Extended and saturation prostatic biopsy in the diagnosis and characterisation of prostate cancer: a critical analysis of the literature

Synthesis and preclinical evaluation of 68Ga-labeled PSMA tracers with improved pharmacological properties

Prostate cancer (PCa) is one of the most common tumors in men, with the overexpression of prostate-specific membrane. In this study, we developed four new 68Ga-labeled PSMA-targeting tracers by introducing quinoline, phenylalanine and decanoic acid groups to enhance their lipophilicity, strategically limiting their metabolic pathway through the urinary system. Four radiotracers were synthesized with radiochemical purity >95 %, and exhibited high stability in vivo and in vitro. The inhibition constants (Ki) of SDTWS01-04 to PSMA were in the nanomolar range (<10 nM). Micro PET/CT imaging and biodistribution analysis revealed that 68Ga-SDTWS01 enabled clear tumor visualization in PET images at 1.5 h post-injection, with excellent pharmacokinetic properties. Notably, the kidney uptake of 68Ga-SDTWS01 significantly reduced, with higher tumor-to-kidney ratio (0.36 ± 0.02), tumor-to-muscle ratio (24.31 ± 2.10), compared with 68Ga-PSMA-11 (T/K: 0.15 ± 0.01; T/M: 14.97 ± 1.40), suggesting that 68Ga-SDTWS01 is a promising radiotracer for the diagnosis of PCa. Moreover, SDTWS01 with a chelator DOTA could also label 177Lu and 225Ac, which could be used for the treatment of PCa.

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.

Biomolecule-functionalized nanoformulations for prostate cancer theranostics

BACKGROUND

Even with the advancement in the areas of cancer nanotechnology, prostate cancer still poses a major threat to men's health. Nanomaterials and nanomaterial-derived theranostic systems have been explored for diagnosis, imaging, and therapy for different types of cancer still, for prostate cancer they have not delivered at full potential because of the limitations like in vivo biocompatibility, immune responses, precise targetability, and therapeutic outcome associated with the nanostructured system.

AIM OF REVIEW

Functionalizing nanomaterials with different biomolecules and bioactive agents provides advantages like specificity towards cancerous tumors, improved circulation time, and modulation of the immune response leading to early diagnosis and targeted delivery of cargo at the site of action.

KEY SCIENTIFIC CONCEPTS OF REVIEW

In this review, we have emphasized the classification and comparison of various nanomaterials based on biofunctionalization strategy and source of biomolecules such that it can be used for possible translation in clinical settings and future developments. This review highlighted the opportunities for embedding highly specific biological targeting moieties (antibody, aptamer, oligonucleotides, biopolymer, peptides, etc.) on nanoparticles which can improve the detection of prostate cancer-associated biomarkers at a very low limit of detection, direct visualization of prostate tumors and lastly for its therapy. Lastly, special emphasis was given to biomimetic nanomaterials which include functionalization with extracellular vesicles, exosomes and viral particles and their application for prostate cancer early detection and drug delivery. The present review paves a new pathway for next-generation biofunctionalized nanomaterials for prostate cancer theranostic application and their possibility in clinical translation.

'Stealth' Prostate Tumors

BACKGROUND

The aim of this study was to determine the false negative rates of prebiopsy magnetic resonance imaging (MRI) and MRI-ultrasound (US) 12-core systematic prostate biopsy (PBx) by analyzing radical prostatectomy specimens.

METHODS

This retrospective study included 3600 prostate cancer (PCa) patients who underwent robot-assisted laparoscopic radical prostatectomy. Based on comparison of lobe-specific data on final pathology with preoperative biopsy and imaging data, the study population was subdivided into group I-contralateral (CL) benign PBx (n = 983), group II-CL and/or bilateral (BL) non-suspicious mpMRI (n = 2223) and group III-CL benign PBx + non-suspicious mpMRI (n = 688). This population was studied for the presence of PCa, clinically significant PCa (csPCa), extracapsular extension (ECE) (pathological stage pT3), positive frozen section and final positive surgical margin (PSM) in the CL lobe. Descriptive statistics were performed.

RESULTS

In subgroups I, II and III, PCa was respectively detected in 21.5%, 37.7% and 19.5% of cases, and csPCa in 11.3%, 16.3% and 10.3% of cases. CL pT3 disease was seen in 4.5%, 4% and 5.5%, and CL surgical margins and/or frozen section analysis were positive in 6%, 7% and 5% of cases in subgroups I, II and III, respectively.

CONCLUSIONS

There are still significant rates of false negatives in the standard care diagnostics of PCa. Further strategies are required to improve the accuracy of diagnosis and determination of tumor location.

Ultrasound-based radiomics score for pre-biopsy prediction of prostate cancer to reduce unnecessary biopsies

BACKGROUND

Patients undergoing prostate biopsies (PBs) suffer from low positive rates and potential risk for complications. This study aimed to develop and validate an ultrasound (US)-based radiomics score for pre-biopsy prediction of prostate cancer (PCa) and subsequently reduce unnecessary PBs.

METHODS

Between December 2015 and March 2018, 196 patients undergoing initial transrectal ultrasound (TRUS)-guided PBs were retrospectively enrolled and randomly assigned to the training or validation cohort at a ratio of 7:3. A total of 1044 radiomics features were extracted from grayscale US images of each prostate nodule. After feature selection through the least absolute shrinkage and selection operator (LASSO) regression model, the radiomics score was developed from the training cohort. The prediction nomograms were developed using multivariate logistic regression analysis based on the radiomics score and clinical risk factors. The performance of the nomograms was assessed and compared in terms of discrimination, calibration, and clinical usefulness.

RESULTS

The radiomics score consisted of five selected features. Multivariate logistic regression analysis demonstrated that the radiomics score, age, total prostate-specific antigen (tPSA), and prostate volume were independent factors for prediction of PCa (all p < 0.05). The integrated nomogram incorporating the radiomics score and three clinical risk factors reached an area under the curve (AUC) of 0.835 (95% confidence interval [CI], 0.729-0.941), thereby outperforming the clinical nomogram which based on only clinical factors and yielded an AUC of 0.752 (95% CI, 0.618-0.886) (p = 0.04). Both nomograms showed good calibration. Decision curve analysis indicated that using the integrated nomogram would add more benefit than using the clinical nomogram.

CONCLUSION

The radiomics score was an independent factor for pre-biopsy prediction of PCa. Addition of the radiomics score to the clinical nomogram shows incremental prognostic value and may help clinicians make precise decisions to reduce unnecessary PBs.

Multiparametric ultrasound of prostate: role in prostate cancer diagnosis

Recent advances in ultrasonography (US) technology established modalities, such as Doppler-US, HistoScanning, contrast-enhanced ultrasonography (CEUS), elastography, and micro-ultrasound. The early results of these US modalities have been promising, although there are limitations including the need for specialized equipment, inconsistent results, lack of standardizations, and external validation. In this review, we identified studies evaluating multiparametric ultrasonography (mpUS), the combination of multiple US modalities, for prostate cancer (PCa) diagnosis. In the past 5 years, a growing number of studies have shown that use of mpUS resulted in high PCa and clinically significant prostate cancer (CSPCa) detection performance using radical prostatectomy histology as the reference standard. Recent studies have demonstrated the role mpUS in improving detection of CSPCa and guidance for prostate biopsy and therapy. Furthermore, some aspects including lower costs, real-time imaging, applicability for some patients who have contraindication for magnetic resonance imaging (MRI) and availability in the office setting are clear advantages of mpUS. Interobserver agreement of mpUS was overall low; however, this limitation can be improved using standardized and objective evaluation systems such as the machine learning model. Whether mpUS outperforms MRI is unclear. Multicenter randomized controlled trials directly comparing mpUS and multiparametric MRI are warranted.

Diagnostic accuracy and clinical implications of robotic assisted MRI-US fusion guided target saturation biopsy of the prostate

MRI-targeted prostate biopsy improves detection of clinically significant prostate cancer (PCa). However, up to 70% of PCa lesions display intralesional tumor heterogeneity. Current target sampling strategies do not yet adequately account for this finding. This prospective study included 118 patients who underwent transperineal robotic assisted biopsy of the prostate. We identified a total of 58 PCa-positive PI-RADS lesions. We compared diagnostic accuracy of a target-saturation biopsy strategy to accuracy of single, two, or three randomly selected targeted biopsy cores and analysed potential clinical implications. Intralesional detection of clinically significant cancer (ISUP ≥ 2) was 78.3% for target-saturation biopsy and 39.1%, 52.2%, and 67.4% for one, two, and three targeted cores, respectively. Target-saturation biopsies led to a more accurate characterization of PCa in terms of Gleason score and reduced rates of significant cancer missed. Compared to one, two, and three targeted biopsy cores, target-saturation biopsies led to intensified staging procedures in 21.7%, 10.9, and 8.7% of patients, and ultimately to a potential change in therapy in 39.1%, 26.1%, and 10.9% of patients. This work presents the concept of robotic-assisted target saturation biopsy. This technique has the potential to improve diagnostic accuracy and thus individual staging procedures and treatment decisions.

Rationale and protocol for randomized study of transrectal and transperineal prostate biopsy efficacy and complications (ProBE-PC study)

BACKGROUND

Rrisk of infection and hospitalization after transrectal prostate biopsy (TRBx) has been increasing worldwide. Several modified antibiotic regimens have met with variable success in preventing such infections. Transperineal prostate biopsy (TPBx) is increasingly recommended as the preferred alternative due to a potentially lower risk of post-biopsy infections. Aim of this review is to define the magnitude of post-biopsy complications and the effectiveness of preventive strategies, including TPBx approach.

METHODS

We performed a focused review of literature on infectious complications after TRBx and detailed the use of various preventive measures. We summarized the effectiveness of several preventive measures, including TPBx, and outlined the inconsistencies in reported outcomes. We identified potential barriers to the uptake of TPBx, including the gap in knowledge such as lack of high-quality evidence.

RESULTS

Several antibiotic prophylaxis protocols, including targeted and augmented, have been utilized for TRBx without demonstrating a clearly superior regimen. Of the non-antibiotic preventive measure, povidone-iodine rectal prep appears to be most effective strategy. Several single-arm cohort studies have reported very low rates of infections after TPBx and demonstrated the feasibility of an office-based procedure. However, barriers to the adoption of TPBx exist including retrospective data, and conflicting results showing minimal reduction in complications with increased burden of resource utilization. Presently, there are no randomized studies comparing the infectious complications after TRBx and TPBx. We discuss the rationale and protocol for a randomized controlled trial to determine the comparative effectiveness of biopsy techniques.

CONCLUSIONS

TPBx approach has the potential to lower the rate of post-biopsy infections and hospitalizations. However, there are several barriers to widespread adoption of this approach including inconsistencies in reported outcomes and lack of Level-1 evidence. Randomized controlled studies are required to directly compare the infectious complications associated with each biopsy procedure.

Effect of training and individual operator's expertise on prostate cancer detection through prostate biopsy: Implications for the current quantitative training evaluation system

Purpose

This study was conducted to evaluate the relevance of training and experience to gaining expertise in prostate biopsy based on an assessment of outcomes from the performance of urology residents.

Materials and Methods

We retrospectively reviewed the medical records of 10,299 patients who underwent prostate biopsy by 50 operators under a unified urology residency program. The number of prostate biopsies performed by an operator for each patient was used as an indicator of operator experience. Residents were grouped into quartiles according to cancer detection rates in the first 50 and the last 50 procedures.

Results

Among 10,299 patients (median age, 67.5 years; median prostate-specific antigen [PSA], 7.04 ng/mL), the overall prostate cancer detection rate and that for patients with PSA <10.0 ng/mL were 37.0% and 25.9%, respectively. Operator experience was a significant predictor for cancer detection in patients with PSA <10.0 ng/mL. Cancer detection rates and the proportion of more advanced prostate cancers were higher in the last 50 cases than in the first 50 cases. Detection rates varied significantly among operator; residents with higher detection rates at training initiation showed even higher detection rates after additional training.

Conclusions

Training that adds to the cumulative experience of a trainee appears to play a meaningful role in improving cancer detection rates. The level of skill required to achieve mastery for independent practice may be assessed from the accuracy results of prostate biopsy procedures, and trainees with poor rates will require more technical training to improve precision.

Can Prostate-Specific Antigen Density Be an Index to Distinguish Patients Who Can Omit Repeat Prostate Biopsy in Patients with Negative Magnetic Resonance Imaging?

Purpose

We evaluated the negative predictive value (NPV) of multiparametric magnetic resonance imaging (mpMRI) in detecting clinically significant prostate cancer (csPCa) according to biopsy setting and prostate-specific antigen density (PSAD) using transperineal template-guided saturation prostate biopsy (TPB) as the reference standard.

Methods

A total of 161 patients with biopsy histories and negative pre-biopsy mpMRI (Prostate Imaging Reporting and Data System version 2 scores of less than 3) participated in the study. TPB was performed on the following indications: “prior negative biopsy” in patients with persistent suspicion of prostate cancer (n = 91) or “confirmatory biopsy” in patients who were candidates for active surveillance (n = 70). The csPCa was defined as a Gleason score of 3 + 4 or greater. We calculated the NPV of mpMRI in detecting csPCa according to biopsy history and prostate-specific antigen density (PSAD) and conducted a logistic regression analysis to determine the clinical predicator for the absence of csPCa.

Results

The detection rate of csPCa was 5.5% in the prior negative biopsy group and 14.3% in the confirmatory biopsy group (P = 0.057). None of the variables in the logistic regression models including PSAD <0.15 ng/mL/cc and prior negative biopsy could predict the absence of csPCa. The NPV of mpMRI in detecting csPCa in patients with a prior negative biopsy worsen from 94.5% to 93.3% when combined with PSAD <0.15 ng/mL/cc.

Conclusion

Patients with negative mpMRI findings may not omit repeat biopsy even if their prior biopsy histories are negative and PSADs are <0.15 ng/mL/cc.

Advances in the selection of patients with prostate cancer for active surveillance

Early identification and management of prostate cancer completely changed with the discovery of prostate-specific antigen. However, improved detection has also led to overdiagnosis and consequently overtreatment of patients with low-risk disease. Strategies for the management of patients using active surveillance - the monitoring of clinically insignificant disease until intervention is warranted - were developed in response to this issue. The success of this approach is critically dependent on the accurate selection of patients who are predicted to be at the lowest risk of prostate cancer mortality. The Epstein criteria for clinically insignificant prostate cancer were first published in 1994 and have been repeatedly validated for risk-stratification and selection for active surveillance over the past few decades. Current active surveillance programmes use modified criteria with 30-50% of patients receiving treatment at 10 years. Nonetheless, tools for prostate cancer diagnosis have continued to evolve with improvements in biopsy format and targeting, advances in imaging technologies such as multiparametric MRI, and the identification of serum-, tissue- and urine-based biomarkers. These advances have the potential to further improve the identification of men with low-risk disease who can be appropriately managed using active surveillance.

Prostate Cancer Biomarker Development: National Cancer Institute's Early Detection Research Network Prostate Cancer Collaborative Group Review

Prostate cancer remains the most common non-skin cancer and second leading cause of death among men in the United States. Although progress has been made in diagnosis and risk assessment, many clinical questions remain regarding early identification of prostate cancer and management. The early detection of aggressive disease continues to provide high curative rates if diagnosed in a localized state. Unfortunately, prostate cancer displays significant heterogeneity within the prostate organ and between individual patients making detection and treatment strategies complex. Although prostate cancer is common among men, the majority will not die from prostate cancer, introducing the issue of overtreatment as a major concern in clinical management of the disease. The focus of the future is to identify those at highest risk for aggressive prostate cancer and to develop prevention and screening strategies, as well as discerning the difference in malignant potential of diagnosed tumors. The Prostate Cancer Research Group of the National Cancer Institute's Early Detection Research Network has contributed to the progress in addressing these concerns. This summary is an overview of the activities of the group.See all articles in this CEBP Focus section, "NCI Early Detection Research Network: Making Cancer Detection Possible."

MRI-targeted or systematic random biopsies for prostate cancer diagnosis in biopsy naïve patients: follow-up of a PRECISION trial-like retrospective cohort

BACKGROUND

To test clinically significant prostate cancer (csPCa) rates during follow-up in biopsy naïve patients that underwent two different diagnostic pathways: (1) SB GROUP (n = 354): systematic random biopsies (SB) vs. (2) TB GROUP (n = 264): multiparametric magnetic resonance imaging (mpMRI) and only targeted biopsies (TB) of PI-RADS ≥ 3 lesions. Patients with PI-RADS ≤ 2 score avoided prostate biopsies.

METHODS

Retrospective single centre study of 618 biopsy naive patients (2015-2018). Two different definitions of csPCa were used: (1) csPCa ISUP GG ≥ 2 (ISUP grade group [GG] ≥ 2) and (2) csPCa ISUP GG ≥ 3. Kaplan-Meier plots and univariable Cox regression models tested rates over time of csPCa ISUP GG ≥ 2 and caPCa ISUP GG ≥ 3 in SB GROUP vs. TB GROUP.

RESULTS

At initial biopsy, TB achieved higher rates of csPCa ISUP GG ≥ 2 (35.3 vs. 18.9%; p < 0.001) and csPCa ISUP GG ≥ 3 (12.6 vs. 6.2%; p = 0.04), relative to SB. After a median time follow-up of 36 months, the rates of csPCa ISUP GG ≥ 2 (6.1 vs. 4.4%; p = 0.6) and csPCa ISUP GG ≥ 3 (3.3 vs. 1.1%; p = 0.2) were similar in SB GROUP vs. TB GROUP. Moreover, in TB GROUP patients that avoided prostate biopsies because of negative baseline mpMRI (n = 145), only 4.1% exhibited csPCa ISUP GG ≥ 2 during follow-up. Moreover, none of these patients (PI-RADS ≤ 2) had csPCa ISUP GG ≥ 3.

CONCLUSIONS

In biopsy naïve setting, a diagnostic pathway including pre-biopsy mpMRI and TB of only PCa suspicious lesions is not associated with higher rates of csPCa during follow-up, relative to a diagnostic pathway of SB. Moreover, patients with negative baseline mpMRI could safely avoid prostate biopsies and could be followed with repeated PSA testing, since only a small proportion of them would harbor csPCa.

Functionalized NIR-II Semiconducting Polymer Nanoparticles for Single-cell to Whole-Organ Imaging of PSMA-Positive Prostate Cancer

Development of molecular probes holds great promise for early diagnosis of aggressive prostate cancer. Here, 2-[3-(1,3-dicarboxypropyl) ureido] pentanedioic acid (DUPA)-conjugated ligand and bis-isoindigo-based polymer (BTII) are synthesized to formulate semiconducting polymer nanoparticles (BTII-DUPA SPN) as a prostate-specific membrane antigen (PSMA)-targeted probe for prostate cancer imaging in the NIR-II window. Insights into the interaction of the imaging probes with the biological targets from single cell to whole organ are obtained by transient absorption (TA) microscopy and photoacoustic (PA) tomography. At single-cell level, TA microscopy reveals the targeting efficiency, kinetics, and specificity of BTII-DUPA SPN to PSMA-positive prostate cancer. At organ level, PA tomographic imaging of BTII-DUPA SPN in the NIR-II window demonstrates superior imaging depth and contrast. By intravenous administration, BTII-DUPA SPN demonstrates selective accumulation and retention in the PSMA-positive tumor, allowing noninvasive PA detection of PSMA overexpressing prostate tumors in vivo. The distribution of nanoparticles inside the tumor tissue is further analyzed through TA microscopy. These results collectively demonstrate BTII-DUPA SPN as a promising probe for prostate cancer diagnosis by PA tomography.

Comparison of Tumor Volume Parameters on Prostate Cancer Biopsies

CONTEXT.—

Prostate biopsy reports require an indication of prostate cancer volume. No consensus exists on the methodology of tumor volume reporting.

OBJECTIVE.—

To compare the prognostic value of different biopsy prostate cancer volume parameters.

DESIGN.—

Prostate biopsies of the European Randomized Study of Screening for Prostate Cancer were reviewed (n = 1031). Tumor volume was quantified in 6 ways: average estimated tumor percentage, measured total tumor length, average calculated tumor percentage, greatest tumor length, greatest tumor percentage, and average tumor percentage of all biopsies. Their prognostic value was determined by using either logistic regression for extraprostatic expansion (EPE) and surgical margin status after radical prostatectomy (RP), or Cox regression for biochemical recurrence-free survival (BCRFS) and disease-specific survival (DSS) after RP (n = 406) and radiation therapy (RT) (n = 508).

RESULTS.—

All tumor volume parameters were significantly mutually correlated (R2 > 0.500, P < .001). None were predictive for EPE, surgical margin, or BCRFS after RP in multivariable analysis, including age, prostate-specific antigen, number of positive biopsies, and grade group. In contrast, all tumor volume parameters were significant predictors for BCRFS (all P < .05) and DSS (all P < .05) after RT, except greatest tumor length. In multivariable analysis including only all tumor volume parameters as covariates, calculated tumor length was the only predictor for EPE after RP (P = .02) and DSS after RT (P = .02).

CONCLUSIONS.—

All tumor volume parameters had comparable prognostic value and could be used in clinical practice. If tumor volume quantification is a threshold for treatment decision, calculated tumor length seems preferential, slightly outperforming the other parameters.

Is targeted biopsy really needed when performing systematic prostate biopsy to raise the detection rate for prostate cancer in patients with prostate-specific antigen ≤10 ng/mL?

Targeted biopsy with multiparametric magnetic resonance imaging and hypoechoic lesions on transrectal ultrasound has been implemented to increase prostate cancer detection rate.We compared the detection abilities of systematic prostate biopsy, hypoechoic lesion-targeted biopsy (HL-TBx), and cognitive magnetic resonance imaging-targeted biopsy (MRI-TBx) in patients with suspected prostate cancer. Between September 2014 and August 2016, 193 patients with a prostate-specific antigen level of 3 to 10 ng/mL underwent HL-TBx or MRI-TBx. In patients who refused magnetic resonance imaging examination before prostate biopsy, HL-TBx was performed. We compared cancer detection rates and pathologic outcomes between systematic prostate biopsy and HL-TBx or MRI-TBx.The cancer detection rates for HL-TBx and MRI-TBx were 40.8% and 43.8%, respectively, without a significant difference (P = .683). Of the 81 patients diagnosed with prostate cancer, most patients (77 patients, 95.1%) were diagnosed with prostate cancer by systematic prostate biopsy. The detection ability for prostate cancer was significantly better for systematic prostate biopsy than for HL-TBx or MRI-TBx (P < .001).The detection abilities for clinically significant prostate cancer similar between HL-TBx and systematic prostate biopsy. Systematic prostate biopsy alone should be recommended for detection prostate cancer in patients with a prostate-specific antigen ≤10 ng/mL.

Prostate Biopsy Processing

OBJECTIVES

Current protocols for processing multiple prostate biopsy cores per case are uneconomical and cumbersome. Tissue fragmentation and loss compromise cancer diagnosis. We sought to study an alternate method to improve processing and diagnosis of prostate cancer.

METHODS

Two sets of sextant biopsy specimens from near-identical locations were obtained ex vivo from 48 prostate specimens. One set was processed in the standard fashion while the other was processed using the BxChip, a proprietary biomimetic matrix that accommodates six cores on a single chip. Parameters including grossing, embedding, sectioning and reading time, length of tissue, and degree of fragmentation were compared.

RESULTS

A significant reduction (more than threefold) in preanalytical and analytical time was observed using the multiplex method. Nonlinear fragmentation was absent, in contrast to standard processing.

CONCLUSIONS

The BxChip reduced tissue fragmentation and increased efficiency of prostate biopsy diagnosis. It also resulted in overall cost savings and significantly increased tissue length.

[Prostate pathology recommendations from the Uropathology working group of the Spanish Society of Pathology]

These guidelines from the uropathology working group of the Spanish Society of Pathology (SEAP) are based on the European and ISUP 2015 recommendations and those of the College of American Pathologists, as well as the latest WHO 2016, TNM (AJCC) 2017 classifications. They include recommendations for specimen sampling, macro- and microscopic examination and immunohistochemistry. Gleason patterns are specified: Gleason pattern 3 includes hyperplastic, atrophic and microcystic glands, while pattern 4 includes all cribriform or glomeruloid glands. The Gleason score in prostatectomy specimens may change; if a tertiary pattern occurs in more than 5% of the tumour, it becomes a secondary pattern. In both biopsies and prostatectomy specimens, if the Gleason score is 7, the percentage of pattern 4 should be stated. Gleason scoring in tumor variants and special situations should also be specified. These recommendations should be adapted according to the resources available.

Cumulative Cancer Locations is a Novel Metric for Predicting Active Surveillance Outcomes: A Multicenter Study

BACKGROUND

Active surveillance (AS) of prostate cancer (PC) has increased in popularity to address overtreatment.

OBJECTIVE

To determine whether a novel metric, cumulative cancer locations (CCLO), can predict AS outcomes in a group of AS patients with low and very low risk.

DESIGN, SETTING, AND PARTICIPANTS

CCLO is obtained by summing the total number of histological cancer-positive locations in both diagnostic and confirmatory biopsies (Bx). The retrospective study cohort comprised three prospective AS cohorts (Helsinki University Hospital: n=316; European Institute of Oncology: n=204; and University of Münster: n=89).

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

We analyzed whether risk stratification based on CCLO predicts different AS outcomes: protocol-based discontinuation (PBD), Gleason upgrading (GU) during AS, and adverse findings in radical prostatectomy (RP) specimens.

RESULTS

In Kaplan Meier analyses, patients in the CCLO high-risk group experienced significantly shorter event-free survival for all outcomes (PBD, GU, and adverse RP findings; all p<0.002). In multivariable Cox regression analysis, patients in the CCLO high-risk group had a significantly higher risk of experiencing PBD (hazard ratio [HR] 12.15, 95% confidence interval [CI] 6.18-23.9; p<0.001), GU (HR 6.01, 95% CI 2.16-16.8; p=0.002), and adverse RP findings (HR 9.144, 95% CI 2.27-36.9; p=0.006). In receiver operating characteristic analyses, the area under the curve for CCLO outperformed the number of cancer-positive Bxs in confirmatory Bx in predicting PBD (0.734 vs 0.682), GU (0.655 vs 0.576) and adverse RP findings (0.662 vs 0.561) and the added value was supported by decision curve analysis.

CONCLUSIONS

CCLO is distinct from the number of positive Bx cores. Higher CCLO predicts AS outcomes and may aid in selection of patients for AS.

PATIENT SUMMARY

For patients on active surveillance for prostate cancer, the cumulative number of cancer-positive locations in diagnostic and confirmatory biopsies is a predictor of active surveillance outcomes.

Multiparametric MRI to improve detection of prostate cancer compared with transrectal ultrasound-guided prostate biopsy alone: the PROMIS study

BACKGROUND

Men with suspected prostate cancer usually undergo transrectal ultrasound (TRUS)-guided prostate biopsy. TRUS-guided biopsy can cause side effects and has relatively poor diagnostic accuracy. Multiparametric magnetic resonance imaging (mpMRI) used as a triage test might allow men to avoid unnecessary TRUS-guided biopsy and improve diagnostic accuracy.

OBJECTIVES

To (1) assess the ability of mpMRI to identify men who can safely avoid unnecessary biopsy, (2) assess the ability of the mpMRI-based pathway to improve the rate of detection of clinically significant (CS) cancer compared with TRUS-guided biopsy and (3) estimate the cost-effectiveness of a mpMRI-based diagnostic pathway.

DESIGN

A validating paired-cohort study and an economic evaluation using a decision-analytic model.

SETTING

Eleven NHS hospitals in England.

PARTICIPANTS

Men at risk of prostate cancer undergoing a first prostate biopsy.

INTERVENTIONS

Participants underwent three tests: (1) mpMRI (the index test), (2) TRUS-guided biopsy (the current standard) and (3) template prostate mapping (TPM) biopsy (the reference test).

MAIN OUTCOME MEASURES

Diagnostic accuracy of mpMRI, TRUS-guided biopsy and TPM-biopsy measured by sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) using primary and secondary definitions of CS cancer. The percentage of negative magnetic resonance imaging (MRI) scans was used to identify men who might be able to avoid biopsy.

RESULTS

Diagnostic study - a total of 740 men were registered and 576 underwent all three tests. According to TPM-biopsy, the prevalence of any cancer was 71% [95% confidence interval (CI) 67% to 75%]. The prevalence of CS cancer according to the primary definition (a Gleason score of ≥ 4 + 3 and/or cancer core length of ≥ 6 mm) was 40% (95% CI 36% to 44%). For CS cancer, TRUS-guided biopsy showed a sensitivity of 48% (95% CI 42% to 55%), specificity of 96% (95% CI 94% to 98%), PPV of 90% (95% CI 83% to 94%) and NPV of 74% (95% CI 69% to 78%). The sensitivity of mpMRI was 93% (95% CI 88% to 96%), specificity was 41% (95% CI 36% to 46%), PPV was 51% (95% CI 46% to 56%) and NPV was 89% (95% CI 83% to 94%). A negative mpMRI scan was recorded for 158 men (27%). Of these, 17 were found to have CS cancer on TPM-biopsy. Economic evaluation - the most cost-effective strategy involved testing all men with mpMRI, followed by MRI-guided TRUS-guided biopsy in those patients with suspected CS cancer, followed by rebiopsy if CS cancer was not detected. This strategy is cost-effective at the TRUS-guided biopsy definition 2 (any Gleason pattern of ≥ 4 and/or cancer core length of ≥ 4 mm), mpMRI definition 2 (lesion volume of ≥ 0.2 ml and/or Gleason score of ≥ 3 + 4) and cut-off point 2 (likely to be benign) and detects 95% (95% CI 92% to 98%) of CS cancers. The main drivers of cost-effectiveness were the unit costs of tests, the improvement in sensitivity of MRI-guided TRUS-guided biopsy compared with blind TRUS-guided biopsy and the longer-term costs and outcomes of men with cancer.

LIMITATIONS

The PROstate Magnetic resonance Imaging Study (PROMIS) was carried out in a selected group and excluded men with a prostate volume of > 100 ml, who are less likely to have cancer. The limitations in the economic modelling arise from the limited evidence on the long-term outcomes of men with prostate cancer and on the sensitivity of MRI-targeted repeat biopsy.

CONCLUSIONS

Incorporating mpMRI into the diagnostic pathway as an initial test prior to prostate biopsy may (1) reduce the proportion of men having unnecessary biopsies, (2) improve the detection of CS prostate cancer and (3) increase the cost-effectiveness of the prostate cancer diagnostic and therapeutic pathway. The PROMIS data set will be used for future research; this is likely to include modelling prognostic factors for CS cancer, optimising MRI scan sequencing and biomarker or translational research analyses using the blood and urine samples collected. Better-quality evidence on long-term outcomes in prostate cancer under the various management strategies is required to better assess cost-effectiveness. The value-of-information analysis should be developed further to assess new research to commission.

TRIAL REGISTRATION

Current Controlled Trials ISRCTN16082556 and NCT01292291.

FUNDING

This project was funded by the National Institute for Health Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 22, No. 39. See the NIHR Journals Library website for further project information. This project was also supported and partially funded by the NIHR Biomedical Research Centre at University College London (UCL) Hospitals NHS Foundation Trust and UCL and by The Royal Marsden NHS Foundation Trust and The Institute of Cancer Research Biomedical Research Centre and was co-ordinated by the Medical Research Council's Clinical Trials Unit at UCL (grant code MC_UU_12023/28). It was sponsored by UCL. Funding for the additional collection of blood and urine samples for translational research was provided by Prostate Cancer UK.

Characterization of clinical human prostate cancer lesions using 3.0-T sodium MRI registered to Gleason-graded whole-mount histopathology

BACKGROUND

Overtreatment of prostate cancer (PCa) is a healthcare issue. Development of noninvasive imaging tools for improved characterization of prostate lesions might reduce overtreatment.

PURPOSE

To measure the distribution of tissue sodium concentration (TSC), proton T₂ -weighted signal, and apparent diffusion coefficient (ADC) values in human PCa and to test the presence of a correlation between regional differences in imaging metrics and the Gleason grade of lesions determined from histopathology.

STUDY TYPE

Cross-sectional.

SUBJECTS

Ten men with biopsy-proven PCa.

SEQUENCES/FIELD STRENGTH

Sodium, proton T₂ -weighted, and diffusion-weighted MRI data were acquired using Broad-Band 3D-Fast-Gradient-Recalled, 3D Cube (Isotropic 3D-Fast-Turbo-Spin-Echo acquisition) and 2D Spin-Echo sequences, respectively, with a 3.0T MR scanner.

ASSESSMENT

All imaging data were coregistered to Gleason-graded postprostatectomy histology, as the standard for prostate cancer lesion characterization. Regional TSC and T₂ data were assessed using percent changes from healthy tissue of the same patient (denoted ΔTSC, ΔT₂ ).

STATISTICS

Differences in ΔTSC, ADC, and ΔT₂ as a function of Gleason score were analyzed for each imaging contrast using a one-way analysis of variance or a nonparametric t-test. Correlations between imaging data measures and Gleason score were assessed using a Spearman's ranked correlation.

RESULTS

Evaluation of the correlation of ΔTSC, ADC, and ΔT₂ datasets with Gleason scoring revealed that only the correlation between ΔTSC and Gleason score was statistically significant (r_s  = 0.791, p < 0.01), whereas the correlations of ADC and ΔT₂ with Gleason score were not (r_s  = -0.306, p = 0.079 and r _s  = -0.069, p = 0.699, respectively). In addition, all individual patients showed monotonically increasing ΔTSC with Gleason score.

DATA CONCLUSION

The results of this preliminary study suggest that changes in TSC, assessed by sodium MRI, has utility as a noninvasive imaging assay to accurately characterize PCa lesions. Sodium MRI may provide useful complementary information on mpMRI, which may assist the decision-making of men choosing either active surveillance or treatment.

LEVEL OF EVIDENCE

1 Technical Efficacy: Stage 2 J. Magn. Reson. Imaging 2019;49:1409-1419.

The Heterogeneity of Prostate Cancer: A Practical Approach

Prostate cancer is a paradigm tumor model for heterogeneity in almost every sense. Its clinical, spatial, and morphological heterogeneity divided by the high-level molecular genetic diversity outline the complexity of this disease in the clinical and research settings. In this review, we summarize the main aspects of prostate cancer heterogeneity at different levels, with special attention given to the spatial heterogeneity within the prostate, and to the standard morphological heterogeneity, with respect to tumor grading and modern classifications. We also cover the complex issue of molecular genetic heterogeneity, discussing it in the context of the current evidence of the genetic characterization of prostate carcinoma; the interpatient, intertumoral (multifocal disease), and intratumoral heterogeneity; tumor clonality; and metastatic disease. Clinical and research implications are summarized and serve to address the most pertinent problems stemming from the extreme heterogeneity of prostate cancer.

[Prostate cancer diagnostic by saturation randomized biopsy versus rigid targeted biopsy]

INTRODUCTION

Optimal diagram teaming up randomized biopsy (BR) to targeted biopsy (BC) is still missing for the diagnostic of prostate cancer (CP). This study compares diagram of 6, 12 or 18 BR with or without BC rigid.

METHODS

Between January 2014 and May 2016, 120 patients had prostate biopsy BR and BC. Each patient had 18 BR and BC. Results compared sextant (6 BR), standard (12 BR) and saturation (18 BR) protocol with or without the adding of BC for the detection of CP.

RESULTS

Rectal examination was normal, mean PSA at 8.99ng/mL and mean volume at 54cm³. It was first round for 48% of patients. Forty-four cancers were found by the group 18 BR+BC (control). The detection rate was respectively, for 6, 12 and 18 BR of 61%, 82% and 91%. The add of BC increased this detection of +27% for 6 BR+BC, +13% for 12 BR+BC and +9% for 18 BR+BC. BC found 70% of all CP. Nine percent of CP were missed by BR only. Significant CP (Gleason≥7) diagnostic was the same for 12 BR+BC and 18 BR+BC.

CONCLUSION

The add of BC to BR increase the detection of CP by 10%. Twelve BR+BC is the optimal diagram for the diagnostic of CP finding 95% of CP and 97% of significant CP.

LEVEL OF EVIDENCE

4.

The Influence of Serum Prostate-Specific Antigen on the Accuracy of Magnetic Resonance Imaging Targeted Biopsy versus Saturation Biopsy in Patients with Previous Negative Biopsy

Objective

We compared the prostate cancer (PCa) detection rates of targeted biopsy (TB) and saturation biopsy (SB) in patients with previous negative biopsy and the accuracy of TB and SB stratified by different serum prostate-specific antigen (PSA) levels.

Materials and Methods

Overall 185 patients were enrolled. In the magnetic resonance imaging (MRI) group, 65 men underwent TB and SB. In the control group, 120 men underwent SB alone. The primary outcome was the difference in PCa detection rate between the MRI group and control group. The secondary outcome was the difference in accuracy between TB and SB in detecting clinically significant PCa by stratifying the patients in the MRI group into those with PSA < 10 ng/ml and PSA ≥ 10 ng/ml.

Results

The detection rates for overall and clinically significant PCa were higher in the MRI group than in the control group (46.2% versus 20.9% and 43.1% versus 16.7%, both p < 0.001). In the MRI group, the accuracy of TB was higher than SB (94.7% versus 84.2%, p = 0.001) for the patients with PSA ≥ 10 ng/mL.

Conclusions

Combining TB and SB achieved the best cancer detection rate. The accuracy of TB was better than SB in the patients with serum PSA ≥ 10 ng/mL.

[Indications and limits of ablative therapies in prostate cancer]

OBJECTIVE

To perform a state of the art about indications and limits of ablative therapies for localized prostate cancer.

METHODS

A review of the scientific literature was performed in Medline database (http://www.ncbi.nlm.nih.gov) and Embase (http://www.embase.com) using different associations of keywords. Publications obtained were selected based on methodology, language and relevance. After selection, 107 articles were analysed.

RESULTS

The objective to combine reduction of side effects and oncological control has induced recent development of several ablative therapies. Beyond this heterogeneity, some preferential indications appear: unilateral cancer of low risk (but with significant volume, excluding active surveillance) or intermediate risk (excluding majority of grade 4); treatment targeted the index lesion, by quarter or hemi-ablation, based on biopsy and mpMRI. In addition, indications must considered specific limits of each energy, such as gland volume and tumor localization.

CONCLUSION

Based on new imaging and biopsy, ablative therapies will probably increased its role in the future in management of localize prostate cancer. The multiple ongoing trials will certainly be helpful to better define their indications and limits.

Transrectal ultrasound-guided biopsy for prostate cancer detection: Systematic and/or magnetic-resonance imaging-targeted

INTRODUCTION

Magnetic resonance imaging (MRI) is being more widely used in the detection of prostate cancer (PCa), particularly after an initial negative biopsy. In this study, we compared 12-core systematic biopsy (SYS), MRI-targeted biopsy (TAR), and the association of systematic and MRI-targeted (SYS+TAR) prostate biopsy in patients with previous biopsy and those who were biopsy-naive to evaluate the differences in terms of cancer detection and clinically significant cancer detection between the three modalities.

METHODS

Overall, 203 consecutive patients with suspicion of PCa were analyzed; 48.2% were biopsy-naive and 51.7% had at least one previous negative prostate biopsy. The median age was 66 years, median prostate-specific antigen (PSA) level was 7.9 ng/mL and median prostate volume was 46 mL. 38.9% had SYS, 19.2% TAR only, and 41.8% had SYS+TAR biopsy.

RESULTS

Overall, the PCa detection (PCaDR) was 63%. The SYS+TAR biopsy detected significantly more cancer than SYS and TAR only biopsies (72.9% vs. 56.9% and 53.8% respectively; p=0.03). Detection rate of clinically significant cancer (csPCaDR) was 50.7% overall; 65.8% in the SYS+TAR biopsy vs. 39.2% in the SYS and 48.7% in the TAR groups (p=0.002). In the biopsy-naive group, PCaDR and csPCaDR were significantly higher in the SYS+TAR group than in the SYS and TAR groups (p=0.01). In the repeat biopsy group, PCaDR and csPCaDR were equivalent in the TAR and SYS+TAR groups and higher than in the SYS group (p=0.001).

CONCLUSIONS

TAR biopsy, when added to SYS biopsy, was associated with a higher detection rate of csPCa in biopsy-naive patients when compared to TAR and SYS only biopsies. In patients after previous negative biopsy, detection rates of csPCa were equivalent for SYS+TAR and TAR only biopsies, but higher than SYS.

Immunohistochemical Validation of PSMA Expression Measured by 68Ga-PSMA PET/CT in Primary Prostate Cancer

⁶⁸Ga-labeled prostate-specific membrane antigen (⁶⁸Ga-PSMA) PET/CT has a proven role in staging and restaging of prostate cancer (PCA). The aims of this study were to evaluate the association of intraprostatic ⁶⁸Ga-PSMA PET/CT findings and PSMA expression in immunohistochemical staining and generate a cutoff value for differentiation between normal prostate (PN) and PCA. Methods: The data of 31 patients (mean age, 67.2 y) who underwent prostatectomy and preoperative PET were retrospectively analyzed. On PET, focally increased uptake in the prostate was suggestive of tumor. A region of interest was placed on the suggestive area to generate an SUV_max; a similar region of interest was placed on adjacent visually PN. Both PCA and PN were stained with monoclonal anti-PSMA antibody (clone 3E6, 1:100, M3620). Results: All intraprostatic PCA lesions on PET could be confirmed histopathologically. In PN sections (n = 31), median staining intensity was mild, median percentage of stained cells was 20% ± 14.24%, and median immunoreactive score (IRS) was 1. In PCA sections (n = 31), median IRS was 3, median staining intensity was strong, and median percentage of stained cells was 80% ± 16.46%. The mean SUV_max (±SD) of PCA (14.06 ± 15.56) was significantly higher than that of PN (2.43 ± 0.63; P < 0.001). Receiver-operating-characteristic curve analyses of the SUV_max of PCA, validated by immunohistochemical staining in 62 tissue samples, showed the best cutoff to be 3.15 (sensitivity, 97%; specificity, 90%; area under curve, 0.987). Applied to multifocal PCA, it resulted in sensitivity and specificity of 87% and 97% respectively. The mean SUV_max of PCA and PN for an IRS of less than 2 (n = 26; 2.52 ± 0.64) was significantly lower than the mean SUV_max for an IRS of 2 or more (n = 36; 12.38 ± 15.02; P < 0.001). The mean SUV_max was significantly lower in PCA samples with fewer than 50% stained cells (n = 30; 2.81 ± 2.35) than in samples with 50% or more (n = 32; 13.34 ± 15.55; P < 0.001). There was no correlation between the SUV_max of PCA and Gleason score (P = 0.54). Conclusion: This study showed that SUV_max on ⁶⁸Ga-PSMA PET/CT correlates significantly with PSMA expression in primary PCA, enabling the detection of PCA with a high sensitivity and specificity.

Transrectal real-time tissue elastography targeted biopsy coupled with peak strain index improves the detection of clinically important prostate cancer

The focus of the present study was to evaluate transrectal real-time tissue elastography (RTE)-targeted two-core biopsy coupled with peak strain index for the detection of prostate cancer (PCa) and to compare this method with 10-core systematic biopsy. A total of 141 patients were enrolled for evaluation. The diagnostic value of peak strain index was assessed using a receiver operating characteristic curve. The cancer detection rates of the two approaches and corresponding positive cores and Gleason score were compared. The cancer detection rate per core in the RTE-targeted biopsy (44%) was higher compared with that in systematic biopsy (30%). The peak strain index value of PCa was higher compared with that of the benign lesion. PCa was detected with the highest sensitivity (87.5%) and specificity (85.5%) using the threshold value of a peak strain index of ≥5.97 with an area under the curve value of 0.95. When the Gleason score was ≥7, RTE-targeted biopsy coupled with peak strain index detected 95.6% of PCa cases, but 84.4% were detected using systematic biopsy. Peak strain index as a quantitative parameter may improve the differentiation of PCa from benign lesions in the prostate peripheral zone. Transrectal RTE-targeted biopsy coupled with peak strain index may enhance the detection of clinically significant PCa, particularly when combined with systematic biopsy.

Multi-parametric MRI imaging of the prostate-implications for focal therapy

The primary goal of a focal therapy treatment paradigm is to achieve cancer control through targeted tissue destruction while simultaneously limiting deleterious effects on peri-prostatic structures. Focal therapy approaches are employed in several oncologic treatment protocols, and have been shown to provide equivalent cancer control for malignancies such as breast cancer and renal cell carcinoma. Efforts to develop a focal therapy approach for prostate cancer have been challenged by several concepts including the multifocal nature of the disease and limited capability of prostate ultrasound and systematic biopsy to reliably localize the site(s) and aggressiveness of disease. Multi-parametric MRI (mpMRI) of the prostate has significantly improved disease localization, spatial demarcation and risk stratification of cancer detected within the prostate. The accuracy of this imaging modality has further enabled the urologist to improve biopsy approaches using targeted biopsy via MRI-ultrasound fusion. From this foundation, an improved delineation of the location of disease has become possible, providing a critical foundation to the development of a focal therapy strategy. This chapter reviews the accuracy of mpMRI for detection of “aggressive“ disease, the accuracy of mpMRI in determining the tumor volume, and the ability of mpMRI to accurately identify the index lesion. While mpMRI provides a critical, first step in developing a strategy for focal therapy, considerable questions remain regarding the relationship between MR identified tumor volume and pathologic tumor volume, the accuracy and utility of mpMRI for treatment surveillance and the optimal role and timing of follow-up mpMRI.

The influence of prostate-specific antigen density on positive and negative predictive values of multiparametric magnetic resonance imaging to detect Gleason score 7-10 prostate cancer in a repeat biopsy setting

OBJECTIVES

To evaluate the influence of prostate-specific antigen density (PSAD) on positive (PPV) and negative (NPV) predictive values of multiparametric magnetic resonance imaging (mpMRI) to detect Gleason score ≥7 cancer in a repeat biopsy setting.

PATIENTS AND METHODS

Retrospective study of 514 men with previous prostate biopsy showing no or Gleason score 6 cancer. All had mpMRI, graded 1-5 on a Likert scale for cancer suspicion, and subsequent targeted and 24-core systematic image-fusion guided transperineal biopsy in 2013-2015. The NPVs and PPVs of mpMRIs for detecting Gleason score ≥7 cancer were calculated (±95% confidence intervals) for PSAD ≤0.1, 0.1-0.2, ≤0.2 and >0.2 ng/mL/mL, and compared by chi-square test for linear trend.

RESULTS

Gleason score ≥7 cancer was detected in 31% of the men. The NPV of Likert 1-2 mpMRI was 0.91 (±0.04) with a PSAD of ≤0.2 ng/mL/mL and 0.71 (±0.16) with a PSAD of >0.2 ng/mL/mL (P = 0.003). For Likert 3 mpMRI, PPV was 0.09 (±0.06) with a PSAD of ≤0.2 ng/mL/mL and 0.44 (±0.19) with a PSAD of >0.2 ng/mL/mL (P = 0.002). PSAD also significantly affected the PPV of Likert 4-5 mpMRI lesions: the PPV was 0.47 (±0.08) with a PSAD of ≤0.2 ng/mL/mL and 0.66 (±0.10) with a PSAD of >0.2 ng/mL/mL (P < 0.001).

CONCLUSION

In a repeat biopsy setting, a PSAD of ≤0.2 ng/mL/mL is associated with low detection of Gleason score ≥7 prostate cancer, not only in men with negative mpMRI, but also in men with equivocal imaging. Surveillance, rather than repeat biopsy, may be appropriate for these men. Conversely, biopsies are indicated in men with a high PSAD, even if an mpMRI shows no suspicious lesion, and in men with an mpMRI suspicious for cancer, even if the PSAD is low.

Utility of Ultrasound in the Diagnosis, Treatment, and Follow-up of Prostate Cancer: State of the Art

Prostate cancer screening currently consists of serum prostate-specific antigen and digital rectal examination, followed by transrectal ultrasound-guided biopsy for diagnostic confirmation. Although the current paradigm of prostate cancer screening has led to a decrease in advanced disease and cancer-related mortality, these techniques have limitations in terms of sensitivity and specificity, resulting in missed cancers that are clinically significant and the overdetection of clinically insignificant cancers. New imaging techniques and technologies are required to improve the detection of prostate cancer. This article summarizes the use of novel ultrasound techniques and technologies in the detection, biopsy, and treatment of prostate cancer.

Prospective comparison of the efficacy of caudal versus periprostatic nerve block, both with intrarectal local anesthesia, during transrectal ultrasonography-guided prostatic needle biopsy

OBJECTIVE

The aim of this study was to compare the effectiveness of caudal block (CB) versus periprostatic nerve block (PPNB), both with intrarectal local anesthesia (IRLA), in reducing pain during transrectal ultrasonography (TRUS)-guided prostatic biopsy.

MATERIALS AND METHODS

This study included 532 patients: 266 patients received CB with IRLA and 266 patients PPNB with IRLA. A visual analogue scale (VAS) was applied to prospectively evaluate pain (1) at induction of anesthesia, (2) at insertion of the TRUS probe, (3) at needle penetration to the prostate, and (4) throughout the biopsy procedure. Pain scores were compared to evaluate differences between groups. The secondary endpoint of serious complication rate was also evaluated. As a subanalysis, the pain scores were compared in patients with high body mass index (BMI ≥25 kg/m²).

RESULTS

Overall, the pain score in the PPNB group was significantly lower than in the CB group at induction of anesthesia (mean ± SD: 2.0 ± 1.9 vs 2.9 ± 2.1, p = .0001) but higher at insertion of the TRUS probe (2.7 ± 2.5 vs 1.9 ± 1.7, p = .009). The pain score did not differ significantly between groups at needle penetration or throughout the biopsy. Univariate analyses indicated no significant association between VAS scores and patient demographics. Overall rates of serious complications did not differ between the two groups (5.6% vs 5.3%, p = .85). In patients with high BMI, the pain score was significantly lower in the PPNB group than in the CB group throughout the procedure (2.5 ± 2.0 vs 3.5 ± 2.5, p = .03).

CONCLUSIONS

Both procedures were equally effective in reducing pain, and the incidence of serious complications was similar. PPNB with IRLA may be more applicable than CB with IRLA in obese patients.

Transperineal template-guided saturation biopsy aimed at sampling one core for each milliliter of prostate volume: 103 cases requiring repeat prostate biopsy

Background

We evaluated the cancer detection rate of prostate cancer using transperineal template-guided saturation biopsy aimed at sampling one core for each milliliter of prostate volume for patients requiring repeated prostate biopsies.

Methods

In total, 103 consecutive patients with repeated prostate biopsies were enrolled in this retrospective study. The number of biopsy cores was defined by prostate volume. In principle, one biopsy core covered 1 mL of prostate volume. We used a prostate brachytherapy template with a 5-mm grid and adopted a transperineal needle biopsy.

Results

The median age, prostate-specific antigen level, and prostate volume were 69 (range, 37–83) years, 9.2 (range, 1.9–107) ng/mL, and 34.7 (range, 18–76.7) mL, respectively. The median number of biopsy cores was 37 (range, 18–75 cores). Fifty-three patients (51.5%) were diagnosed with prostate cancer. The Gleason score was 6, 7, and 8–10 in 24.5, 64.2 and 11.3% patients, respectively. Forty-two patients (79.2%) were diagnosed with clinically significant PCa. Acute urinary retention was detected in 2 patients (1.9%).

Conclusions

Transperineal template-guided saturation biopsy with one core per milliliter of prostate volume helped achieve a high cancer detection rate and high significant cancer detection rate with acceptable biopsy-associated adverse events.

Development and Phantom Validation of a 3-D-Ultrasound-Guided System for Targeting MRI-Visible Lesions During Transrectal Prostate Biopsy

OBJECTIVE

Three- and four-dimensional transrectal ultrasound transducers are now available from most major ultrasound equipment manufacturers, but currently are incorporated into only one commercial prostate biopsy guidance system. Such transducers offer the benefits of rapid volumetric imaging, but can cause substantial measurement distortion in electromagnetic tracking sensors, which are commonly used to enable 3-D navigation. In this paper, we describe the design, development, and validation of a 3-D-ultrasound-guided transrectal prostate biopsy system that employs high-accuracy optical tracking to localize the ultrasound probe and prostate targets in 3-D physical space.

METHODS

The accuracy of the system was validated by evaluating the targeted needle placement error after inserting a biopsy needle to sample planned targets in a phantom using standard 2-D ultrasound guidance versus real-time 3-D guidance provided by the new system.

RESULTS

The overall mean needle-segment-to-target distance error was 3.6 ± 4.0 mm and mean needle-to-target distance was 3.2 ± 2.4 mm.

CONCLUSION

A significant increase in needle placement accuracy was observed when using the 3-D guidance system compared with visual targeting of invisible (virtual) lesions using a standard B-mode ultrasound-guided biopsy technique.

Higher number of transrectal ultrasound guided prostate biopsy cores is associated with higher blood loss and perioperative complications in robot assisted radical prostatectomy

INTRODUCTION

The local inflammatory process after prostate biopsies can have a negative impact on functional outcomes of radical prostatectomy. There is no evidence in literature demonstrating its impact on radical prostatectomy.

OBJECTIVES

To evaluate the impact of the number of TRUS core biopsies in the surgical morbidity and rate of positive margin on robot assisted radical prostatectomy (RARP).

MATERIAL AND METHODS

A prospectively maintained database of 2,054 RARPs in a single institution. Patients were further grouped into 2 groups based on the number of TRUS biopsy cores (G1≤12 cores; G2>12 cores). Multivariable logistic regression model was applied to analyze the impact of number of cores on complications.

RESULTS

A total number of 1,042 patients in the group 1 (≤12 cores) and 1,012 patients in the group 2 (>12 cores) were included. The rate of perioperative complications increased with higher number of biopsies (G1 6.4 vs. G2 8.5%; P=.03), but high grade complication (Clavien 3-4) were similar (G1 1.4 vs. G2 2.2%; P=.16). Positive surgical margin rates were similar in both groups (G1 11.8 vs. 9.98%; P=.2). At the multivariable logistic regression analysis shown that G2 had a 39% (OR 0.645) higher rate to experience perioperative complications during RARP.

CONCLUSION

Higher number of TRUS biopsy cores (>12) is associated to higher blood loss and perioperative complications during RARP. Careful preoperative evaluation for those patients underwent multiple biopsies or saturation protocols is mandatory. Application of longer intervals (>6 weeks) between biopsy and surgery may be advisable to minimize potential risks of surgical complications in patients may benefit from RARP. Further studies are still necessary to confirm these results.

The standards of an ultrasound examination of the prostate gland. Part 2

The paper discusses the rules of the proper performing of the ultrasound examination of the prostate gland. It has been divided into two parts: the general part and the detailed part. The first part presents the necessary requirements related to the ultrasound equipment needed for performing transabdominal and transrectal examinations of the prostate gland. The second part presents the application of the ultrasound examination in benign prostatic hyperplasia, in cases of prostate inflammation and in prostate cancer. Ultrasound examinations applied in the diagnostics of benign prostatic hyperplasia accelerated the diagnosis, facilitated the qualification to surgery and the selection of the treatment method. The assessment of the size of the prostate gland performed using the endorectal ultrasound examination is helpful in making the choice between transurethral electroresection and adenomectomy. In prostate inflammation this examination should be performed with particular gentleness due to pain ailments. The indication for performing the examination in acute inflammation is the suspicion of prostate abscess. In chronic, exacerbating prostatitis it is possible to perform an intraprostatic antibiotic injection. In the recent years increased morbidity and detectability of prostate gland cancer is observed among men. In Poland it ranks second (13%) among diseases occurring in men. The indication for an endorectal examination is the necessity to assess the size of the prostate gland, its configuration, the echostructure in classical ultrasonography, the vascularization in an ultrasound examination performed with power doppler and, if possible, the differences in the gland tissue firmness (consistency) in elastography. The ultrasound examination is used for performing the mapping biopsy of the prostate gland - from routine, strictly defined locations, the targeted biopsy - from locations suspected of neoplastic proliferation and the staging biopsy - from the neurovascular bundles, the seminal vesicles, from the apex of the prostate and from the periprostatic tissue - this type of biopsy is supposed to help in determining local staging of the neoplastic disease. The ultrasound examination is also helpful during the treatment of the neoplasm performed using brachytherapy or using the method of ultrasonic ablation which is still in the phase of clinical trials.

18F-FECH PET/CT to Assess Clinically Significant Disease in Prostate Cancer: Correlation With Maximum and Total Cancer Core Length Obtained via MRI-Guided Template Mapping Biopsies

OBJECTIVE

The objective of this study was to detect clinically significant and insignificant prostate cancer on 18F-fluoroethylcholine (FECH) PET/CT and to correlate findings with transperineal template-guided prostate mapping (TPM) biopsy.

SUBJECTS AND METHODS

Fifty-six lobes of the prostate were analyzed in 28 men who underwent FECH PET/CT and TPM. Whole-body images and pelvic images were acquired at 60 and 90 minutes after tracer administration. FECH PET/CT findings were correlated with TPM. Sensitivity, specificity, positive predictive values, negative predictive values, and AUC of dual phase FECH PET/CT were calculated.

RESULTS

Mean age of the patients was 68.8 years (range, 53-79 years), and mean prostate-specific antigen level was 12.1 ng/mL (range, 0.6-45 ng/mL). Mean maximum cancer core length was 4.4 mm (median, 4 mm; range, 1-14 mm) and mean total cancer core length, 14.6 mm (median, 14.6 mm; range, 1-82 mm). Prostate cancer was identified in 38 lobes with a Gleason score of 6 in five lobes (13%), 7 in 27 lobes (71%), 8 in four lobes (11%), and 9 in two lobes (5%). FECH PET/CT showed findings of prostate cancer in 46/56 lobes (82%). The ranges for maximum standardized uptake value for 60- and 90-minute FECH PET/CT were 1.3-11.4 and 1.2-10.9, respectively. Clinically significant cancer was seen in 30 of 38 positive lobes; eight had clinically insignificant disease. For 60-minute imaging, the sensitivity, specificity, and ROC AUC were 75%, 75%, and 0.746 (95% CI, 0.612-0.853). For 90-minute imaging, the sensitivity, specificity, and ROC AUC were 73.7%, 58.3%, and 0.646 (95% CI, 0.498-0.776). Overall sensitivity, specificity, positive predictive value, and negative predictive value were 95%, 50%, 82.6%, and 80%, respectively.

CONCLUSION

FECH PET/CT can detect prostate cancer and localizes TPM biopsy-proven clinically significant prostate cancer with sensitivity of greater than 89.7%. Of the two imaging durations, 60-minute imaging is more sensitive and specific than 90-minute imaging.

Novel concepts for risk stratification in prostate cancer

Since Partin introduced the analysis of prostate-specific antigen, clinical T-stage and Gleason scores to estimate the risk of progression in men with localised prostate cancer, our understanding of factors that modify this risk has changed drastically. There are now multiple risk stratification tools available, including look-up tables, risk stratification/classification analyses, regression-tree analyses, nomograms and artificial neural networks. Concurrently, descriptions of novel biopsy strategies, imaging modalities and biomarkers are frequently published with the aim of improving risk stratification. With an abundance of new information available, incorporating advances into clinical practice can be confusing. This article aims to outline the major novel concepts in prostate cancer risk stratification for men with biopsy confirmed prostate cancer. We will detail which of these novel techniques and tools are likely to be adopted to aid treatment decisions and enable more accurate post-diagnosis, pretreatment risk stratification.

Clinical performance of transperineal template guided mapping biopsy for therapeutic decision making in low risk prostate cancer

OBJECTIVES

To evaluate the role of Transperineal Template guided Mapping Biopsy (TTMB) in determining the management strategy in patients with low risk prostate cancer (PCa).

METHODS

We retroscpectively evaluated 169 patients who underwent TTMB at our institution from February 2008 to June 2011. Ninety eight of them harbored indolent PCa defined as: Prostate Specific Antigen<10ng/ml, Gleason score 6 or less, clinical stage T2a or less, unilateral disease and a maximum of one third positive cores at first biopsy and<50% of the core involved. TTMB results were analyzed for Gleason score upgrading and upstaging as compared to initial TransRectal UltraSound (TRUS) biopsies and its influence on the change in the treatment decisions.

RESULTS

TTMB detected cancer in 64 (65%) patients. The upgrade, upstage and both were noted in 33% (n=21), 12% (n=8) and 7% (n=5) respectively of the detected cancers. The disease characteristics was similar to initial TRUS in 30 (48%) patients and TTMB was negative in 34 (35%) patients. Prostate volume was significantly smaller in patients with upgrade and/or upstage noted at TTMB (45.4 vs 37.9; P=.03). TTMB results influenced 73.5% of upgraded and/or upstaged patients to receive radical treatment while 81% of the patients with unmodified stage and/or grade continued active surveillance or focal therapy.

CONCLUSIONS

In patients with low risk PCa diagnosed by TRUS, subsequent TTMB demonstrated cancer upgrade and/or upstage in about one-third of the patients and resulted in eventual change in treatment decision.

Biparametric 3T Magnetic Resonance Imaging for prostatic cancer detection in a biopsy-naïve patient population: a further improvement of PI-RADS v2?

OBJECTIVES

To prospectively determine the diagnostic accuracy of a biparametric 3T magnetic resonance imaging protocol (BP-MRI) for prostatic cancer detection, compared to a multiparametric MRI protocol (MP-MRI), in a biopsy naïve patient population.

METHODS

Eighty-two untreated patients (mean age 65±7.6years) with clinical suspicion of prostate cancer and/or altered prostate-specific antigen (PSA) levels underwent a MP-MRI, including T2-weighted imaging, diffusion-weighted imaging (with the correspondent apparent diffusion coefficient maps) and dynamic contrast enhanced sequence, followed by prostate biopsy. Two radiologists reviewed both the BP-MRI and the MP-MRI protocols to establish a radiological diagnosis. Receiver operating characteristics curves were obtained to determine the diagnostic performance of the two protocols.

RESULTS

The mean PSA level was 8.8±8.1ng/ml. A total of 34 prostatic tumors were identified, with a Gleason score that ranged from 3+3 to 5+4. Of these 34 tumors, 29 were located within the peripheral zone and 5 in the transitional zone. BP-MRI and MP-MRI showed a similar performance in terms of overall diagnostic accuracy, with an area under the curve of 0.91 and 0.93, respectively (p=n.s.).

CONCLUSIONS

BP-MRI prostate protocol is feasible for prostatic cancer detection compared to a standard MP-MRI protocol, requiring a shorter acquisition and interpretation time, with comparable diagnostic accuracy to the conventional protocol, without the administration of gadolinium-based contrast agent.

Developing a new score system for patients with PSA ranging from 4 to 20 ng/mL to improve the accuracy of PCa detection

Objective

To develop a new score system for patients with prostate specific antigen (PSA) ranging from 4 to 20 ng/mL to improve the accuracy of prostate cancer (PCa) detection, and to evaluate it with receiver operating characteristic curve.

Methods

A total of 797 patients (208 with prostate cancer) with total PSA 4–20 ng/mL who had undergone transrectal ultrasound (TRUS)-guided 12 + 1-core prostate biopsy during Sept. 2009–Jan. 2013 were retrospectively evaluated in the study. Age, PSA, fPSA, PV, f/T, PSAD, DRE findings and ultrasound findings were considered as predictive factors and tested by logistic regression. Predictors with P < 0.05 were selected to develop a new score system.

Results

Age, PSA, PV, f/T, DRE findings, and hypoechoic in ultrasound were selected in our new score system. The risk of PCa increased with the score. From 0 to 6, the risk was 2.0, 8.4, 13.9, 33.5, 63.8, 75.0 and 100.0 % respectively. Area under curve (AUC) of our new score system was 0.804, which was significantly higher than The Prostate Cancer Risk Calculator by Stichting Wetenschappelijk Onderzoek Prostaatkanker (SWOP) (0.720, P = 0.002).

Conclusions

We developed a new simple score system for patients with PSA ranging from 4 to 20 ng/mL to improve the accuracy of PCa detection.

Prostate MRI - an update for the referring urologist

INTRODUCTION

Prostate MRI is a new and important tool which has a role in prostate cancer guidelines worldwide. The amount of articles published and studies currently taking place on the subject requires urologists to understand how the examination is performed and its possible applications. This article explains prostate MRI and standardized reporting schemes, as well as its applications according to patients' staging and history.

MATERIAL AND METHODS

The use of prostate MRI prior to biopsy, MRI-guided biopsy and its use in active surveillance, surgery staging and planning, as well as in cases with biochemical recurrence are discussed.

RESULTS

The application of prostate MRI are not limited to initial diagnosis, but also has a developing role in biopsy and planning further treatment. Recently, its diagnostic applications have been included in EAU prostate cancer guidelines and new applications are in development.

CONCLUSIONS

Practicing urologists are seeing an emerging role of MRI in prostate cancer. Its current and future applications may have an impact on patient care, which mandates healthcare professionals to be vigilant about the method's new developments.