Impact of multiparametric MRI and MRI-targeted biopsy on pre-therapeutic risk assessment in prostate cancer patients candidate for radical prostatectomy

Current magnetic resonance imaging-based diagnostic strategies for prostate cancer

Recent developments in multiparametric MRI and MRI-targeted biopsy have made it possible to detect clinically significant cancers more accurately and efficiently than ever before. Furthermore, software that enables easy MRI/US image fusion has been developed and is already available on the market, and this has provided a tailwind for the spread of MRI-based prostate cancer diagnostic strategies. Such precise diagnosis of prostate cancer localization is essential for highly accurate focal therapy. In addition, a recent large-scale study applying MRI to community screening for prostate cancer has reported its usefulness. By contrast, concerns about overdiagnosis and overtreatment, the existence of inter-reader variability in MRI diagnosis, and issues with current MRI-targeted biopsy have emerged. In this article, we review the development of multiparametric MRI and MRI-targeted biopsy to date and the current issues and discuss future directions.

A preoperative magnetic resonance imaging-based model to predict biochemical failure after radical prostatectomy

To investigate if a magnetic resonance imaging (MRI)-based model reduced postoperative biochemical failure (BF) incidence in patients with prostate cancer (PCa). From June 2018 to January 2020, we retrospectively analyzed 967 patients who underwent prostate bi-parametric MRI and radical prostatectomy (RP). After inclusion criteria were applied, 446 patients were randomized into research (n = 335) and validation cohorts (n = 111) at a 3:1 ratio. In addition to clinical variables, MRI models also included MRI parameters. The area under the curve (AUC) of receiver operating characteristic and decision curves were analyzed. The risk of postoperative BF, defined as persistently high or re-elevated prostate serum antigen (PSA) levels in patients with PCa with no clinical recurrence. In the research (age 69 [63-74] years) and validation cohorts (age 69 [64-74] years), the postoperative BF incidence was 22.39% and 27.02%, respectively. In the research cohort, the AUC of baseline and MRI models was 0.780 and 0.857, respectively, with a significant difference (P < 0.05). Validation cohort results were consistent (0.753 vs. 0.865, P < 0.05). At a 20% risk threshold, the false positive rate in the MRI model was lower when compared with the baseline model (31% [95% confidence interval (CI): 9-39%] vs. 44% [95% CI: 15-64%]), with the true positive rate only decreasing by a little (83% [95% CI: 63-94%] vs. 87% [95% CI: 75-100%]). 32 of 100 RPs can been performed, with no raise in quantity of patients with missed BF. We developed and verified a MRI-based model to predict BF incidence in patients after RP using preoperative clinical and MRI-related variables. This model could be used in clinical settings.

Magnetic Resonance Imaging-Targeted Biopsy and Pretherapeutic Prostate Cancer Risk Assessment: a Systematic Review: Biopsie ciblée par Imagerie par résonance magnétique et évaluation pré-thérapeutique du risque de cancer de la prostate : revue systématique

INTRODUCTION

Multiparametric magnetic resonance imaging (MRI) has been included in prostate cancer (PCa) diagnostic pathway and may improve disease characterization. The aim of this systematic review is to assess the added value of MRI-targeted biopsy (TB) in pre-therapeutic risk assessment models over existing tools based on systematic biopsy (SB) for localized PCa.

EVIDENCE ACQUISITION

A systematic search was conducted using Pubmed (Medline), Scopus and ScienceDirect databases according to Preferred Reporting Items for Systematic Reviews and Meta-analysis (PRISMA) statement. We included studies through October 2021 reporting on TB in pretherapeutic risk assessment models.

EVIDENCE SYNTHESIS

We identified 24 eligible studies including 24'237 patients for the systematic review. All included studies were retrospective and conducted in patients undergoing radical prostatectomy. Nine studies reported on the risk of extraprostatic extension, seven on the risk of lymph node invasion, three on the risk of biochemical recurrence and nine on the improvement of PCa risk stratification. Overall, the combination of TB with imaging, clinical and biochemical parameters outperformed current pretherapeutic risk assessment models. External validation studies are lacking for certain endpoints and the absence of standardization among TB protocols, including number of TB cores and fusion systems, may limit the generalizability of the results.

CONCLUSION

TB should be incorporated in pretherapeutic risk assessment models to improve clinical decision making. Further high-quality studies are required to determine models' generalizability while there is an urgent need to reach consensus on a standardized TB protocol. Long-term outcomes after treatment are also awaited to confirm the superiority of such models over classical risk classifications only based on SB. © 2022 Elsevier Masson SAS. All rights reserved.

Comparison of Multi-Parametric MRI of the Prostate to 3D Prostate Computer Aided Designs and 3D-Printed Prostate Models for Pre-Operative Planning of Radical Prostatectomies: A Pilot Study

OBJECTIVE

To evaluate the use of 3D computed aided designs and 3D-printed models as pre-operative planning tools for urologists, in addition to radiologist interpreted mp-MRIS, prior to radical prostatectomy procedures.

METHODS

Ten patients with biopsy-positive lesions detected on mp-MRI were retrospectively selected. Radiologists identified lesion locations using a Prostate Imaging-Reporting and Data System (PI-RADS) map and segmented the prostate, lesion(s), and surrounding anatomy to create 3D-CADs and 3D-printed models for each patient. 6 uro-oncologists randomly reviewed three modalities (mp-MRI, 3D-CAD, and 3D-printed models) for each patient and identified lesion locations which were graded for accuracy against the radiologists' answers. Questionnaires assessed decision confidence, ease-of-interpretation, and usefulness for preoperative planning for each modality.

RESULTS

Using 3D-CADs and 3D-printed models compared to mp-MRI, urologists were 2.4x and 2.8x more accurate at identifying the lesion(s), 2.7x and 3.2x faster, 1.6x and 1.63x more confident, and reported it was 1.6x and 1.7x easier to interpret. 3D-CADs and 3D-printed models were reported significantly more useful for overall pre-operative planning, identifying lesion location(s), determining degree of nerve sparing, obtaining negative margins, and patient counseling. Sub-analysis showed 3D-printed models demonstrated significant improvements in ease-of-interpretation, speed, usefulness for obtaining negative margins, and patient counseling compared to 3D-CADs.

CONCLUSION

3D-CADs and 3D-printed models are useful adjuncts to mp-MRI in providing urologists with more practical, accurate, and efficient pre-operative planning.

Risk Stratification of Patients Candidate to Radical Prostatectomy Based on Clinical and Multiparametric Magnetic Resonance Imaging Parameters: Development and External Validation of Novel Risk Groups

BACKGROUND

Despite the key importance of magnetic resonance imaging (MRI) parameters, risk classification systems for biochemical recurrence (BCR) in prostate cancer (PCa) patients treated with radical prostatectomy (RP) are still based on clinical variables alone.

OBJECTIVE

We aimed at developing and validating a novel classification integrating clinical and radiological parameters.

DESIGN, SETTING, AND PARTICIPANTS

A retrospective multicenter cohort study was conducted between 2014 and 2020 across seven academic international referral centers. A total of 2565 patients treated with RP for PCa were identified.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

Early BCR was defined as two prostate-specific antigen (PSA) values of ≥0.2 ng/ml within 3 yr after RP. Kaplan-Meier and Cox regressions tested time and predictors of BCR. Development and validation cohorts were generated from the overall patient sample. A model predicting early BCR based on Cox-derived coefficients represented the basis for a nomogram that was validated externally. Predictors consisted of PSA, biopsy grade group, MRI stage, and the maximum diameter of lesion at MRI. Novel risk categories were then identified. The Harrel's concordance index (c-index) compared the accuracy of our risk stratification with the European Association of Urology (EAU), Cancer of the Prostate Risk Assessment (CAPRA), and International Staging Collaboration for Cancer of the Prostate (STAR-CAP) risk groups in predicting early BCR.

RESULTS AND LIMITATIONS

Overall, 200 (8%), 1834 (71%), and 531 (21%) had low-, intermediate-, and high-risk disease according to the EAU risk groups. The 3-yr overall BCR-free survival rate was 84%. No differences were observed in the 3-yr BCR-free survival between EAU low- and intermediate-risk groups (88% vs 87%; p = 0.1). The novel nomogram depicted optimal discrimination at external validation (c-index 78%). Four new risk categories were identified based on the predictors included in the Cox-based nomogram. This new risk classification had higher accuracy in predicting early BCR (c-index 70%) than the EAU, CAPRA, and STAR-CAP risk classifications (c-index 64%, 63%, and 67%, respectively).

CONCLUSIONS

We developed and externally validated four novel categories based on clinical and radiological parameters to predict early BCR. This novel classification exhibited higher accuracy than the available tools.

PATIENT SUMMARY

Our novel and straightforward risk classification outperformed currently available preoperative risk tools and should, therefore, assist physicians in preoperative counseling of men candidate to radical treatment for prostate cancer.

Evaluation of how users interface with holographic augmented reality surgical scenes: Interactive planning MR-Guided prostate biopsies

BACKGROUND

User interfaces play a vital role in the planning and execution of an interventional procedure. The objective of this study is to investigate the effect of using different user interfaces for planning transrectal robot-assisted MR-guided prostate biopsy (MRgPBx) in an augmented reality (AR) environment.

METHOD

End-user studies were conducted by simulating an MRgPBx system with end- and side-firing modes. The information from the system to the operator was rendered on HoloLens as an output interface. Joystick, mouse/keyboard, and holographic menus were used as input interfaces to the system.

RESULTS

The studies indicated that using a joystick improved the interactive capacity and enabled operator to plan MRgPBx in less time. It efficiently captures the operator's commands to manipulate the augmented environment representing the state of MRgPBx system.

CONCLUSIONS

The study demonstrates an alternative to conventional input interfaces to interact and manipulate an AR environment within the context of MRgPBx planning.

A narrative review of pelvic lymph node dissection in prostate cancer

Pelvic lymph node dissection (PLND) is an important component in the staging and prognostication of prostate cancer. We performed a narrative review to assess the literature surrounding PLND: (I) the current guideline recommendations and contemporary utilization, (II) the calculation of patient-specific risk to perform PLND using available nomograms, (III) to review the extent of dissection, and its associated outcomes and complications. Due to the improved lymph node yield, better staging, and theoretical improvement in the control of micro-metastatic disease, guidelines have supported the use of (extended-) PLND in patients deemed to be at intermediate or high risk of lymph node involvement (often at a threshold of 5% on modern risk nomograms). However, in practice, real-world utilization of PLND varies considerably due to multiple reasons. Conflicting evidence persists with no clear oncological benefit to PLND, and a small, but important, risk of morbidity. Complications are rare, but include lymphoceles; thromboembolic events; and more rarely, obturator nerve, vascular, and ureteric injury. Furthermore, changing disease incidence and stage migration in the context of earlier detection overall have led to a decreased risk of nodal disease. The trade-offs between the benefits, harms, and risk tolerance/threshold must be carefully considered between each patient and their clinician.

Technical Refinements in Superextended Robot-assisted Radical Prostatectomy for Locally Advanced Prostate Cancer Patients at Multiparametric Magnetic Resonance Imaging

BACKGROUND

The feasibility and efficacy of robot-assisted radical prostatectomy (RARP) in locally advanced prostate cancer (PCa) patients with iT3 lesion at magnetic resonance imaging (MRI) are currently not explored.

OBJECTIVE

To describe our revised RARP technique (ie, superextended RARP [SE-RARP]) for PCa patients with posterior iT3a or iT3b at MRI.

DESIGN, SETTING, AND PARTICIPANTS

Data from 89 patients with posterior iT3a or T3b disease who underwent SE-RARP at a single high-volume centre between 2015 and 2018 were analysed.

SURGICAL PROCEDURE

RARP was performed using a DaVinci Xi system. The surgical approach provided an inter- or extrafascial RARP where Denonvilliers' fascia and perirectal fat were dissected free and left on the posterior surface of the seminal vesicles.

MEASUREMENTS

Perioperative outcomes, and intra- and postoperative complications were assessed. Postoperative outcomes were assessed in patients with complete follow-up data (n = 78). Biochemical recurrence (BCR) was defined as two consecutive prostate-specific antigen values of ≥0.2 ng/ml. Urinary continence (UC) recovery was defined as the use of zero or one safety pad. Kaplan-Meier and multivariable Cox regression models were used.

RESULTS AND LIMITATIONS

The median operative time, blood loss, and length of stay were 204 min, 300 ml, and 5 d, respectively. The median bladder catheterisation time was 5 d. Overall, 28%, 28%, and 27% of patients had pathological grade group (GG) 4-5, pT3b, and positive surgical margins (PSMs), respectively. Three patients (3.4%) experienced intraoperative complications. Among patients with available follow-up data (n = 78), 14 (18%) experienced 30-d postoperative complications. The median follow-up was 19 mo. Overall, 11 patients received additional treatment. At 2 yr of follow-up, BCR-free and additional treatment-free survival were 55% and 66%, respectively. Pathological GG 4-5 (hazard ratio [HR] 3.2) and PSM (HR 5.8) were independent predictors of recurrence, as well as of additional treatment use (HR 5.6 for GG 4-5 and 5.2 for PSM). The 1-yr UC recovery was 84%.

CONCLUSIONS

We presented our revised RARP technique applicable to patients with posterior iT3a or iT3b at preoperative MRI. This technique is associated with good morbidity and continence recovery rates, and might guarantee biochemical control of the disease and postpone the use of additional treatments in patients with low-grade and negative surgical margins.

PATIENT SUMMARY

A revised robot-assisted radical prostatectomy technique applicable to prostate cancer patients with posterior iT3a or iT3b lesion at magnetic resonance imaging was described. This novel technique is feasible and safe in expert hands.

Predicting the Probability of Lymph Node Involvement with Prostate Cancer Nomograms: Can We Trust the Prediction Models?

Introduction Prediction of lymph node involvement (LNI) is of paramount importance for patients with prostate cancer (PCa) undergoing radical prostatectomy (RP). Multiple statistical models predicting LNI have been developed to support clinical decision-making regarding the need of extended pelvic lymph node dissection (ePLND). Our aim is to evaluate the prediction ability of the best-performing prediction tools for LNI in PCa in a Latin-American population.

Methods Clinicopathological data of 830 patients with PCa who underwent RP and ePLND between 2007 and 2018 was obtained. Only data from patients who had ≥ 10 lymph nodes (LNs) harvested were included (n = 576 patients). Four prediction models were validated using this cohort: The Memorial Sloan Kettering Cancer Center (MSKCC) web calculator, Briganti v.2017, Yale formula and Partin tables v.2016. The performance of the prediction tools was assessed using the area under the receiver operating characteristic (ROC) curve (AUC).

Results The median age was 61 years old (interquartile range [IQR] 56–66), the median Prostate specific antigen (PSA) was 6,81 ng/mL (IQR 4,8–10,1) and the median of LNs harvested was 17 (IQR 13–23), and LNI was identified in 53 patients (9.3%). Predictions from the 2017 Briganti nomogram AUC (0.85) and the Yale formula AUC (0.85) were the most accurate; MSKCC and 2016 Partin tables AUC were both 0,84.

Conclusion There was no significant difference in the performance of the four validated prediction tools in a Latin-American population compared with the European or North American patients in whom these tools have been validated. Among the 4 models, the Briganti v.2017 and Yale formula yielded the best results, but the AUC overlapped with the other validated models.

Prognostic Implications of Multiparametric Magnetic Resonance Imaging and Concomitant Systematic Biopsy in Predicting Biochemical Recurrence After Radical Prostatectomy in Prostate Cancer Patients Diagnosed with Magnetic Resonance Imaging-targeted Biopsy

BACKGROUND

The prognostic role of multiparametric magnetic resonance imaging (mpMRI) and systematic biopsy in predicting biochemical recurrence (BCR) after radical prostatectomy (RP) in prostate cancer (PCa) patients has not been addressed yet.

OBJECTIVE

To develop a risk tool predicting BCR after RP in patients diagnosed with magnetic resonance imaging (MRI)-targeted biopsy.

DESIGN, SETTING, AND PARTICIPANTS

A total of 804 patients with a clinical suspicion of PCa and positive mpMRI diagnosed with MRI-targeted plus concomitant systematic biopsy treated with RP were identified.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSES

The outcome was represented by BCR defined as two prostate-specific antigen (PSA) values ≥0.2ng/ml after surgery. Multivariable Cox regression analyses assessed the predictors of BCR. A risk tool model based on imaging and biopsy parameters was developed and validated internally. The c-index, calibration plot, and decision curve analyses were used to assess discrimination, calibration, and the net benefit associated with its use in predicting BCR at 36 mo.

RESULTS AND LIMITATIONS

Median (interquartile range) follow-up was 28 (25-29) mo, and 89 patients experienced BCR. The 36-mo BCR-free survival rate was 89%. The maximum diameter of the index lesion and seminal vesicle invasion (SVI) at mpMRI as well as the presence of clinically significant PCa at systematic biopsy (defined as a grade group of >2) were associated with BCR (all p≤0.03). A model based on PSA, Prostate Imaging Reporting and Data System score, SVI at mpMRI, diameter of the index lesion, grade group at MRI-targeted biopsy, and clinically significant PCa at systematic biopsy achieved the highest discrimination (77%) among all clinical models, as well as the European Association of Urology risk groups (62%) and the Cancer of the Prostate Risk Assessment (CAPRA) score (60%). This tool was characterized by excellent calibration at internal validation and the highest net benefit when predicting BCR for the threshold risk between 0% and 30%.

CONCLUSIONS

The adoption of predictive models accounting for mpMRI and MRI-targeted biopsy-derived variables and concomitant systematic biopsy would improve clinicians' ability to identify patients at a higher risk of early recurrence after surgery.

PATIENT SUMMARY

The use of information obtained at multiparametric magnetic resonance imaging (mpMRI), and MRI-targeted and concomitant systematic biopsy would improve clinicians' ability to identify prostate cancer patients at a higher risk of experiencing early biochemical recurrence after surgery.

All change in the prostate cancer diagnostic pathway

Following detection of high levels of serum prostate-specific antigen, many men are advised to have transrectal ultrasound-guided biopsy in an attempt to locate a cancer. This nontargeted approach lacks accuracy and carries a small risk of potentially life-threatening sepsis. Worse still, it can detect clinically insignificant cancer cells, which are unlikely to be the origin of advanced-stage disease. The detection of these indolent cancer cells has led to overdiagnosis, one of the major problems of contemporary medicine, whereby many men with clinically insignificant disease are advised to undergo unnecessary radical surgery or radiotherapy. Advances in imaging and biomarker discovery have led to a revolution in prostate cancer diagnosis, and nontargeted prostate biopsies should become obsolete. In this Perspective article, we describe the current diagnostic pathway for prostate cancer, which relies on nontargeted biopsies, and the problems linked to this pathway. We then discuss the utility of prebiopsy multiparametric MRI and novel tumour markers. Finally, we comment on how the incorporation of these advances into a new diagnostic pathway will affect the current risk-stratification system and explore future challenges.

Improvement of the intermediate risk prostate cancer sub-classification by integrating MRI and fusion biopsy features

INTRODUCTION

Treatment decision-making for intermediate-risk prostate cancer (CaP) is mainly based on grade and tumor involvement on systematic biopsy. We aimed to assess the added value of multi-parametric magnetic resonance imaging (mpMRI) and targeted biopsy (TB) features for predicting final pathology and for improving the well-established favourable/unfavourable systematic biopsy-based sub-classification.

MATERIALS AND METHODS

From a prospective database of 377 intermediate risk CaP cases, we evaluated the performance of the standard intermediate risk classification (IRC), and the predictive factors for unfavourable disease on final pathology aiming to build a new model. Overall unfavourable disease (OUD) was defined by any pT3-4 and/or pN1 and/or grade group (GG) ≥ 3.

RESULTS

The standard IRC was found to be predictive for unfavourable disease in this population. However, in multivariable analysis regression, ECE on mpMRI and GG ≥3 on TB remained the 2 independent predictive factors for OUD disease (HR = 2.7, P = 0.032, and HR = 2.41, P = 0.01, respectively). By using the new IRC in which unfavorable risk was defined by ECE on mpMRI and/or GG ≥3 on TB, the proportion of unfavorable cases decreased from 62.3% to 34.1% while better predicting unfavorable disease in RP speciments. The new model displayed a better accuracy than the standard IRC for predicting OUD (AUC: 0.66 vs. 0.55).

CONCLUSIONS

The integration of imaging and TB features drastically improves the intermediate risk sub-classification performance and better discriminates the unfavourable risk group that could benefit from more aggressive therapy such as neo-adjuvant and/or adjuvant treatment, and the favourable group that could avoid over-treatment. External validation in other datasets is needed.

Decreased accuracy of the prostate cancer EAU risk group classification in the era of imaging-guided diagnostic pathway: proposal for a new classification based on MRI-targeted biopsies and early oncologic outcomes after surgery

PURPOSE

To assess the performance of EAU risk classification in PCa patients according to the biopsy pathway (standard versus MRI guided) and to develop a new, more accurate, targeted biopsy (TB)-based classification.

MATERIALS AND METHODS

We included 1345 patients consecutively operated by radical prostatectomy (RP) since 2014, when MRI and TB were introduced in the diagnostic pathway. Patients underwent systematic biopsy (SB) only (n = 819) or SB and TB (n = 526) prior to RP during the same time period. Pathological and biochemical outcomes were compared between PCa men undergoing SB (SB cohort) and a combination of TB and SB (TB cohort). Kaplan-Meier and Cox regression models were used to assess biochemical recurrence-free survival (RFS).

RESULTS

Both cohorts were comparable regarding final pathology and RFS (p = 0.538). The EAU risk classification accurately predicted outcomes in SB cohort, but did not significantly separate low from intermediate risk in TB cohort (p = 0.791). In TB cohort, the new proposed three-group risk classification significantly improved the recurrence risk prediction compared with the EAU risk classification: HR 4 (versus HR 1.2, p = 0.009) for intermediate, and HR 15 (versus HR 6.5, p < 0.001) in high-risk groups, respectively. A fourth group defining very high-risk cases (≥ T2c clinical stage or grade group 5) was also proposed.

CONCLUSIONS

The new classification integrating TB findings we propose meaningfully improves the recurrence prediction after surgery in patients undergoing a TB-based diagnostic pathway, compared with standard EAU risk classification which is still relevant for patients undergoing only SB. External validation is needed.

Incorporating mpMRI biopsy data into established pre-RP nomograms: potential impact of an increasingly common clinical scenario

Background:

We examine the practical application of multiparametric MRI (mpMRI) prostate biopsy data using established pre-RP nomograms and its potential implications on RP intraoperative decision-making. We hypothesize that current nomograms are suboptimal in predicting outcomes with mpMRI targeted biopsy (TBx) data.

Materials and methods:

Patients who underwent mpMRI-based TBx prior to RP were assessed using the MSKCC and Briganti nomograms with the following iterations: (1) Targeted (T) (targeted only), (2) Targeted and Systematic (TS) and (3) Targeted Augmented (TA) (targeted core data; assumed negative systematic cores for 12 total cores). Nomogram outcomes, lymph node involvement (LNI), extracapsular extension (ECE), organ-confined disease (OCD), seminal vesicle invasion (SVI), were compared across iterations. Clinically significant impact on management was defined as a change in LNI risk above or below 2% (Δ2) or 5% (Δ5).

Results:

A total of 217 men met inclusion criteria. Overall, the TA iteration had more conservative nomogram outcomes than the T. Moreover, TA better predicted RP pathology for all four outcomes when compared with the T. In the entire cohort, Δ2 and Δ5 were 16.6–25.8% and 20.3–39.2%, respectively. In the subset of 190 patients with targeted and systematic cores, TA was a better approximation of TS outcomes than T in 71% (MSKCC) and 82% (Briganti) of patients.

Conclusion:

In established pre-RP nomograms, mpMRI-based TBx often yield variable and discordant results when compared with systematic biopsies. Future nomograms must better incorporate mpMRI TBx core data. In the interim, augmenting TBx data may serve to bridge the gap.

Role of MRI in planning radical prostatectomy: what is the added value?

INTRODUCTION

The goal of radical prostatectomy is to eradicate oncological disease while achieving the best possible functional outcomes. In this regard, nerve sparing offers a greater chance of recovering potency after surgery. Accurately locating prostate cancer foci is instrumental for identifying good candidates for this approach whilst maintaining safe oncological margins. In addition to this, the length of membranous urethra is an independent predictor of time to, and extent of, continence recovery. The introduction of Mp-MRI allows visualising malignant tissue within the prostate gland, which could lead to image-directed surgery planning as with other solid-organ cancers such as kidney, pancreas, breast or testes.

METHODS

A narrative review of the available literature was performed.

RESULTS

Mp-MRI demonstrated moderate sensitivity and high specificity to detect extra-capsular extension, seminal vesicle involvement or T3 stage. Measurements of membranous urethral length have shown to be useful in predicting probability of achieving continence after surgery. Furthermore, image-guided surgery has shown to be accurate to determine surgical planes to safely preserve neurovascular bundles.

CONCLUSION

The use of Mp-MRI for pre-surgical planning introduces a new scenario where the previously homogeneous radical prostatectomy can be tailored to suit patient and tumour features. This has the potential to improve functional outcomes whilst not compromising on surgical margins. Moreover, the introduction of Mp-MRI increases the ability to predict functional outcomes after surgery and allows for a more accurate local staging. This in turn provides more information to both patients and clinicians in the decision-making process regarding treatment.

There Is No Way to Avoid Systematic Prostate Biopsies in Addition to Multiparametric Magnetic Resonance Imaging Targeted Biopsies

BACKGROUND

Whether or not adding systematic biopsies (transrectal ultrasound-guided biopsy [TRUS-Bx]) to targeted cores in patients with a lesion detected at multiparametric magnetic resonance imaging (mpMRI) is still a debated topic.

OBJECTIVE

To identify patients who can avoid TRUS-Bx at the time of mpMRI targeted biopsy (MRI-TBx) relying on individual patient probability to harbour clinically significant prostate cancer (csPCa) outside the index lesion (IL).

DESIGN, SETTING, AND PARTICIPANTS

A total of 339 European and 441 North American patients underwent fusion MRI-TBx and concomitant TRUS-Bx at two tertiary care referral centres between 2013 and 2017.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

The study outcome was csPCa, defined as a Gleason score at biopsy of ≥7, outside the IL. Multivariable logistic regression analyses (MVAs) were performed to develop a predictive model for the study outcome. Multivariable-derived coefficients were used to develop a novel risk calculator in each cohort. The models were evaluated using the area under the curve (AUC), calibration plot, and decision-curve analyses.

RESULTS AND LIMITATIONS

In the European cohort, csPCa detection rate was 55%. The csPCa detection rate for TRUS-Bx was 41%. At MVAs, prostate volume, previous negative biopsy, and Prostate Imaging Reporting and Data System versions 4 and 5 were independent predictors for the presence of csPCa outside the IL. The multivariable model had an AUC of 0.78. Omitting TRUS-Bx in patients with a calculated risk of <15% would have spared 16% of TRUS-Bx at the cost of missing 7% of csPCa. Similar findings were obtained when the same analyses were performed in the North American cohort. No net benefit was observed for low-threshold probabilities (<15%) of the each model relative to the standard of care (performing TRUS-Bx in addition to MRI-TBx to all patients) in both cohorts. The study is limited by its retrospective design.

CONCLUSIONS

We failed to identify those patients who might safely benefit from MRI-TBx alone. The combination of MRI-TBx and TRUS-Bx should strongly be considered the best available approach.

PATIENT SUMMARY

In the presence of positive multiparametric magnetic resonance imaging (mpMRI) of the prostate, physicians should always perform systematic sampling of the prostate in addition to mpMRI targeted biopsy.

Controversies in MR targeted biopsy: alone or combined, cognitive versus software-based fusion, transrectal versus transperineal approach?

PURPOSE

To review the evidence addressing current controversies around prostate biopsy. Specific questions explored were (1) mpMRI targeted (TgBx) alone versus combined with systematic (SBx) biopsy; (2) cognitive versus software-based targeted biopsy; (3) transrectal or transperineal route (TP).

METHODS

We performed a literature search of peer-reviewed English language articles using PubMed and the words "prostate" AND "biopsy". Web search was implemented by manual search.

RESULTS

Prostate mpMRI is revolutionizing prostate cancer (PCa) diagnosis, and TgBx improves the detection of clinically significant (cs) PCa compared to SBx alone. The utility of combining SBx-TgBx is variable, but in non-expert centres the two should be combined to overcome learning curve-limitations. Whether SBx should be maintained in expert centres depends on what rate of missed cancer the urological community and patients are prone to accept; this has implications for insignificant cancer diagnosis as well. TgBx may be more precise using a software-based-approach despite cognitive TgBx proved non-inferior in some studies, and may be used for large accessible lesions. TP-biopsies are feasible in an in-office setting. Avoidance of the rectum and accessibility of virtually all prostate areas are attractive features. However, this has to be balanced with local setting and resources implications. Ongoing trials will shed light on unsolved issues.

CONCLUSION

The prostate biopsy strategy should be tailored to local expertise, needs and resources availability. Targeted biopsy enhance the ratio between cs and insignificant cancer diagnosis, although some csPCa might be missed. Software-based TgBx are likely to be more precise, especially for new users, although the additional cost might be not justified in all cases. TPBx have ideal attributes for performing TgBx and avoiding infection, although this has resources implications.

Tissue-based multigene expression tests for pretreatment prostate cancer risk assessment: current status and future perspectives

Prostate cancer is a highly prevalent disease with ample spectrum of aggressiveness and treatment options. Low-risk disease can be safely managed by nonintervention strategies, such as active surveillance; however, accurate risk assessment is warranted. Molecular tests have been developed and validated to complement standard clinicopathological parameters and help to improve risk stratification in prostate cancer. Herein, we review selected tissue-based assays, including genomic prostate score, cell cycle progression score and genomic classifier, with particular emphasis on their role in patient risk assessment in a pretreatment setting, in view of their current or potential utilization in active surveillance.