Ruling out clinically significant prostate cancer with negative multi-parametric MRI

The Utility of Transperineal Template Saturation Biopsy in the Detection of Clinically Significant Prostate Cancer

Aim: We investigated the role of transperineal template saturation biopsy (TTSB) in detecting clinically significant prostate cancer (csPCa). We compared the TTSB findings with multiparametric magnetic resonance imaging (mpMRI) findings in suspected prostate cancer patients. Methods: This retrospective study included 124 patients who underwent TTSB following mpMRI at our institute. We examined factors contributing to csPCa detection in these patients. We examined the association between the Prostate Imaging-Reporting and Data System (PI-RADS) Version 2.1 category and csPCa detection. Results: The median age at TTSB was 68 (interquartile range: 62-73) years, and the median prostate-specific antigen level was 9.9 (6.1-15.5) ng/mL. Herein, 61.3% (76/124) of the patients who underwent TTSB had cancer and 35.5% (44/124) had csPCa. Abnormal digital rectal examination findings (p=0.006) and PI-RADS category ≥ 4 (p < 0.001) were independent factors for csPCa detection. Among patients categorized as PI-RADS ≥ 4, 64.8% (35/54) had csPCa; csPCa frequency increased with increasing PI-RADS categories (p < 0.001). Cancer was detected in 38.3% (23/60) of the patients categorized as PI-RADS ≤ 2; among them, 10% (6) had csPCa. Only 3.2% (4/124) of the patients had TTSB-related adverse events ≥ grade 2, 0.8% (1/124) suffered from hematuria, and 2.4% (3/124) had acute urinary retention. All patients were treated conservatively. Conclusions: Patients with a higher PI-RADS category tended to have csPCa. However, the PI-RADS category alone may not be sufficient for csPCa detection. TTSB detected csPCa in 10% of the patients with negative mpMRI findings. TTSB is a safe and crucial technique for accurately diagnosing prostate cancer.

A Novel Nomogram to Identify Candidates for Focal Therapy Among Patients with Localized Prostate Cancer Diagnosed via Magnetic Resonance Imaging-Targeted and Systematic Biopsies: A European Multicenter Study

BACKGROUND

Suitable selection criteria for focal therapy (FT) are crucial to achieve success in localized prostate cancer (PCa).

OBJECTIVE

To develop a multivariable model that better delineates eligibility for FT and reduces undertreatment by predicting unfavorable disease at radical prostatectomy (RP).

DESIGN, SETTING, AND PARTICIPANTS

Data were retrospectively collected from a prospective European multicenter cohort of 767 patients who underwent magnetic resonance imaging (MRI)-targeted and systematic biopsies followed by RP in eight referral centers between 2016 and 2021. The Imperial College of London eligibility criteria for FT were applied: (1) unifocal MRI lesion with Prostate Imaging-Reporting and Data System score of 3-5; (2) prostate-specific antigen (PSA) ≤20 ng/ml; (3) cT2-3a stage on MRI; and (4) International Society of Urological Pathology grade group (GG) 1 and ≥6 mm or GG 2-3. A total of 334 patients were included in the final analysis.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

The primary outcome was unfavorable disease at RP, defined as GG ≥4, and/or lymph node invasion, and/or seminal vesicle invasion, and/or contralateral clinically significant PCa. Logistic regression was used to assess predictors of unfavorable disease. The performance of the models including clinical, MRI, and biopsy information was evaluated using the area under the receiver operating characteristic curve (AUC), calibration plots, and decision curve analysis. A coefficient-based nomogram was developed and internally validated.

RESULTS AND LIMITATIONS

Overall, 43 patients (13%) had unfavorable disease on RP pathology. The model including PSA, clinical stage on digital rectal examination, and maximum lesion diameter on MRI had an AUC of 73% on internal validation and formed the basis of the nomogram. Addition of other MRI or biopsy information did not significantly improve the model performance. Using a cutoff of 25%, the proportion of patients eligible for FT was 89% at the cost of missing 30 patients (10%) with unfavorable disease. External validation is required before the nomogram can be used in clinical practice.

CONCLUSIONS

We report the first nomogram that improves selection criteria for FT and limits the risk of undertreatment.

PATIENT SUMMARY

We conducted a study to develop a better way of selecting patients for focal therapy for localized prostate cancer. A novel predictive tool was developed using the prostate-specific antigen (PSA) level measured before biopsy, tumor stage assessed via digital rectal examination, and lesion size on magnetic resonance imaging (MRI) scans. This tool improves the prediction of unfavorable disease and may reduce the risk of undertreatment of localized prostate cancer when using focal therapy.

Using IsoPSA With Prostate Imaging Reporting and Data System Score May Help Refine Biopsy Decision Making in Patients With Elevated PSA

OBJECTIVE

To assess how IsoPSA, a structure-based serum assay which has been prospectively validated in detecting clinically significant prostate cancer (csPCa), can help the biopsy decision process when combined with the prostate imaging reporting and data systems (PI-RADS).

MATERIALS AND METHODS

This was a single-center retrospective review of prospectively collected data on patients receiving IsoPSA testing for elevated PSA (>4.0ng/mL). Patients were included if they had received an IsoPSA test and prostate MRI within 1 year of IsoPSA testing, and subsequently underwent prostate biopsy. Multivariable logistic regression was used to identify predictors of (csPCa, ie, GG ≥ 2) on biopsy. Predictive probabilities for csPCa at biopsy were generated using IsoPSA and various PI-RADS scores.

RESULTS

Two hundred and 7 patients were included. Twenty-two percent had csPCa. Elevated IsoPSA ratio (defined as ≥6.0) (OR: 5.06, P = .015) and a PI-RADS 4-5 (OR: 6.37, P <.001) were significant predictors of csPCa. The combination of elevated IsoPSA ratio and PI-RADS 4-5 lesion had the highest area under the curve (AUC) (AUC: 0.83, P <.001). The predicted probability of csPCa when a patient had a negative or equivocal MRI (PI-RADS 1-3) and a low IsoPSA ratio (≤6) was <5%.

CONCLUSION

The combination of PI-RADS with IsoPSA ratios may help refine the biopsy decision-making process. In our cohort, a negative or equivocal MRI with a low IsoPSA may provide a low enough predicted probability to omit biopsy in such patients.

Therapy decisions after diagnosis of prostate cancer in men with negative prostate MRI

BACKGROUND

To investigate the clinical implications of magnetic resonance imaging (MRI) negative prostate cancer (PCa) in a cohort of men undergoing transperineal prostate biopsy.

METHODS

We included all men without prior diagnosis of PCa undergoing transperineal template saturation ± fusion-guided targeted biopsy of the prostate between November 2014 and March 2018. Before biopsy, all patients underwent MRI and biopsies were performed irrespective of imaging results. Baseline characteristics, imaging, biopsy results, and follow-up information were retrieved from the patient charts. Patients were classified as either MRI negative (Prostate Imaging Reporting and Data System [PIRADS] ≤ 2) or positive (PIRADS ≥ 3). ISUP grade group 1 was defined as clinically nonsignificant (nsPCa) and ≥2 as clinically significant PCa (csPCa). Primary outcome was the individual therapeutic decision after diagnosis of PCa stratified according to MRI visibility. Secondary outcomes were the sensitivity and specificity of MRI, and the urooncological outcomes after radical prostatectomy (RP).

RESULTS

From 515 patients undergoing prostate biopsy, 171 (33.2%) patients had a negative and 344 (66.8%) a positive MRI. Pathology review stratified for MRI negative and positive cases revealed nsPCa in 27 (15.8%) and 32 (9.3%) and csPCa in 26 (15.2%) and 194 (56.4%) of the patients, respectively. The rate of active treatment in the MRI negative was lower compared with the MRI positive cohort (12.3% vs. 53.2%; odd ratio [OR] = 0.12; p < 0.001). While men with negative MRI were more likely to undergo active surveillance (AS) than MRI positive patients (18.1% vs. 10.8%; OR = 1.84; p = 0.027), they rarely underwent RP (6.4% vs. 40.7%, OR = 0.10; p < 0.001). Logistic regression revealed that a negative MRI was independently protective for active treatment (OR = 0.32, p = 0.014). The specificity, sensitivity, negative, and positive predictive value of MRI for detection of csPCa were 49.2%, 88.2%, 56.4%, and 84.8%, respectively. The rate of adverse clinicopathological outcome features (pT3/4, ISUP ≥4, or prostate-specific antigen [PSA]-persistence) following RP was 4.7% for men with MRI negative compared to 17.4% for men with MRI positive PCa (OR = 3.1, p = 0.19).

CONCLUSION

Only few men with MRI negative PCa need active cancer treatment at the time of diagnosis, while the majority opts for AS. Omitting prostate biopsies and performing a follow-up MRI may be a safe alternative to reduce the number of unnecessary interventions.

Transrectal Ultrasound in Prostate Cancer: Current Utilization, Integration with mpMRI, HIFU and Other Emerging Applications

Transrectal ultrasound (TRUS) has been an invaluable tool in the assessment of prostate size, anatomy and aiding in prostate cancer (PCa) diagnosis for decades. Emerging techniques warrant an investigation into the efficacy of TRUS, how it compares to new techniques, and options to increase the accuracy of prostate cancer diagnosis. Currently, TRUS is used to guide both transrectal and transperineal biopsy approaches with similar cancer detection rates, but lower rates of infection have been reported with the transperineal approach, while lower rates of urinary retention are often reported with the transrectal approach. Multiparametric MRI has substantial benefits for prostate cancer diagnosis and triage such as lesion location, grading, and can be combined with TRUS to perform fusion biopsies targeting specific lesions. Micro-ultrasound generates higher resolution images that traditional ultrasound and has been shown effective at diagnosing PCa, giving it the potential to become a future standard of care. Finally, high-intensity focused ultrasound focal therapy administered via TRUS has been shown to offer safe and effective short-term oncological control for localized disease with low morbidity, and the precise nature makes it a viable option for salvage and repeat therapy.

Negative multiparametric magnetic resonance imaging for prostate cancer: further outcome and consequences

PURPOSE

EAU guidelines recommend multiparametric MRI of the prostate (mpMRI) prior to biopsy to increase accuracy and reduce biopsies. Whether biopsy can be avoided in case of negative mpMRI remains unclear. Aim of this study is to evaluate predictors of overall prostate cancer (PCa) in negative mpMRI.

METHODS

A total of 216 patients from 2018 to 2020 with suspicion of PCa and negative mpMRI (PI-RADS ≤ 2) were interviewed by telephone about outcome and further follow-up. Clinically significant PCa (csPCa) was defined as ISUP ≥ 2. Patients with vs. without biopsy and with vs. without PCa were compared. Univariate and multivariate analyses were performed to evaluate predictors of PCa occurrence in patients with negative mpMRI.

RESULTS

15.7% and 5.1% of patients with PI-RADS ≤ 2 on mpMRI showed PCa and csPCa, respectively. PCa patients had higher PSAD (0.14 vs. 0.09 ng/ml²; p = 0.001) and lower prostate volume (50.5 vs. 74.0 ml; p = 0.003). Patients without biopsy (25%) after MRI were older (69 vs. 65.5 years; p = 0.027), showed lower PSA (5.7 vs. 6.73 ng/ml; p = 0.033) and lower PSA density (0.09 vs. 0.1 ng/ml²; p = 0.027). Multivariate analysis revealed age (OR 1.09 [1.02-1.16]; p = 0.011), prostate volume (OR 0.982 [0.065; 0.997]; p = 0.027), total PSA level (OR 1.22 [1.01-1.47], p = 0.033), free PSA (OR 0.431 [0.177; 0.927]; p = 0.049) and no PI-RADS lesion vs PI-RADS 1-2 lesion (OR 0.38 [0.15-0.91], p = 0.032.) as predictive factors for the endpoint presence of PCa.

CONCLUSIONS

Biopsy for selected patient groups (higher age, prostate volume and free PSA as well as lower PSA-Density) with negative mpMRI can be avoided, if sufficient follow-up care is guaranteed. Detailed counseling regarding residual risk for undetected prostate cancer should be mandatory.

Evaluation of multiparametric prostate magnetic resonance imaging findings in patients with a Gleason score of 6 in transrectal ultrasonography-guided biopsy

PURPOSE

We aimed to evaluate prostate multiparametric magnetic resonance imaging (mpMRI) findings of patients with a Gleason score (GS) of 6 and effectiveness of MRI based on the final pathology result in patients undergoing radical prostatectomy (RP).

MATERIAL AND METHODS

mpMRI findings of 80 patients who had a GS of 3 + 3 and who underwent mpMRI were evaluated retrospectively. The mpMRI were scored according to the PIRADS v2.1 guidelines. The patients were divided into those with a high probability of clinically significant cancer (CSC) (PI-RADS 4-5) and those with a low probability of CSC (PI-RADS 2-3).

RESULTS

Of the 80 patients, 33.8% had PI-RADS 2-3, and 66.2% had PI-RADS 4-5 lesions. There was a significant difference between the groups in prostate specific antigen (PSA) value, PSA density, patient age, and tumour percentage on biopsy. When the pathology results were taken as the gold standard in the group that underwent RP, sensitivity, specificity, and accuracy of mpMRI were calculated as 94.74%, 100%, and 96.3%, respectively, an increase in the final GS was found in 9 (33.3%) of the 27 patients, and 70.35% of patients were identified as having CSC.

CONCLUSIONS

PI-RADS 4-5 scores have high sensitivity and negative predictive value in the diagnosis of CSC. mpMRI is a reliable and non-invasive diagnostic method that can complement biopsy results in decision-making in patients who are initially evaluated as low risk.

Apical periurethral transition zone lesions: MRI and histology findings

PURPOSE

Apical periurethral transition zone (TZ) cancers can pose unique problems for surgery and radiation therapy. Here, we describe the appearance of such cancers on multiparametric MRI (mpMRI) and correlate this with histopathology derived from MRI-targeted biopsy.

MATERIALS AND METHODS

Between May 2011 and January 2019, a total of 4381 consecutive patients underwent 3 T mpMRI. Of these, 53 patients with 58 apical periurethral TZ lesions underwent TRUS/MRI fusion-guided biopsy and 12-core systematic TRUS-guided biopsy. Correlation was made with patient age, PSA, PSA density, whole prostate volume, and Gleason scores.

RESULTS

A total 53 men (median age 68 years, median PSA 7.94 ng/ml) were identified as having at least one apical periurethral TZ lesion on mpMRI and 5 (9%) patients had more than one apical periurethral lesion. Thus, 58 lesions were identified in 53 patients. Of these 37/53 patients (69%) and 40/58 lesions were positive at biopsy for prostate cancer. Seven were diagnosed by 12-core systematic TRUS-guided biopsy and 34 were diagnosed by TRUS/MRI fusion-guided biopsy. Gleason score was ≥ 3 + 4 in 34/58 (58%) lesions.

CONCLUSION

Identification of apical periurethral TZ prostate cancers is important to help guide surgical and radiation therapy as these tumors are adjacent to critical structures. Because of the tendency to undersample the periurethral zone during TRUS biopsy, MRI-guided biopsy is particularly helpful for detecting apical periurethral TZ prostate cancers many of which prove to be clinically significant.

What to expect from a non-suspicious prostate MRI? A review

BACKGROUND

Many guidelines now recommend multiparametric MRI (mpMRI) prior to an initial or repeat prostate biopsy. However, clinical decision making for men with a non-suspicious mpMRI (Likert or PIRADS score 1-2) varies.

OBJECTIVES

To review the most recent literature to answer three questions. (1) Should we consider systematic biopsy if mpMRI is not suspicious? (2) Are there additional predictive factors that can help decide which patient should have a biopsy? (3) Can the low visibility of some cancers be explained and what are the implications?

SOURCES

A narrative review was performed in Medline databases using two searches with the terms "MRI" and "prostate cancer" and ("diagnosis" or "biopsy") and ("non-suspicious" or "negative" or "invisible"); "prostate cancer MRI visible". References of the selected articles were screened for additional articles.

STUDY SELECTION

Studies published in the last 5 years in English language were assessed for eligibility and selected if data was available to answer one of the three study questions.

RESULTS

Considering clinically significant cancer as ISUP grade≥2, the negative predictive value (NPV) of mpMRI in various settings and populations ranges from 76% to 99%, depending on cancer prevalence and the type of confirmatory reference test used. NPV is higher among patients with prior negative biopsy (88-96%), and lower for active surveillance patients (85-90%). The PSA density (PSAd) with a threshold of PSAd<0.15ng/ml/ml was the most studied and relevant predictive factor used in combination with mpMRI to rule out clinically significant cancer. Finally, mpMRI-invisible tumours appear to differ from a histopathological and genetic point of view, conferring clinical advantage to invisibility.

LIMITATIONS

Most published data come from expert centres and results may not be reproducible in all settings.

CONCLUSION

mpMRI has high diagnostic accuracy and in cases of negative mpMRI, PSA density can be used to determine which patient should have a biopsy. Growing knowledge of the mechanisms and genetics underlying MRI visibility will help develop more accurate risk calculators and biomarkers.

Evaluating the efficacy of a low-cost cognitive MRI-targeted prostate biopsy protocol: is there still a role for lower volume centers in the Prostate Imaging Reporting and Data System (PI-RADS) version 2 era?

PURPOSE

MRI-targeted biopsy has improved prostate biopsy yield. However, cost constraints have made it difficult for many institutions to implement the newer methods. We evaluated the performance of a low-cost cognitive-targeting biopsy protocol based on 1.5 T multiparametric MRI graded with Prostate Imaging Reporting and Data System (PI-RADS) version 2 to examine the role for these institutions moving forward.

METHODS

Retrospective analysis of 251 consecutive patients with prostate-specific antigen (PSA) under 50 who underwent MRI and subsequent prostate biopsy at a single facility. In addition to systematic biopsy, targeted cores were obtained with cognitive recognition under ultrasound. A control group of 267 consecutive patients with PSA under 50 biopsied without prior MRI was analyzed.

RESULTS

Prostate biopsy preceded by MRI had a significantly higher probability of detecting both prostate cancer (68.1% vs. 51.3%) and clinically significant prostate cancer (57.4% vs. 39.7%) (p values < 0.01). Combination of systematic and targeted biopsy outperformed either regimen alone. PSA density and PI-RADS score were identified as independent risk factors, and a proposed diagnostic model (PSA density ≥ 0.25 or PI-RADS score ≥ 4) showed sensitivity of 88.6%, specificity of 55%, PPV of 81.2%, NPV of 68.8%, and accuracy of 78.0%.

CONCLUSIONS

Both pre-biopsy MRI and cognitive-targeted biopsy contributed to improvement of cancer yield. Future alterations of possible benefit included increasing target cores per lesion, and combining PI-RADS score and PSA density as indicators for biopsy. Similar protocols may represent an on-going role for lower volume centers in the diagnosis of prostate cancer.

Prospective Evaluation of 18F-DCFPyL PET/CT in Detection of High-Risk Localized Prostate Cancer: Comparison With mpMRI

OBJECTIVE. The purpose of this study was to assess the utility of PET with (2S)-2-[[(1S)-1-carboxy-5-[(6-(¹⁸F)fluoranylpyridine-3-carbonyl)amino]pentyl]carbamoylamino]pentanedioic acid (¹⁸F-DCFPyL), a prostate-specific membrane antigen (PSMA)-targeted radiotracer, in the detection of high-risk localized prostate cancer as compared with multiparametric MRI (mpMRI). SUBJECTS AND METHODS. This HIPAA-compliant prospective study included 26 consecutive patients with localized high-risk prostate cancer (median age, 69.5 years [range, 53-81 years]; median prostate-specific antigen [PSA] level, 18.88 ng/mL [range, 1.03-20.00 ng/mL]) imaged with ¹⁸F-DCFPyL PET/CT and mpMRI. Images from PET/CT and mpMRI were evaluated separately, and suspicious areas underwent targeted biopsy. Lesion-based sensitivity and tumor detection rate were compared for PSMA PET and mpMRI. Standardized uptake value (SUV) and PSMA PET parameters were correlated with histopathology score, and uptake in tumor was compared with that in nonmalignant tissue. On a patient level, SUV and PSMA tumor volume were correlated with PSA density. RESULTS. Forty-four tumors (one in Gleason grade [GG] group 1, 12 in GG group 2, seven in GG group 3, nine in GG group 4, and 15 in GG group 5) were identified at histopathology. Sensitivity and tumor detection rate of ¹⁸F-DCFPyL PET/CT and mpMRI were similar (PET/CT, 90.9% and 80%; mpMRI, 86.4% and 88.4%; p = 0.58/0.17). Total lesion PSMA and PSMA tumor volume showed a relationship with GG (τ = 0.27 and p = 0.08, τ = 0.30 and p = 0.06, respectively). Maximum SUV in tumor was significantly higher than that in nonmalignant tissue (p < 0.05). Tumor burden density moderately correlated with PSA density (r = 0.47, p = 0.01). Five true-positive tumors identified on ¹⁸F-DCFPyL PET/CT were not identified on mpMRI. CONCLUSION. In patients with high-risk prostate cancer, ¹⁸F-DCFPyL PET/CT is highly sensitive in detecting intraprostatic tumors and can detect tumors missed on mpMRI. Measured uptake is significantly higher in tumor tissue, and PSMA-derived tumor burden is associated with severity of disease.

Evaluation of relationships between the final Gleason score, PI-RADS v2 score, ADC value, PSA level, and tumor diameter in patients that underwent radical prostatectomy due to prostate cancer

INTRODUCTION

This study aimed to investigate the relationship between the serum PSA level, Gleason score (GS), PI-RADS v2 score, tumor ADC_min value, and the largest tumor diameter in patients that underwent radical prostatectomy (RP) due to prostate cancer (PCa) and to comparatively evaluate the variables of these parameters in clinically significant and insignificant PCa groups.

MATERIALS AND METHODS

The mpMRI examinations of the patients who underwent RP due to PCa were retrospectively evaluated. According to the final GS, the lesions were divided into two groups as clinically significant (GS ≥ 7) and insignificant (GS ≤ 6). The PSA value, tumor ADC_min value, tumor diameter, and PI-RADS score were compared between the clinically significant and nonsignificant PCa groups using Student's t-test. The correlations between the serum PSA level, GS, PI-RADS v2 score, tumor ADC_min value, and tumor diameter were evaluated separately (Pearson's correlation analysis was used for peripheral gland tumors, and Spearman's correlation analysis for central gland tumors). A ROC analysis was undertaken to evaluate the efficacy of the tumor ADC_min, diameter and PSA values in differentiating clinically significant and nonsignificant tumors.

RESULTS

In both central and peripheral gland tumors, there was a correlation between the PSA level, tumor diameter, PI-RADS score, ADC_min value, and GS at various levels (poor, moderate, and high). In central gland tumors, there was no significant difference between the two groups in terms of the PSA value and PI-RADS scores (p > 0.05), but the ADC_min value and diameter of the tumor significantly differed (p < 0.05). For peripheral gland tumors, significant differences were observed in all parameters (p < 0.05). The cut-off values for the peripheral and central gland tumors are as follows: lesion diameter, 13.5 mm and 19 mm; tumor ADC_min, 0.709 × 10^-3 mm²/s and 0.874 × 10^-3 mm²/s; and PSA level, 8.47 ng/ml and 11.10 ng/ml, respectively.

CONCLUSION

The current PI-RADS v2 scoring system can be inadequate in distinguishing clinically significant and insignificant groups in central gland tumors. A separate cut-off value of the tumor diameter should be determined for central and peripheral gland tumors. Tumor ADC_min values can be used as a predictive parameter. The PSA cut-off value should be kept lower in peripheral gland tumors.

Comparing Prostate Imaging-Reporting and Data System Version 2 (PI-RADSv2) Category 1 and 2 Groups: Clinical Implication of Negative Multiparametric Magnetic Resonance Imaging

Objectives

To evaluate the clinicopathological differences between Prostate Imaging-Reporting and Data System (PI-RADS) version 2 (v2) category 1 and 2 groups. Materials and Methods. We retrospectively reviewed our two institutional clinical databases: (1) transrectal ultrasound (TRUS)/magnetic resonance imaging (MRI) fusion biopsy cohort (n = 706) and (2) radical prostatectomy (RP) cohort (n = 1403). Subsequently, we performed comparative analyses between PI-RADSv2 category 1 and 2 groups. Clinically significant prostate cancer (csPCa) was defined as the presence of Gleason score (GS) ≥ 3 + 4 in a single biopsy core, and adverse pathology (AP) was defined as high-grade (primary Gleason pattern 4 or any pattern 5) and/or non-organ-confined disease (pT3/N1). We also performed multivariate logistic regression analyses for AP.

Results

In the TRUS/MRI fusion biopsy cohort, no significant differences in detection rates of all cancer (18.2% vs. 29.0%, respectively, P = 0.730) or csPCa (9.1% vs. 9.9%, respectively, P = 0.692) were observed between PI-RADSv2 category 1 and 2 groups. There were no significant differences in pathologic outcomes including Gleason score (≥4 + 3, 21.2% vs. 29.9%, respectively, P = 0.420) or detection rate of AP (27.3% vs. 33.8%, respectively, P = 0.561) between the two groups in the RP cohort either. PI-RADSv2 category 1 or 2 had no significant association with AP, even in univariate analysis (P = 0.299).

Conclusions

PI-RADSv2 categories 1 and 2 had similar performance to predict clinicopathological outcomes. Consequently, these two categories may be unified into a single category. Negative mpMRI does not guarantee the absence of AP, as with csPCa.

Differences in negative predictive value of prostate MRI based in men with suspected or known cancer

Objective

To compare the negative predictive value (NPV) of multiparametric MRI for Gleason score (GS) ≥ 3+4 cancer and evaluate predictors of these tumors in men with suspected disease and under active surveillance (AS).

Materials and Methods

This retrospective study included 38 men with suspected prostate cancer and 38 under AS with scans assigned PI-RADS v2 scores 1 or 2 between May 2016 and September 2017. Biopsy results were no cancer, GS = 3+3, or GS ≥ 3+4. Pre-MRI PSA, gland volume, and PSA density were recorded. Chi-square, equality of proportions, and logistic regressions were used to analyze the data.

Results

Intermediate to high-grade cancer was found in 12.8% (95% CI = 2.3-23.3) and 35.9% (95% CI = 20.8-50.9) of men with suspected cancer, and under AS (p = 0.02), respectively. The NPV for GS ≥ 3+4 were 87.2% (suspected cancer; 76.7-97.7) and 64.1% (AS; 49.0-79.2). In neither group PSA significantly predicted cancer grade (p = 0.75 and 0.63). Although it did not reach conventional statistical significance, PSA density was a good predictor of cancer grade in men with suspected disease (p = 0.06), but not under AS (p = 0.62).

Conclusion

The NPV of multiparametric MRI for GS ≥ 3+4 is higher in men with suspected prostate cancer than in men under AS. PSA density ≤ 0.15 improved the prediction of intermediate to high-grade disease in patients without known cancer.

Predicting side-specific prostate cancer extracapsular extension: a simple decision rule of PSA, biopsy, and MRI parameters

Objective

To develop an easy-to-use side-specific tool for the prediction of prostate cancer extracapsular extension (ECE) using clinical, biopsy, and MRI parameters.

Materials and methods

Retrospective analysis of patients who underwent radical prostatectomy preceded by staging multiparametric MRI of the prostate was performed. Multivariate logistic regression analysis was used to choose independent predictors of ECE. Continuous variables were transformed to categorical ones by choosing threshold values using spline knots or testing thresholds used in previously described models. Internal validation of the rule was carried out as well as validation of other algorithms on our group was performed.

Results

In the analyzed period of time, 88 out of 164 patients who underwent radical prostatectomy met inclusion criteria. ECE was evidenced at radical prostatectomy in 41 patients (46.6%) and in 53 lobes (30.1%). In the multivariate analysis PSA, total percentage of cancerous tissue in cores (%PCa) and maximum tumour diameter (MTD) of Likert 3–5 lesions on MRI were independent predictors of ECE. The following rule for predicting side-specific ECE was proposed: %PCa ≥ 15% OR MTD ≥ 15 mm OR PSA ≥ 20 ng/mL. Internal validation of the algorithm revealed safe lower confidence limits for sensitivity and NPV, proving that model offers accurate risk grouping that can be safely used in decision-making.

Conclusion

The rule developed in this study makes ECE prediction fast, intuitive, and side-specific. However, until validated externally it should be used with caution.

Fusion prostate biopsy outperforms 12-core systematic prostate biopsy in patients with prior negative systematic biopsy: A multi-institutional analysis

INTRODUCTION AND OBJECTIVES

Patients with persistently elevated prostate specific antigen (PSA) and prior negative 12-core TRUS prostate biopsy (or biopsies) (systematic biopsy-SBx) are a diagnostic challenge. Repeat SBx or saturation biopsy in this cohort has been shown to have an even lower yield. The aim of our study is to compare the prostate cancer yield of magnetic resonance imaging (MRI) fusion biopsy (FBx) to SBx in a multi-institutional cohort comprised of patients with prior negative biopsies.

METHODS

A multi-institutional review was performed on patients with a history of one or more prior negative SBx who underwent multiparametric MRI (mpMRI), followed by FBx and SBx in the same session. Imaging protocol was standardized across institutions and institutional genitourinary radiologists and pathologists reviewed mpMRI and pathology, respectively. Gleason score (GS) distribution and risk classifications were recorded. Prostate cancer with GS ≥3 + 4 was defined as clinically significant (CS). Univariate and multivariable logistic regression was done to identify predictors of cancer detection on SBx and FBx.

RESULTS

Seven-hundred seventy-nine patients from four institutions were included in the study. Median age and prostate specific antigen (IQR) were 63.1 (58.5-68.0) years and 8.5 (5.9-13.1)ng/dl, respectively. Median number of prior negative biopsies (range) was 2.0 (1-16). The cancer detection rate (CDR) in the cohort was 346/779 patients (44.4%). Total CS CDR was 30.7% (239/779 patients), with FBx detecting 26.3% (205/779) of patients with CS disease and SBx diagnosing an additional 4.4% (34/779) of patients (P<0.001). Furthermore, of all cancers detected by each modality, FBx detected a higher proportion of CS cancer compared to SBx (one negative biopsy: 75 vs. 50%, P<0.001, 2-3 negative biopsy: 76 vs. 61%, P = 0.006, 4 or more negative biopsies: 84 vs. 52%, P = 0.006). As such, SBx added a relatively small diagnostic value to FBx for detecting CS disease (one negative biopsy 3.5%, 2-3 negative biopsies 5%, 4 or more negative biopsies: 1%). FBx also outperformed SBx for upgrading patients to an intermediate or high-risk cancer category (GS>6) (one negative biopsy 11.5% vs. 3.6%, 2-3 negative biopsy 10.3% vs. 5.3%, 4 or more negative biopsies 19.1% vs. 1.1%). On multivariable analysis, the number of prior negative biopsies was a significant negative predictor of CS CDR on SBx (P = 0.006), but not on FBx (P = 0.151).

CONCLUSIONS

Using a large multi-institutional cohort, we were able to demonstrate that FBx outperformed SBx in patients with prior negative systematic biopsy. This was due, in part, to the decreasing CS CDR by SBx with increased number of prior biopsies. The yield of FBx stayed constant and did not decrease with increased number of prior negative biopsies. Therefore, repeat SBx alone in patients with multiple prior negative biopsies will be hindered by lower yield and FBx should be utilized concurrently in these patients.