Do contemporary imaging and biopsy techniques reliably identify unilateral prostate cancer? Implications for hemiablation patient selection

Predictors of Contralateral Disease in Men With Unilateral Lesions on Multiparametric Magnetic Resonance Imaging

OBJECTIVE

To evaluate predictors of contralateral clinically significant prostate cancer (csPCa) in men with biopsy-proven unilateral lesions on magnetic resonance imaging (MRI).

METHODS

We retrospectively identified men with no prior diagnosis of PCa with unilateral biopsy-confirmed csPCa within PI-RADS 2-5 lesions within our institutional biopsy database. Multivariate logistic regression was used to identify clinical predictors of contralateral disease.

RESULTS

Four hundred ninety men met study inclusion criteria, of which 385 men (78.6%) had no contralateral csPCa and 105 men (21.4%) had contralateral csPCa (Fig. 1). Prior negative biopsy (OR 0.34 [0.14, 0.75], P = .012), prostate-specific antigen density (OR 18.8 [2.77, 249], P = .017), and tumor location in the transverse plane ("Posterior": OR 1.93 [1.02, 3.87], P = .048; "Throughout Transverse Plane": OR 6.56 [2.26, 19.6], P < .001) were significantly associated with contralateral csPCa in multivariate logistic regression models. However, there appear to be no attributes within the MRI-targeted tumor that reliably predict contralateral csPCa (Table 2).

CONCLUSION

Approximately 20% of men with unilateral MRI findings and csPCa on targeted biopsy were found to have contralateral csPCa on systematic biopsy (SB). Prior negative biopsy was associated with a decreased odds of contralateral csPCa. Prostate-specific antigen density and tumor in the posterior aspect of or throughout the transverse plane were associated with increased odds of contralateral csPCA. Consideration of these clinical factors may afford an opportunity to only use SB in cases in which the odds of contralateral csPCa are high.

Artificial Intelligence Improves the Ability of Physicians to Identify Prostate Cancer Extent

PURPOSE

Defining prostate cancer contours is a complex task, undermining the efficacy of interventions such as focal therapy. A multireader multicase study compared physicians' performance using artificial intelligence (AI) vs standard-of-care methods for tumor delineation.

MATERIALS AND METHODS

Cases were interpreted by 7 urologists and 3 radiologists from 5 institutions with 2 to 23 years of experience. Each reader evaluated 50 prostatectomy cases retrospectively eligible for focal therapy. Each case included a T2-weighted MRI, contours of the prostate and region(s) of interest suspicious for cancer, and a biopsy report. First, readers defined cancer contours cognitively, manually delineating tumor boundaries to encapsulate all clinically significant disease. Then, after ≥ 4 weeks, readers contoured the same cases using AI software. Using tumor boundaries on whole-mount histopathology slides as ground truth, AI-assisted, cognitively-defined, and hemigland cancer contours were evaluated. Primary outcome measures were the accuracy and negative margin rate of cancer contours. All statistical analyses were performed using generalized estimating equations.

RESULTS

The balanced accuracy (mean of voxel-wise sensitivity and specificity) of AI-assisted cancer contours (84.7%) was superior to cognitively-defined (67.2%) and hemigland contours (75.9%; P < .0001). Cognitively-defined cancer contours systematically underestimated cancer extent, with a negative margin rate of 1.6% compared to 72.8% for AI-assisted cancer contours (P < .0001).

CONCLUSIONS

AI-assisted cancer contours reduce underestimation of prostate cancer extent, significantly improving contouring accuracy and negative margin rate achieved by physicians. This technology can potentially improve outcomes, as accurate contouring informs patient management strategy and underpins the oncologic efficacy of treatment.

Prediction and Mapping of Intraprostatic Tumor Extent with Artificial Intelligence

Background

Magnetic resonance imaging (MRI) underestimation of prostate cancer extent complicates the definition of focal treatment margins.

Objective

To validate focal treatment margins produced by an artificial intelligence (AI) model.

Design setting and participants

Testing was conducted retrospectively in an independent dataset of 50 consecutive patients who had radical prostatectomy for intermediate-risk cancer. An AI deep learning model incorporated multimodal imaging and biopsy data to produce three-dimensional cancer estimation maps and margins. AI margins were compared with conventional MRI regions of interest (ROIs), 10-mm margins around ROIs, and hemigland margins. The AI model also furnished predictions of negative surgical margin probability, which were assessed for accuracy.

Outcome measurements and statistical analysis

Comparing AI with conventional margins, sensitivity was evaluated using Wilcoxon signed-rank tests and negative margin rates using chi-square tests. Predicted versus observed negative margin probability was assessed using linear regression. Clinically significant prostate cancer (International Society of Urological Pathology grade ≥2) delineated on whole-mount histopathology served as ground truth.

Results and limitations

The mean sensitivity for cancer-bearing voxels was higher for AI margins (97%) than for conventional ROIs (37%, p < 0.001), 10-mm ROI margins (93%, p = 0.24), and hemigland margins (94%, p < 0.001). For index lesions, AI margins were more often negative (90%) than conventional ROIs (0%, p < 0.001), 10-mm ROI margins (82%, p = 0.24), and hemigland margins (66%, p = 0.004). Predicted and observed negative margin probabilities were strongly correlated (R2 = 0.98, median error = 4%). Limitations include a validation dataset derived from a single institution's prostatectomy population.

Conclusions

The AI model was accurate and effective in an independent test set. This approach could improve and standardize treatment margin definition, potentially reducing cancer recurrence rates. Furthermore, an accurate assessment of negative margin probability could facilitate informed decision-making for patients and physicians.

Patient summary

Artificial intelligence was used to predict the extent of tumors in surgically removed prostate specimens. It predicted tumor margins more accurately than conventional methods.

Intermediate Grade Prostate Cancer and Risk for Adverse Pathology Radical Prostatectomy: Implications for Partial Gland Ablation Case Selection

PURPOSE

Using nationally representative data, we determined the likelihood of adverse pathology at radical prostatectomy (RP) to better inform case selection for partial gland ablation (PGA).

MATERIALS AND METHODS

We identified men with clinically localized GG2 (n = 106,048) and GG3 (n = 55,488) prostate cancer on biopsy from 2010 through 2019 who subsequently underwent RP. Men with GG2 were stratified as unfavorable and favorable per NCCN guidelines. RP adverse pathology was defined as upgrading to GG4-5, pT3-4, or nodal involvement (pN1), respectively. Logistic regression determined factors associated with adverse pathology, and the Cochran-Armitage Test was used to evaluate temporal trends.

RESULTS

Men with biopsy GG3 vs. GG2 experienced significant upgrading (11.3% vs. 3.6%, P < .001), more EPE (26.9% vs. 21.1%), SVI (11.9% vs. 5.3%), and pN1 (4.3% vs. 1.6%), all P < .001. When comparing unfavorable vs. favorable GG2, men experienced more EPE (25.3% vs. 16.5%), SVI (7.2% vs. 3%), and pN1 (2.2% vs. 0.8%), all P < .001. In adjusted analysis, age, Hispanic race, PSA > 10 ng/mL, and ≥ 50% positive biopsy cores were associated with adverse pathology (all P < .001). The likelihood of RP adverse pathology for men with biopsy GG3 increased significantly during the study period from 38.8% in 2010 to 47.3% in 2019 (P < .001).

CONCLUSION

Approximately 40% of men with GG3 and more than 30% with unfavorable GG2 prostate cancer harbor adverse pathology that may not be curable by PGA. Given MRI often understages prostate cancer, our findings have significant implications for optimizing PGA case selection and cancer control outcomes.

Ipsilateral hemigland prostate biopsy may underestimate cancer burden in patients with unilateral mpMRI-visible lesions

PURPOSE

To evaluate the cancer detection rates of reduced-core biopsy schemes in patients with unilateral mpMRI-visible intraprostatic lesions and to analyze the contribution of systematic biopsy cores in clinically significant prostate cancer (csPCa) detection.

METHODS

212 patients with mpMRI-visible unilateral intraprostatic lesions undergoing MRI/TRUS fusion-guided targeted biopsy (TBx) and systematic biopsy (SBx) were included. Cancer detection rates of TBx + SBx, as determined by highest Gleason Grade Group (GG), were compared to 3 reduced-core biopsy schemes: TBx alone, TBx + ipsilateral systematic biopsy (IBx; MRI-positive hemigland), and TBx + contralateral systematic biopsy (CBx; MRI-negative hemigland). Patient-level and biopsy core-level data were analyzed using descriptive statistics with confidence intervals. Univariable and multivariable logistic regression analysis was conducted to identify predictors of csPCa (≥ GG2) detected in MRI-negative hemiglands at p < 0.05.

RESULTS

Overall, 43.4% (92/212) of patients had csPCa and 66.0% (140/212) of patients had any PCa detected by TBx + SBx. Of patients with csPCa, 81.5% had exclusively ipsilateral involvement (MRI-positive), 7.6% had only contralateral involvement (MRI-negative), and 10.9% had bilateral involvement. The csPCa detection rates of reduced-core biopsy schemes were 35.4% (75/212), 40.1% (85/212), and 39.6% (84/212) for TBx alone, TBx + IBx, and TBx + CBx, respectively, with detection sensitivities of 81.5%, 92.4%, and 91.3% compared to TBx + SBx.

CONCLUSION

Reduced-core prostate biopsy strategies confined to the ipsilateral hemigland underestimate csPCa burden by at least 8% in patients with unilateral mpMRI-visible intraprostatic lesions. The combined TBx + SBx strategy maximizes csPCa detection.

Value of magnetic resonance imaging/ultrasound fusion prostate biopsy to select patients for focal therapy

PURPOSE

To investigate the role of transrectal MRI fusion biopsy to select patients for prostate cancer focal therapy.

METHODS

Patients with suspected prostate cancer underwent transrectal MRI fusion biopsy with the Koelis trinity device. Two focal therapy eligibility criteria were subsequently defined: Group 1: PSA ≤ 15 ng/ml, unilateral csPCa, ISUP grade ≤ 2, no contralateral PIRADS 3-5 lesion; Group 2: same criteria but ISUP grade 3. These subgroups were correlated with histopathological post-prostatectomy parameters for stage pT2, unilateral csPCa, no ISUP upgrading. In addition, parameters of csPCa detection were analyzed for patients undergoing primary and re-biopsy.

RESULTS

Four hundred fourteen consecutive patients were analyzed (314 for primary biopsy, 100 for re-biopsy). Post-prostatectomy whole mount section analysis was available from 155 patients. 39 and 62 of these patients met focal therapy inclusion criteria for group 1 and group 2, respectively. A correlation with final pathology parameters following radical prostatectomy (stage pT2, unilateral csPCa, no ISUP upgrading) revealed a positive predictive value of only 53.8% and 64.5% for Group 1 and 2, respectively. The overall csPCa detection rate was 73.7%. In the re-biopsy group 20% additional patients with csPCa were detected by targeted biopsy.

CONCLUSION

Despite high csPCa detection rates following MRI fusion biopsy our study demonstrated that, using final pathology to confirm locally advanced tumor stage, presence of bilateral csPCa and ISUP upgrading, between 35.5 and 46.2% of patients would have been incorrectly selected for focal therapy.

The benefit of adopting Microultrasound in the prostate cancer imaging pathway: A lesion-by-lesion analysis: Biopsies prostatiques guidée par micro-échographie, quel bénéfice ? Une analyse lésion par lésion

INTRODUCTION

- Microultrasound (MicroUS) is a novel imaging modality relying on a high-frequency transducer which confers a three-fold improvement in spatial resolution as compared with conventional transrectal ultrasound. We evaluated the diagnostic value of MRI-MicroUS fusion biopsy and determined the additional benefit of employing MicroUS.

METHODS

- Retrospective analysis of consecutive treatment-naïve men undergoing MRI-MicroUS fusion biopsy between May 2018 and March 2019. Pre-biopsy MRI was systematically reviewed in a dedicated meeting where suspicious lesions PIRADS ≥ 3 were registered and uploaded in the ExactVu MicroUS device. MRI and MicroUS lesions were individually marked in a PIRADS v2 scheme. The biopsy protocol included MRI-MicroUS fusion and MicroUS targeted biopsies; systematic biopsies were performed at clinician's discretion. The diagnostic value was evaluated in terms of detection rate of clinically significant prostate cancer, defined as Gleason pattern ≥ 4 at histology.

RESULTS

- In all, 148 patients with a median age of 69 years (IQR 63-74) and median PSA density of 0.16 ng/ml/cc (0.10-0.23) were included. Clinically significant cancer was detected in 42.5% (63/148) patients. MRI detected 89 lesions in the peripheral zone; 73% (65/89) were visible on MicroUS. Clinically significant cancer was detected in 46.1% (30/65) MRI and MicroUS visible lesions, and in 4.2% (1/24) lesions only visible on mpMRI. MicroUS additionally identified 35 suspicious lesions non-visible on MRI of which clinically significant cancer was present in 25.7% (9/35).

CONCLUSION

- Adding MicroUS to the conventional pathway seems to increase the detection rate of clinically significant disease in unselected men undergoing biopsy. © 2022 Elsevier Masson SAS. All rights reserved.

Head-to-Head Comparison of 68Ga-PSMA-11 PET/CT and mpMRI with a Histopathology Gold Standard in the Detection, Intraprostatic Localization, and Determination of Local Extension of Primary Prostate Cancer: Results from a Prospective Single-Center Imaging Trial

The role of prostate-specific membrane antigen (PSMA)-targeted PET in comparison to multiparametric MRI (mpMRI) in the evaluation of intraprostatic cancer foci is not well defined. The aim of our study was to compare the diagnostic performance of ⁶⁸Ga-PSMA-11 PET/CT (PSMA PET/CT), mpMRI, and PSMA PET/CT + mpMRI using 3 independent masked readers for each modality and with histopathology as the gold standard in the detection, intraprostatic localization, and determination of local extension of primary prostate cancer. Methods: Patients with intermediate- or high-risk prostate cancer who underwent PSMA PET/CT as part of a prospective trial (NCT03368547) and mpMRI before radical prostatectomy were included. Each imaging modality was interpreted by 3 independent readers who were unaware of the other modality result. A central majority rule was applied (2:1). Pathologic examination of whole-mount slices was used as the gold standard. Imaging scans and whole-mount slices were interpreted using the same standardized approach on a segment level and a lesion level. A "neighboring" approach was used to define imaging-pathology correlation for the detection of individual prostate cancer foci. Accuracy in determining the location, extraprostatic extension (EPE), and seminal vesicle invasion (SVI) of prostate cancer foci was assessed using receiver-operating-characteristic curve analysis. Interreader agreement was calculated using intraclass correlation coefficient analysis. Results: The final analysis included 74 patients (14 [19%] with intermediate risk and 60 [81%] with high risk). The cancer detection rate (lesion-based analysis) was 85%, 83%, and 87% for PSMA PET/CT, mpMRI, and PSMA PET/CT + mpMRI, respectively. The change in AUC was statistically significant between PSMA PET/CT + mpMRI and the 2 imaging modalities alone for delineation of tumor localization (segment-based analysis) (P < 0.001) but not between PSMA PET/CT and mpMRI (P = 0.093). mpMRI outperformed PSMA PET/CT in detecting EPE (P = 0.002) and SVI (P = 0.001). In the segment-level analysis, intraclass correlation coefficient analysis showed moderate reliability among PSMA PET/CT and mpMRI readers using a 5-point Likert scale (range, 0.53-0.64). In the evaluation of T staging, poor reliability was found among PSMA PET/CT readers and poor to moderate reliability was found for mpMRI readers. Conclusion: PSMA PET/CT and mpMRI have similar accuracy in the detection and intraprostatic localization of prostate cancer foci. mpMRI performs better in identifying EPE and SVI. For the T-staging evaluation of intermediate to high-risk prostate cancer, mpMRI should still be considered the imaging modality of reference. Whenever available, PSMA PET/MRI or the coregistration or fusion of PSMA PET/CT and mpMRI (PSMA PET/CT + mpMRI) should be used as it improves tumor extent delineation.

Electroporation-based proteome sampling ex vivo enables the detection of brain melanoma protein signatures in a location proximate to visible tumor margins

A major concern in tissue biopsies with a needle is missing the most lethal clone of a tumor, leading to a false negative result. This concern is well justified, since needle-based biopsies gather tissue information limited to needle size. In this work, we show that molecular harvesting with electroporation, e-biopsy, could increase the sampled tissue volume in comparison to tissue sampling by a needle alone. Suggested by numerical models of electric fields distribution, the increased sampled volume is achieved by electroporation-driven permeabilization of cellular membranes in the tissue around the sampling needle. We show that proteomic profiles, sampled by e-biopsy from the brain tissue, ex vivo, at 0.5mm distance outside the visible margins of mice brain melanoma metastasis, have protein patterns similar to melanoma tumor center and different from the healthy brain tissue. In addition, we show that e-biopsy probed proteome signature differentiates between melanoma tumor center and healthy brain in mice. This study suggests that e-biopsy could provide a novel tool for a minimally invasive sampling of molecules in tissue in larger volumes than achieved with traditional needle biopsies.

WITHDRAWN: The benefit of adopting Microultrasound in the prostate cancer imaging pathway : A lesion-by-lesion analysis

INTRODUCTION

Microultrasound (MicroUS) is a novel imaging modality relying on a high-frequency transducer which confers a three-fold improvement in spatial resolution as compared with conventional transrectal ultrasound. We evaluated the diagnostic value of MRI-MicroUS fusion biopsy and determined the additional benefit of employing MicroUS.

METHODS

Retrospective analysis of consecutive treatment-naïve men undergoing MRI-MicroUS fusion biopsy between May 2018 and March 2019. Pre-biopsy MRI was systematically reviewed in a dedicated meeting where suspicious lesions PIRADS≥3 were registered and uploaded in the ExactVu MicroUS device. MRI and MicroUS lesions were individually marked in a PIRADS v2 scheme. The biopsy protocol included MRI-MicroUS fusion and MicroUS targeted biopsies; systematic biopsies were performed at clinician's discretion. The diagnostic value was evaluated in terms of detection rate of clinically significant prostate cancer, defined as Gleason pattern≥4 at histology.

RESULTS

In all, 148 patients with a median age of 69 years (IQR 63-74) and median PSA density of 0.16ng/ml/cc (0.10-0.23) were included. Clinically significant cancer was detected in 42.5% (63/148) patients. MRI detected 89 lesions in the peripheral zone; 73% (65/89) were visible on MicroUS. Clinically significant cancer was detected in 46.1% (30/65) MRI and MicroUS visible lesions, and in 4.2% (1/24) lesions only visible on mpMRI. MicroUS additionally identified 35 suspicious lesions non-visible on MRI of which clinically significant cancer was present in 25.7% (9/35).

CONCLUSION

Adding MicroUS to the conventional pathway seems to increase the detection rate of clinically significant disease in unselected men undergoing biopsy.

Transperineal prostate biopsy identifies locations of clinically significant prostate cancer in men considering focal therapy with PI‐RADS 3–5 regions of interest

Objectives

To determine the benefit of performing transperineal prostate mapping biopsy (TPMB) following multiparametric magnetic resonance imaging (mpMRI) to increase the identification of clinically significant prostate cancer (csPCa) with Gleason grade group (GG) ≥ 2 and their locations outside of the PI‐RADS v2 3–5 category lesions.

Methods

mpMRI was performed in 80 men prior TPMB from two institutions. The mpMRI was considered clinically significant (csMRI) if it contained one or more PI‐RADS 3–5 category lesion. mpMRI findings were compared against csPCa diagnosed by TPMB, performed between 16 November 2010, and 13 September 2019, for the entire gland, both lobes and to the right and left anterior and right and left posterior quadrants (RA, LA, RP and LP). Sensitivity, specificity, positive and negative predictive values (PPV, NPV), accuracy and the area under curve (AUC) were determined. Thirteen men also underwent radical prostatectomy and had comparison of TPMB pathology to prostatectomy specimen grading.

Results

TPMB was positive in 60/80 (75%) of which 32 (53.3%) were csPCa. csPCa was present in the RA in 9 (11.3%), LA in 11 (13.8%), RP in 25 (31.3%) and LP in 27 (33.8%) and involved 1 quadrant in 7 (21.9%), 2 quadrants in 12 (37.5%), 3 quadrants in 11 (34.4%) and all 4 quadrants in 2 (6.3%) patients; 57/80 (71.3%) men had a mpMRIs with lesions designated as PI‐RADS 3 in 24 (30%), 4 in 25 (31.3%) and 5 in 8 (10%). A csMRI was present in the RA in 7 (8.8%), LA in 8 (10%), RP in 31 (38.8%) and in the LP in 29 (36.3%), which were limited to one quadrant in 39 (68.4%), 2 quadrants in 16 (28.1%), and 3 quadrants in 2 (3.5%). Sensitivity, specificity, PPV, and NPV were determined from the results of the TPMB and were for the entire gland 81.3%, 35.4%, 45.6% and 73.9%. There were 31 csMRIs involving the right posterior of the gland but only 25 csPCa by TPMB of which 12/31 (38.7%) were concordant for high grade disease. There were 29 men who have a csMRI in the left posterior quadrant, and 14 (48.3%) were concordant with csPCa from the TPMB.

Conclusions

MpMRI should be supplemented with TPMB to correctly identify the regions of the prostate that would require ablation in men considering focal therapy.

[High-intensity focused ultrasound for locally prostate cancer: An Afro-Caribbean single-center study]

INTRODUCTION

High-intensity focused ultrasound (HIFU) has proved to be effective in the treatment of localized prostate cancer. The aim of this prospective study is to assess their first oncological and functional results in an Afro-Caribbean population.

METHODS

From May 2018 to January 2020, 77 patients issued from French West Indies were included. Several treatments were carried out: whole-gland treatment hemi or focal ablation; in a primary setting (group I) or a salvage therapy (group II). PSA level was assessed at 2, 6, 9 and 12 months. MpMRI and post HIFU biopsy were performed between 6 and 9 months postoperatively. Continence, urinary end erectile functions were assessed by ICS, IPSS and IIEF scores.

RESULTS

Groupe I included 71.2% patients, group II, 28.8%. The median age was 75.4 years [IQR 69.6-79.4]. The median follow-up was 8.3 months [IQR 3.5-12.25]. At inclusion, PSA was 7.7ng/ml [IQR 5.5-11.2] in group I, and 5.9ng/ml [IQR 4.4-7.9] in group II. In the whole population, there was 73.5% negative biopsies; 14.7% of the biopsies were positive in treated zone and 11.8% in non-treated zone. Regarding morbidities, urinary incontinence appeared in 7.5% and erectile dysfunction rate was 13.2%.

CONCLUSION

Our study reveals the first experience of HIFU by Focal One® device in an Afro-Caribbean population. It seems to be a safe and reproducible treatment with acceptable oncological results and low genitourinary morbidity. Long term follow-up and a higher number of patients are necessary to validate these results.

Acceptance, Indications and Chances of Focal Therapy in Localized Prostate Cancer: A Real-World Perspective of Urologists in Germany

Purpose: Focal therapy (FT) became a frequently discussed treatment strategy of localized prostate cancer (PCa), but the acceptance and evaluation of FT by practicing urologists are still unclear. Methods: A 25-item anonymized online questionnaire (SurveyMonkey^®) was compiled by the German Society of Residents in Urology Academics Prostate Cancer Working Group and sent to the members of the German association of Urology. Logistic regression analysis was performed to determine parameters for suggestion FT. Results: Two hundred ten urologists (median age 49 years) participated, from which 72% stated PCa as their main treatment focus. Ninety-nine percent of urologists were aware of and 54% wanted to improve their knowledge about FT. Sixty-five percent do not treat PCa with FT. FT is seen as an alternative to active surveillance and radiotherapy/radical prostatectomy by 66% and 37%, respectively. Regarding FT treatment strategies, 35% and 45% would treat all or all significant PCa foci, respectively, whereas 19% would treat mainly the index foci. Currently, 27% believe that FT will be an option as standard treatment in future, but 48% would not suggest FT to their patients, owing to an absence of evidence and insufficient diagnostic tools for proper patient selection today. Suggesting FT to patients is associated with self-performing FT (odds ratio [OR] 2.88, 95% confidence interval [CI] 1.31-6.31) and believing in FT as a standard treatment in future (OR 9.05, 95% CI 6.68-22.30) (both p < 0.01). Conclusion: FT has currently no wide acceptance in German practicing urologists, mainly attributable to an absence of evidence for FT superiority compared to standard treatments.

Focal therapy, time to join the multi-disciplinary team discussion?

Organ preserving management is common place in renal cancer, breast cancer and many other solid organ tumours. Current strategies in managing intermediate risk prostate cancer include either whole gland treatment, in the form of radical radiotherapy or radical prostatectomy, or active surveillance. The former is associated with significant post-treatment functional morbidity, whilst the latter associated with the burden of surveillance activity and patient anxiety. Focal therapy would logically fit as a middle ground for suitable patients in whom treatment would be recommended, but where much better functional outcomes may be possible. Ideally this comes without restricting the successful prevention of harm from the cancer. Historically limitations in developing tissue preserving focal therapy strategies in prostate cancer, were due to inaccuracies in tumour characterisation prior to treatment and during follow up. Consequently for example many patients undergoing an active surveillance strategy were being upgraded and upstaged within a short period. Recently high level evidence supporting the use of MRI and targeted biopsies, in particular the PROMIS and PRECISION trials have strengthened clinician confidence in accurate disease characterisation, thus making focal therapy to become a more feasible management option. With improved diagnostic strategies and the publication of reassuring medium term oncological and functional outcomes after focal therapy for intermediate risk prostate cancer, has the time come to require consideration of focal therapy within our multi-disciplinary team (MDT) meetings and with patients? In this review we will consider patient selection and the evidence for the various focal ablation options as well as the surveillance of these patients after treatment. The forthcoming trials to determine comparative effectiveness will be discussed.

Making a case "against" focal therapy for intermediate-risk prostate cancer

INTRODUCTION

Focal therapy (FT) for localized prostate cancer (PCa) is a promising treatment strategy. Although, according to guidelines, it should be regarded as an experimental option, its introduction into clinical practice has occurred at an accelerated speed. It is, thus, crucial for Urologists to understand FT limitations and potential drawbacks that may derive from its use.

METHODS

We performed a literature search of peer-reviewed English language articles using Pubmed and the words "focal therapy" AND "prostate cancer" to identify relevant articles. Web search was complemented by manual search.

RESULTS

From a biological perspective, in contrast with the index lesion theory, which still needs to be better supported, PCa is a multifocal and multiclonal entity. Also, the effects of FT on PCa microenvironment are unclear. From a clinical perspective, patient selection is still not precisely defined. Even when all variables potentially decreasing mpMRI and biopsy accuracy are optimized, up to one out of two men may be incorrectly selected for FT, leaving a significant proportion of clinically significant PCa (csPCa) untreated. Underestimation of PCa volume and variant histologies are other additional mpMRI potential limitations. No RCTs have been performed against the standard of care to support FT. There is absence of long-term results and FT series reaching medium-term follow-up have non-optimal oncological control with significant re-treatment needs. When PCa recurs/persists after FT, little is known about the appropriate management strategies and their outcomes. Finally, the optimal follow-up scheme post-FT remains unclear.

CONCLUSIONS

Several arguments are present against the use of FT for localized PCa. Studies are needed to overcome current limitations and support FT before it can be included as part of the standard management of prostate cancer.

Prostate cancer screening research can benefit from network medicine: an emerging awareness

Up to date, screening for prostate cancer (PCa) remains one of the most appealing but also a very controversial topics in the urological community. PCa is the second most common cancer in men worldwide and it is universally acknowledged as a complex disease, with a multi-factorial etiology. The pathway of PCa diagnosis has changed dramatically in the last few years, with the multiparametric magnetic resonance (mpMRI) playing a starring role with the introduction of the “MRI Pathway”. In this scenario the basic tenet of network medicine (NM) that sees the disease as perturbation of a network of interconnected molecules and pathways, seems to fit perfectly with the challenges that PCa early detection must face to advance towards a more reliable technique. Integration of tests on body fluids, tissue samples, grading/staging classification, physiological parameters, MR multiparametric imaging and molecular profiling technologies must be integrated in a broader vision of “disease” and its complexity with a focus on early signs. PCa screening research can greatly benefit from NM vision since it provides a sound interpretation of data and a common language, facilitating exchange of ideas between clinicians and data analysts for exploring new research pathways in a rational, highly reliable, and reproducible way.

Using spatial tracking with magnetic resonance imaging/ultrasound-guided biopsy to identify unilateral prostate cancer

OBJECTIVES

To create reliable predictive metrics of unilateral disease using spatial tracking from a fusion device, thereby improving patient selection for hemi-gland ablation of prostate cancer.

PATIENTS AND METHODS

We identified patients who received magnetic resonance imaging (MRI)/ultrasound-guided biopsy and radical prostatectomy at a single institution between 2011 and 2018. In addition to standard clinical features, we extracted quantitative features related to biopsy core and MRI target locations predictive of tumour unilaterality. Classification and Regression Tree (CART) analysis was used to create a decision tree (DT) for identifying cancer laterality. We evaluated concordance of model-determined laterality with final surgical pathology.

RESULTS

A total of 173 patients were identified with biopsy coordinates and surgical pathology available. Based on CART analysis, in addition to biopsy- and MRI-confirmed disease unilaterality, patients should be further screened for cancer detected within 7 mm of midline in a 40 mL prostate, which equates to the central third of any-sized prostate by radius. The area under the curve for this DT was 0.82. Standard diagnostics and the DT correctly identified disease laterality in 73% and 80% of patients, respectively (P = 0.13). Of the patients identified as unilateral by standard diagnostics, 47% had undetected contralateral disease or were otherwise incorrectly identified. This error rate was reduced to 17% (P = 0.01) with the DT.

CONCLUSION

Using spatial tracking from fusion devices, a DT was more reliable for identifying laterality of prostate cancer compared to standard diagnostics. Patients with cancer detected within the central third of the prostate by radius are poor hemi-gland ablation candidates due to the risk of midline extension of tumour.