Combination of multiparametric magnetic resonance imaging and transrectal ultrasound-guided prostate biopsies is not enough for identifying patients eligible for hemiablative focal therapy for prostate cancer

Predictors of Contralateral Disease in Men with Unilateral Lesions on Multiparametric MRI

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 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. (Figure 1). Prior negative biopsy (OR 0.34 [0.14, 0.75], p = 0.012), PSA density (OR 18.8 [2.77, 249], p = 0.017), and tumor location in the transverse plane ("Posterior": OR 1.93 [1.02, 3.87], p =0.048; "Throughout Transverse Plane": OR 6.56 [2.26, 19.6], p <0.001) 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).

CONCLUSIONS

Approximately 20% of men with unilateral MRI findings and csPCa on targeted-biopsy were found to have contralateral csPCa. Prior negative biopsy was associated with a decreased odds of contralateral csPCa. PSA 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.

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.

Accuracy of elastic fusion biopsy: Comparing prostate cancer detection between targeted and systematic biopsy

INTRODUCTION

When performing targeted biopsy (TBx), the need to add systematic biopsies (SBx) is often debated. Aim of the study is to evaluate the added value of SBx in addition to TBx in terms of prostate cancer (PCa) detection rates (CDR), and to test the concordance between multiparametric magnetic resonance imaging (mpMRI) findings and fusion biopsy results in terms of cancer location.

METHODS

We performed a retrospective, multicentric study that gathered data on 1992 consecutive patients who underwent elastic fusion biopsy between 2011 and 2020. A standardized approach was used, with TBx (2-4 cores per target) followed by SBx (12-14 cores). We assessed CDR of TBx, of SBx, and TBx+SBx for all cancers and clinically significant PCa (csPCa), defined as ISUP score ≥2. CDR was evaluated according to radiological and clinical parameters, with a particular focus on PI-RADS 3 lesions. In a subgroup of 1254 patients we tested the discordance between mpMRI findings and fusion biopsy results in terms of cancer location. Uni- and multivariable logistic regression analyses were performed to identify predictors of CDR.

RESULTS

CDR of TBx+SBx was 63.0% for all cancers and 38.8% of csPCa. Per-patient analysis showed that SBx in addition to TBx improved CDR by 4.5% for all cancers and 3.4% for csPCa. Patients with lesions scored as PI-RADS 3, 4, and 5 were diagnosed with PCa in 27.9%, 72.8%, and 92.3%, and csPCa in 10.7%, 43.6%, and 69.3%, respectively. When positive, PI-RADS 3 lesions were ISUP grade 1 in 61.1% of cases. Per-lesion analysis showed that discordance between mpMRI and biopsy was found in 56.6% of cases, with 710 patients having positive SBx outside mpMRI targets, of which 414 (58.0%) were clinically significant. PSA density ≥0.15 was a strong predictor of CDR.

CONCLUSIONS

The addition of systematic mapping to TBx contributes to a minority of per-patient diagnoses but detects a high number of PCa foci outside mpMRI targets, increasing biopsy accuracy for the assessment of cancer burden within the prostate. High PSA-density significantly increases the risk of PCa, both in the whole cohort and in PI-RADS 3 cases.

Intraoperative 3D-US-mpMRI Elastic Fusion Imaging-Guided Robotic Radical Prostatectomy: A Pilot Study

INTRODUCTION

When performing a nerve-sparing (NS) robotic radical prostatectomy (RARP), cancer location based on multiparametric MRI (mpMRI) is essential, as well as the location of positive biopsy cores outside mpMRI targets. The aim of this pilot study was to assess the feasibility of intraoperative 3D-TRUS-mpMRI elastic fusion imaging to guide RARP and to evaluate its impact on the surgical strategy.

METHODS

We prospectively enrolled 11 patients with organ-confined mpMRI-visible prostate cancer (PCa), histologically confirmed at transperineal fusion biopsy using Koelis Trinity. Before surgery, the 3D model of the prostate generated at biopsy was updated, showing both mpMRI lesions and positive biopsy cores, and was displayed on the Da Vinci robotic console using TilePro™ function.

RESULTS

Intraoperative 3D modeling was feasible in all patients (median of 6 min). The use of 3D models led to a major change in surgical strategy in six cases (54%), allowing bilateral instead of monolateral NS, or monolateral NS instead of non-NS, to be performed. At pathologic examination, no positive surgical margins (PSMs) were reported. Bilateral PCa presence was detected in one (9%), four (36%), and nine (81%) patients after mpMRI, biopsy, and RARP, respectively. Extracapsular extension was found in two patients (18%) even if it was not suspected at MRI.

CONCLUSIONS

Intraoperative 3D-TRUS-mpMRI modeling with Koelis Trinity is feasible and reliable, helping the surgeon to maximize functional outcomes without increasing the risk of positive surgical margins. The location of positive biopsy cores must be registered in 3D models, given the rates of bilateral involvement not seen at mpMRI.

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.

Multifocality of Prostate Cancer and Candidacy for Focal Therapy Based on Magnetic Resonance Imaging

OBJECTIVES

To determine the prevalence of multiparametric magnetic resonance imaging (mpMRI)-detected and targeted biopsy-confirmed multifocal and unifocal prostate cancer (PCa) among patients with Prostate Imaging Reporting and Data System (PI-RADS) ≥3 lesions. Focal therapy (FT) options for PCa are tied to accurate spatial identification on mpMRI.

METHODS

Men without prior diagnosis of PCa receiving mpMRI, targeted and systematic prostate biopsy in the Prospective Loyola Urology mpMRI (PLUM) Prostate Biopsy Cohort from 2015-2021 were included. Patients with PI-RADS ≥3 lesions were classified by mpMRI lesion location, targeted biopsy, and systematic biopsy. Patients with single biopsy-confirmed grade group (GG) 2 lesions and concordant systematic biopsy were defined as FT candidates. Multivariable logistic regression evaluated predictors of mpMRI-undetected contralateral PCa.

RESULTS

Of 897 patients, 450 (50.2%) had a single, 141 (15.7%) had multiple unilateral, and 306 (34.1%) had bilateral mpMRI lesions. 28.7% had a single targeted biopsy-confirmed lesion while 10.4% were multifocal. Among single targeted biopsy-confirmed patients, 92/257 (35.8%) had contralateral PCa missed by mpMRI with DRE, PSA, and biopsy history identified as independent predictors. Systematic biopsy findings dropped the rate of single confirmed lesions from 28.7% to 18.4% and multifocal PCa increased from 10.4% to 20.6%. After GG restrictions, 61/897 (6.8%) remained potential FT candidates.

CONCLUSIONS

Among men with clinical suspicion of prostate cancer receiving mpMRI, 28.7% had a single targeted biopsy-confirmed lesion and 10.4% had multifocality on mpMRI, but many mpMRI-undetected contralateral PCa were identified. Only 6.0% of biopsy-naïve men remained with a single GG2 mpMRI lesion potentially amenable to FT.

Detection of prostate cancer using prostate imaging reporting and data system score and prostate-specific antigen density in biopsy-naive and prior biopsy-negative patients

Background

Few studies report on indications for prostate biopsy using Prostate Imaging–Reporting and Data System (PI-RADS) score and prostate-specific antigen density (PSAD). No study to date has included biopsy-naïve and prior biopsy-negative patients. Therefore, we evaluated the predictive values of the PI-RADS, version 2 (v2) score combined with PSAD to decrease unnecessary biopsies in biopsy-naïve and prior biopsy-negative patients.

Materials and methods

A total of 1,098 patients who underwent multiparametric magnetic resonance imaging at our hospital before a prostate biopsy and who underwent their second prostate biopsy with an initial benign negative prostatic biopsy were included. We found factors associated with clinically significant prostate cancer (csPca). We assessed negative predictive values by stratifying biopsy outcomes by prior biopsy history and PI-RADS score combined with PSAD.

Results

The median age was 65 years (interquartile range: 59-70), and the median PSA was 5.1 ng/mL (interquartile range: 3.8-7.1). Multivariate logistic regression analysis revealed that age, prostate volume, PSAD, and PI-RADS score were independent predictors of csPca. In a biopsy-naïve group, 4% with PI-RADS score 1 or 2 had csPca; in a prior biopsy-negative group, 3% with PI-RADS score 1 or 2 had csPca. The csPca detection rate was 2.0% for PSA density <0.15 ng/mL/mL and 4.0% for PSA density 0.15-0.3 ng/mL/mL among patients with PI-RADS score 3 in a biopsy-naïve group. The csPca detection rate was 1.8% for PSA density <0.15 ng/mL/mL and 0.15-0.3 ng/mL/mL among patients with PI-RADS score 3 in a prior biopsy-negative group.

Conclusion

Patients with PI-RADS v2 score ≤2, regardless of PSA density, may avoid unnecessary biopsy. Patients with PI-RADS score 3 may avoid unnecessary biopsy through PSA density 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.

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.

Targeted Biopsy With Reduced Number of Cores: Optimal Sampling Scheme in Patients Undergoing Magnetic Resonance Imaging/Transrectal Ultrasound Fusion Prostate Biopsy

The 3 Tesla (3T) magnetic resonance imaging (MRI) combined ultrasound (TRUS) targeted biopsy plus 12-core systematic biopsy (TBx + 12-SBx) was considered a reliable method for prostate cancer (PCa) diagnosis. To find another optimal sampling scheme with fewer cores and the same efficiency as TBx + 12-SBx for prostate biopsy, 113 patients who underwent five different hypothetical sampling schemes were analyzed and compared with TBx + 12-SBx. The detection rates of targeted biopsy plus 6-core lateral systematic biopsy (TBx + lateral 6-SBx) for PCa and clinically significant prostate cancer (csPCa) (99.1% and 96.4%, respectively) were higher than other schemes, and the area under the receiver operating characteristic curve of TBx + lateral 6-SBx for PCa and csPCa (0.991 and 0.990, respectively) were also significantly higher than other sampling schemes except TBx plus 6-core ipsilateral systematic biopsy (TBx + ipsilateral 6-SBx). Additionally, TBx + lateral 6-SBx had the lowest missed diagnosis rate. Thus, the TBx + lateral 6-SBx may be the optimal scheme for patients undergoing MRI/TRUS fusion prostate biopsy.

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.