB (all techniques combined) and TRUS-GB for overall PCa detection (relative risk [RR] 0.97 [0.90-1.07]). MRI-GB had higher detection rates of clinically significant PCa (csPCa) compared with TRUS-GB (RR 1.16 [1.02-1.32]), and a lower yield of insignificant PCa (RR 0.47 [0.35-0.63]). There was a significant advantage (p = 0.02) of MRI-TB compared with COG-TB for overall PCa detection. For overall PCa detection there was no significant advantage of MRI-TB compared with FUS-TB (p=0.13), and neither for FUS-TB compared with COG-TB (p=0.11). For csPCa detection there was no significant advantage of any one technique of MRI-GB. The impact of lesion characteristics such as size and localisation could not be assessed.

CONCLUSIONS

MRI-GB had similar overall PCa detection rates compared with TRUS-GB, increased rates of csPCa, and decreased rates of insignificant PCa. MRI-TB has a superior overall PCa detection compared with COG-TB. FUS-TB and MRI-TB appear to have similar detection rates. Head-to-head comparisons of MRI-GB techniques are limited and are needed to confirm our findings.

PATIENT SUMMARY

Our review shows that magnetic resonance imaging-guided biopsy detects more clinically significant prostate cancer (PCa) and less insignificant PCa compared with systematic biopsy in men at risk for PCa.

Investigating the ability of multiparametric MRI to exclude significant prostate cancer prior to transperineal biopsy

INTRODUCTION

We characterized false negative prostate magnetic resonance imaging (MRI) reporting by using histology derived from MRI-transrectal ultrasound (TRUS)-guided transperineal (MTTP) fusion biopsies.

METHODS

In total, 148 consecutive patients were retrospectively reviewed. Men underwent multiparametric MRI (mpMRI), reported by a consultant/attending radiologist in line with European Society of Urogenital Radiology (ESUR) standards. MTTP biopsy of the lesions was performed according to the Ginsburg recommendations. Cases with an MRI-histology mismatch were identified and underwent a second read by an experienced radiologist. A third review was performed with direct histology comparison to determine a true miss from an MRI-occult cancer. Statistical analysis was performed with McNemar's test.

RESULTS

False negative lesions were identified in 29 MRI examinations (19.6%), with a total of 46 lesions. Most false negative lesions (21/46) were located in the anterior sectors of the prostate. The second read led to a significant decrease of false-negative lesions with 7/29 further studies identified as positive on a patient-by-patient basis (24.1% of studies, p = 0.016) and 11/46 lesions (23.9%; p = 0.001). Of these, 30 lesions following the first read and 23 lesions after the second read were considered significant cancer according to the University College London criteria. However, on direct comparison with histology, most lesions were MRI occult.

CONCLUSION

We demonstrate that MRI can fail to detect clinically relevant lesions. Improved results were achieved with a second read but despite this, a number of lesions remain MRI-occult. Further advances in imaging are required to reduce false negative results.

Prebiopsy MRI and MRI-ultrasound Fusion-targeted Prostate Biopsy in Men With Previous Negative Biopsies: Impact on Repeat Biopsy Strategies

OBJECTIVE

To report outcomes of magnetic resonance imaging (MRI)-ultrasound fusion-targeted biopsy (MRF-TB) and 12-core systematic biopsy (SB) over a 26-month period in men with prior negative prostate biopsy.

MATERIALS AND METHODS

Between June 2012 and August 2014, 210 men presenting to our institution for prostate biopsy with ≥1 prior negative biopsy underwent multiparametric MRI followed by MRF-TB and SB and were entered into a prospective database. Clinical characteristics, maximum mpMRI suspicion scores (mSS), and biopsy results were queried from the database, and the detection rates of Gleason ≥7 prostate cancer (PCa) and overall PCa were compared between biopsy techniques using McNemar's test.

RESULTS

Forty seven (29%) of 161 men meeting inclusion criteria (mean age, 65 ± 8 years; mean prostate-specific antigen, 8.9 ± 8.9) were found to have PCa. MRF-TB and SB had overall cancer detection rates (CDRs) of 21.7% and 18.6% (P = .36), respectively, and CDR for Gleason score (GS) ≥7 disease of 14.9% and 9.3% (P = .02), respectively. Of 26 men with GS ≥7 disease, MRF-TB detected 24 (92.3%) whereas SB detected 15 (57.7%; P < .01). Using UCSF-CAPRA criteria, only 1 man was restratified from low risk to higher risk based on SB results compared to MRF-TB alone. Among men with mSS <4, 72% of detected cancers were low risk by UCSF-CAPRA criteria.

CONCLUSION

In men with previous negative biopsies and persistent suspicion of PCa, SB contributes little to the detection of GS ≥7 disease by MRF-TB, and avoidance of SB bears consideration. Based on the low likelihood of detecting GS ≥7 cancer and overall low-risk features of PCa in men with mSS <4, limiting biopsy to men with mSS ≥4 warrants further investigation.

Evaluation of the 'Prostate Interdisciplinary Communication and Mapping Algorithm for Biopsy and Pathology' (PIC-MABP)

INTRODUCTION

Experience from interdisciplinary cooperation revealed the need for a prostate mapping scheme to communicate multiparametric MRI (mpMRI) findings between radiologists, urologists, and pathologists, which should be detailed, yet easy to memorize. For this purpose, the 'Prostate interdisciplinary communication and mapping algorithm for biopsy and pathology' (PIC-MABP) was developed. This study evaluated the accuracy of the PIC-MABP system.

METHODS

PIC-MABP was tested and validated in findings of 10 randomly selected patients from routine clinical practise with 18 histologically proven cancer lesions. Patients received an mpMRI of the prostate prior to prostatectomy. After surgery the prostates were prepared as whole-mount step sections. Cancer lesions, which were found suspicious on mpMRI, were assigned to the according PIC-MABP sectors by a radiologist. MpMRI slides were masked and sent to seven urologists from different centres, providing only the PIC-MABP location of each lesion. Urologists marked the accordant regions. Then mpMRI slides were unmasked, and the correctness of each mark was evaluated.

RESULTS

One hundred and seventeen of the 126 marks (93%) were correctly assigned. Detection rates differed for lesions >0.5 cc compared with lesions <0.5 cc (p < 0.005): 3/7 (43%) marks were correctly assigned in lesions <0.3 cc, 16/21 (76%) in lesions with 0.3-0.5 cc, and 98/98 (100%) in lesions >0.5 cc. Interobserver agreement was good for lesions >0.5 cc and poor for lesions <0.3 cc (Fleiss Kappa 1 vs. 0.0175).

CONCLUSION

PIC-MABP seems to be a reliable system to communicate the location of mpMRI findings >0.5 cc between different disciplines and can be a useful guidance for cognitive mpMRI/TRUS fusion biopsy.