The Role of Systematic and Targeted Biopsies in Light of Overlap on Magnetic Resonance Imaging Ultrasound Fusion Biopsy

Prostate Cancer Detection Rate of Transperineal Prostate Biopsy: Cognitive vs Software Fusion, A Multicenter Analysis

OBJECTIVE

To compare clinically significant prostate cancer detection with TP-TBx utilizing software vs cognitive fusion. It is established that MRI prior to prostate biopsy improves detection of clinically significant cancer (csPCa, Grade Group ≥2). MRI/US fusion targeted biopsy via a transperineal approach (TP-TBx) is increasing in utilization due to the clean percutaneous approach that greatly reduces postbiopsy infection. However, the comparative effectiveness of formal software fusion over cognitive fusion remains under studied.

MATERIALS AND METHODS

We performed a retrospective multicenter study from June 2020 to July 2022 including age, race, prostate-specific antigen (PSA), prostate volume, PI-RADS, lesion size(s), number of cores sampled, indication (elevated PSA, prior negative, active surveillance) and anesthesia type. Surgeon preference determined use of cognitive (PrecisionPoint) vs software fusion techniques. Multivariable logistic regression determined factors associated with TP-TBx detection of csPCa.

RESULTS

We identified 490 patients (201 cognitive, 289 software fusion) who underwent TP-TBx. Patient age, PSA, number of targets, and PI-RADS were similar (all P > .05). Software fusion TP-TBx had 4 [95% confidence interval (CI) 3-5] more (estimated median difference) systematic cores sampled. csPCa was detected in 44% of all patients. In adjusted analysis, cognitive vs software fusion was similar in detection of csPCa (odds ratio 1.46, 95% CI 0.82-2.58).

CONCLUSION

Cognitive vs software fusion TP-TBx has similar csPCa detection, despite fewer systematic cores taken with cognitive fusion. The expense, additional time requirement, and similar outcomes of software fusion platforms confers higher value to cognitive TP-Bx.

Cumulative cancer locations on prostate biopsy and active surveillance outcomes in the MRI era

BACKGROUND

To validate the use of a cumulative cancer locations (CCLO) score, a measurement of tumor volume on biopsy, and to develop a novel magnetic resonance imaging (MRI)-informed CCLO (mCCLO) score to predict clinical outcomes on active surveillance (AS).

METHODS

The CCLO score is a sum of uniquely involved sextants with prostate cancer on diagnostic + confirmatory biopsy. The mCCLO score incorporates MRI findings into the CCLO score. Participants included 1284 individuals enrolled on AS between 1994 and 2022, 343 of whom underwent prostate MRI. The primary outcome was grade reclassification (GR) to grade group ≥2 disease; the secondary outcome was receipt of definitive treatment.

RESULTS

Increasing CCLO and mCCLO risk groups were associated with higher risk of GR and undergoing definitive treatment (both p < 0.001). On multivariable analysis, increasing mCCLO score was associated with higher risk of GR and receipt of definitive treatment (hazard ratios [HRs] per 1-unit increase: 1.26 [95% confidence interval [CI]: 1.12-1.41] and 1.21 [95% CI: 1.07-1.36], respectively). The model using mCCLO score to predict GR (c-index: 0.671; 95% CI: 0.621-0.721) performed at least as well as models using the number of cores positive for cancer (0.664 [0.613-0.715]; p = 0.7) and the maximum percentage of cancer in a core (0.641 [0.585-0.696]; p = 0.14).

CONCLUSIONS

The CCLO score is a valid, objective metric to predict GR and receipt of treatment in a large AS cohort. The ability of the MRI-informed mCCLO to predict GR is on par with traditional metrics of tumor volume but is more descriptive and may benefit from greater reproducibility. The mCCLO score can be implemented as a shorthand, informative tool for counseling patients about whether to remain on AS.

Intensive sampling of the umbra and penumbra improves clinically significant prostate cancer detection and reduces risk of grade group upgrading at radical prostatectomy

PURPOSE

Our objective is to evaluate the clinically significant prostate cancer detection rate of overlapping and perilesional systematic biopsy cores and its impact on grade group (GG) concordance at prostatectomy.

MATERIALS AND METHODS

Biopsy maps of those undergoing MRI-targeted (TB) and systematic biopsy (SB) were reviewed to reclassify systematic cores. Perilesional (PL) cores were defined as adjacent cores within 10 mm of the target lesion ("penumbra") whilst overlap (OL) cores were defined as cores within the ROI itself ("umbra"). All other cores were designated as distant cores (DC). The incremental csPCa detection rate (GG ≥ 2) and the rate of GG upgrading on prostatectomy as OL, PL and DC sequentially added to TB were determined.

RESULTS

Out of the 398 patients included, the median number of OL and PL cores was 5 (IQR 4-7) and 5 (IQR 3-6) respectively. OL cores detected more csPCa than PL cores (31 vs 16%, p < 0.001). OL and PL cores improved the csPCa detection rate of TB from 34 to 39% (p < 0.001) and 37% (p = 0.001) respectively. TB+OL+PL had greater csPCa detection compared to just TB+OL (41 vs 39%, p = 0.016) and TB+PL (41 vs 37%, p < 0.001). Of the 104 patients who underwent prostatectomy, GG upgrading rate for TB+OL+PL was lower compared to TB (21 vs 36%, p < 0.001) and was not significantly different compared to TB+OL+PL+DC (21 vs 19%, p = 0.500).

CONCLUSION

A biopsy strategy incorporating both intensive sampling of the umbra and penumbra improved csPCa detection and reduced risk of GG upgrading at prostatectomy.

Partial-gland Cryoablation Outcomes for Localized Prostate Cancer in Patients with Magnetic Resonance Imaging (MRI)-visible and MRI-invisible Lesions

Background

Expert consensus recommends treatment of magnetic resonance imaging (MRI)-visible prostate cancer (PCa). Outcomes of partial-gland ablation (PGA) for MRI-invisible PCa remain unknown.

Objective

To compare recurrence-free survival, adverse events, and health-related quality of life (HRQoL) outcomes following cryoablation of MRI-visible vs invisible PCa.

Design setting and participants

We analyzed data for 75 men who underwent cryoablation therapy between January 2017 and January 2022. PCa identified on MRI-targeted and/or adjacent systematic biopsy cores was defined as MRI-visible, whereas PCa identified on systematic biopsy beyond the targeted zone was defined as MRI-invisible.

Outcome measurements and statistical analysis

The primary outcome was recurrence at 12 mo after PGA, defined as the presence of clinically significant PCa (grade group [GG] ≥2) on surveillance biopsy. Adverse events were captured using the Clavien-Dindo classification and HRQoL was captured using the Expanded Prostate Cancer Index-Clinical Practice (EPIC-CP) tool.

Results and limitations

Of the 58 men treated for MRI-visible and 17 treated for MRI-invisible lesions, 51 (88%) and 16 (94%), respectively, had at least one surveillance biopsy performed. There were no statistically significant differences in age, race, body mass index, biopsy GG, prostate-specific antigen, prostate volume, or treatment extent between the MRI-visible and MRI-invisible groups. Median follow-up was 44 mo (interquartile range 17-54) and did not significantly differ between the groups. The recurrence rate at 12 mo did not significantly differ between the groups (MRI-visible 39%, MRI-invisible 19%; p = 0.2), and log-rank survival analysis demonstrated no significant difference in recurrence-free survival (p = 0.15). Adverse event rates did not significantly differ (MRI-visible 29%, MRI-invisible 53%; p = 0.092); no man in the MRI-visible group had a Clavien-Dindo grade ≥III complication, while one subject in the MRI-invisible group had a Clavien-Dindo grade III complication. Median EPIC-CP urinary and sexual function scores were similar for the two groups at baseline and at 12 mo after PGA. Study limitations include the retrospective design and small sample size.

Conclusions

We observed similar cancer control, adverse event, and HRQoL outcomes for MRI-visible versus MRI-invisible PCa in the first comparison of partial-gland cryoablation. Longer follow-up and external validation of our findings are needed to inform patient selection for PGA for MRI-invisible PCa.

Patient summary

Patients with prostate cancer lesions that are not visible on magnetic resonance imaging (MRI) scans who undergo partial gland ablation may have similar treatment outcomes compared to patients with cancer lesions that are visible on MRI.

Biopsy-Integrated 3D Magnetic Resonance Imaging Modeling of Prostate Cancer and Its Application for Gleason Grade and Tumor Laterality Assessment

CONTEXT.—

Grade Group assessed using Gleason combined score and tumor extent is a main determinant for risk stratification and therapeutic planning of prostate cancer.

OBJECTIVE.—

To develop a 3-dimensional magnetic resonance imaging (MRI) model regarding Grade Group and tumor extent in collaboration with uroradiologists and uropathologists for optimal treatment planning for prostate cancer.

DESIGN.—

We studied the data from 83 patients with prostate cancer who underwent multiparametric MRI and subsequent MRI-transrectal ultrasound fusion biopsy and radical prostatectomy. A 3-dimensional MRI model was constructed by integrating topographic information of MRI-based segmented lesions, biopsy paths, and histopathologic information of biopsy specimens. The multiparametric MRI-integrated Grade Group and laterality were assessed by using the 3-dimensional MRI model and compared with the radical prostatectomy specimen.

RESULTS.—

The MRI-defined index tumor was concordant with radical prostatectomy in 94.7% (72 of 76) of cases. The multiparametric MRI-integrated Grade Group revealed the highest agreement (weighted κ, 0.545) and a significantly higher concordance rate (57.9%) than the targeted (47.8%, P = .008) and systematic (39.4%, P = .01) biopsies. The multiparametric MRI-integrated Grade Group showed significantly less downgrading rates than the combined biopsy (P = .001), without significant differences in upgrading rate (P = .06). The 3-dimensional multiparametric MRI model estimated tumor laterality in 66.2% (55 of 83) of cases, and contralateral clinically significant cancer was missed in 9.6% (8 of 83) of cases. The tumor length measured by multiparametric MRI best correlated with radical prostatectomy as compared with the biopsy-defined length.

CONCLUSIONS.—

The 3-dimensional model incorporating MRI and MRI-transrectal ultrasound fusion biopsy information easily recognized the spatial distribution of MRI-visible and MRI-nonvisible cancer and provided better Grade Group correlation with radical prostatectomy specimens but still requires validation.

Prostate biopsy in the era of MRI-targeting: towards a judicious use of additional systematic biopsy

OBJECTIVES

We aimed to develop and compare strategies that help optimize current prostate biopsy practice by identifying patients who may forgo concurrent systematic biopsy (SBx) in favor of MRI-targeted (TBx) alone.

METHODS

Retrospective study on 745 patients who underwent combined MRI-TBx plus SBx. Primary outcome was the upgrade to clinically significant prostate cancer (csPCa; grade group ≥ 2) on SBx versus MRI-TBx. Variables (age, previous biopsy status, Prostate Imaging Reporting and Data System (PI-RADS) score, index lesion size/location, number of lesions, PSA, PSA density, prostate volume) associated with the primary outcome were identified by logistic regression and used for biopsy strategies. Clinical utility was assessed by decision curve analysis (DCA).

RESULTS

SBx detected 47 (6%) additional men with csPCa. The risk of detecting csPCa uniquely on SBx was significantly lower in men with PI-RADS 5 (versus PI-RADS 3: OR 0.30, p = 0.03; versus PI-RADS 4: OR 0.33, p = 0.01), and previous negative biopsy (versus previous positive biopsy: OR 0.40, p = 0.007), and increased with age (per 10 years: OR 1.64, p = 0.016). No significant association was observed for other variables. DCA identified the following strategies as most useful: (a) avoid SBx in men with PI-RADS 5 and (b) additionally in those with previous negative biopsy, resulting in avoiding SBx in 201 (27%) and 429 (58%), while missing csPCa in 5 (1%) and 15 (2%) patients, respectively.

CONCLUSION

Not all men benefit equally from the combination of SBx and MRI-TBx. SBx avoidance in men with PI-RADS 5 and/or previous negative biopsy may reduce the risk of excess biopsies with a low risk of missing csPCa.

KEY POINTS

• In men undergoing MRI-targeted biopsy, the risk of detecting clinically significant prostate cancer (csPCa) only on additional systematic biopsy (SBx) decreased in men with PI-RADS 5, previous negative biopsy, and younger age. • Using these variables may help select men who could avoid the risk of excess SBx. • If missing csPCa in 5% was acceptable, forgoing SBx in men with PI-RADS 5 and/or previous negative biopsy enabled the highest net reduction in SBx.

Reducing the number of systematic biopsy cores in the era of MRI targeted biopsy-implications on clinically-significant prostate cancer detection and relevance to focal therapy planning

BACKGROUND

The optimal number of systematic biopsy cores in the era of multi-parametric MRI targeted biopsy remains unclear, especially on its impact of focal therapy planning. Our objective is to investigate the impact of reducing the number of systematic cores on prostate cancer detection in the era of MRI-US fusion targeted biopsy and as well as its relevance in template planning for focal therapy.

MATERIALS AND METHODS

A retrospective analysis of 398 consecutive men who underwent both systematic saturation (~24 cores) and MRI-US fusion targeted biopsy was performed. Four reduced-core systematic biopsy strategies (two-thirds, half, one-third and one-quarter systematic cores) were modelled and the detection rates of clinically-significant prostate cancer (csPCa defined as grade group ≥2) were compared to that of a full systematic biopsy using McNemar's test. Focal therapy treatment plans were made based on positive cores on combined (targeted and systematic) biopsy and the various reduced-cores strategies to compare the proportion who had a change in treatment plan.

RESULTS

csPCa was detected in 42% (168/398) of this patient cohort. Non-targeted systematic saturation biopsy had a 21% (83/398) csPCa detection rate. Our four strategies reduced the mean number of non-targeted systematic cores from 21.8 to 14.5, 10.9, 7.3 and 5.4 cores and their csPCa detection rates were significantly decreased to 16%, 13%, 9% and 8% respectively (all p < 0.05). Compared to the reduced-core strategies, a full systematic saturation biopsy resulted in change to the focal therapy treatment plan in 12% (2/3 cores), 19% (1/2 cores), 24% (1/3 cores) and 29% (1/4 cores) of the time (p = 0.0434).

CONCLUSIONS

Reducing the number of systematic biopsies when performing an MRI-targeted biopsy leads to reduced detection of csPCa and alter the treatment plans for focal therapy, possibly limiting its oncological efficacy.

In-Bore Versus Fusion MRI-Targeted Biopsy of PI-RADS Category 4 and 5 Lesions: A Retrospective Comparative Analysis Using Propensity Score Weighting

BACKGROUND. Few published studies have compared in-bore and fusion MRI-targeted prostate biopsy, and the available studies have had conflicting results. OBJECTIVE. The purpose of this study was to compare the target-specific cancer detection rate of in-bore prostate biopsy with that of fusion MRI-targeted biopsy. METHODS. The records of men who underwent in-bore or fusion MRI-targeted biopsy of PI-RADS category 4 or 5 lesions between August 2013 and September 2019 were retrospectively identified. PI-RADS version 2.1 assessment category, size, and location of each target were established by retrospective review by a single experienced radiologist. Patient history and target biopsy results were obtained by electronic medical record review. Only the first MRI-targeted biopsy of the dominant lesion was included for patients with repeated biopsies or multiple targets. In-bore and fusion biopsy were compared by propensity score weights and multivariable regression to adjust for imbalances in patient and target characteristics between biopsy techniques. The primary endpoint was target-specific prostate cancer detection rate. Secondary endpoints were detection rate after application of propensity score weighting for cancers in International Society of Urological Pathology (ISUP) grade group 2 (GG2) or higher and detection rate with the use of off-target systematic sampling results. RESULTS. The study sample included 286 men (in-bore biopsy, 191; fusion biopsy, 95). Compared with fusion biopsy, in-bore biopsy was associated with significantly greater likelihood of detection of any cancer (odds ratio, 2.28 [95% CI, 1.04-4.98]; p = .04) and nonsignificantly greater likelihood of detection of ISUP GG2 or higher cancer (odds ratio, 1.57 [95% CI, 0.88-2.79]; p = .12) in a target. When off-target sampling was included, in-bore biopsy and combined fusion and systematic biopsy were not different for detection of any cancer (odds ratio, 1.16 [95% CI, 0.54-2.45]; p = .71) or ISUP GG2 and higher cancer (odds ratio, 1.15 [95% CI, 0.66-2.01]; p = .62). CONCLUSION. In this retrospective study in which propensity score weighting was used, in-bore MRI-targeted prostate biopsy had a higher target-specific cancer detection rate than did fusion biopsy. CLINICAL IMPACT. Pending a larger prospective randomized multicenter comparison between in-bore and fusion biopsy, in-bore may be the preferred approach should performing only biopsy of a suspicious target, without concurrent systematic biopsy, be considered clinically appropriate.

Limitations of overlapping cores in systematic and MRI-US fusion biopsy

OBJECTIVES

To evaluate the clinically-significant prostate cancer (csCaP) detection rate of systematic (SBx) vs. targeted biopsy (TBx), after accounting for the overlapping systematic cores within the MRI regions of interest.

MATERIALS AND METHODS

We identified 398 consecutive men who underwent both transperineal systematic and targeted biopsy between January 2015 to January 2019. We reclassified overlapping systematic cores in the MRI regions of interest as target cores. The detection rates of SBx and TBx were compared using McNemar's test.

RESULTS

Detection rate of csCaP (grade group ≥2) was 42% (168/398). Median number of systematic and targeted cores were 23 (IQR 19-29) and 9 (IQR 6-12) respectively. A median of 3 (IQR 2-4) overlapping systematic cores were reclassified as targeted cores. After accounting for overlap, csPC detection rate on SBx decreased from 37% and 21% while the csCaP detection rate of TBx increased from 34% to 39% (both P < 0.001), with TBx having a better detection rate (39% vs. 21%, P < 0.001). A previous negative biopsy was associated with a lower risk of having csCaP on non-targeted SBx (OR 0.27, 95% CI: 0.12 - 0.58, P = 0.001). Only 5% (13/243) of those who had no cancer detected on TBx had csCaP on non-targeted SBx compared to 45% (70/155) of those who had csCaP on TBx (P< 0.001).

CONCLUSIONS

The utility of SBx in detecting csCaP decreases after accounting for overlap into the MRI region of interest, especially in men with a prior negative biopsy. Overlapping systematic cores improve the csCaP detection rate on TBx.

Transperineal systematic biopsies in addition to targeted biopsies are important in the detection of clinically significant prostate cancer

BACKGROUND

This study aimed to determine whether the addition of transperineal systematic biopsies (SB) to targeted biopsies (TB) improved clinically significant prostate cancer (csPC) detection rates without high increase in insignificant prostate cancer detection rates in an Australian population.

METHODS

In this retrospective review, a total of 254 patients who had a Prostate Imaging-Reporting and Data System score between 3 and 5, and a transperineal TB and SB between 2014 and 2019 from two centres were included in this study. The primary outcome of this study was to determine csPC rates on TB and SB. The secondary outcome was a comparison of the Gleason Grade Group between TB and SB. csPC was defined as an International Society of Urological Pathology Gleason Grade Group of 2 or greater.

RESULTS

SB alone detected more csPC overall compared to TB (152/254 (60%) versus 128/254 (51%), respectively). An additional 40 of 254 (16%) csPC cases were diagnosed with the addition of SB. Furthermore, the cost of diagnosing insignificant prostate cancer by SB when TB were negative was an additional 13/254 (5.1%).

CONCLUSION

A combination of TB and SB provides the best outcomes for detecting csPC and is especially warranted for patients with a higher Prostate Imaging-Reporting and Data System score on multiparametric magnetic resonance imaging.

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.

Value of systematic sampling in an mp-MRI targeted prostate biopsy strategy

The clinical utility of systematic prostate biopsy in addition to multi-parametric magnetic resonance imagining (mp-MRI) targeted biopsy pathways remains unclear. Despite radiological advancements in mp-MRI and utilisation of international standardised reporting systems (i.e., PI-RADS, LIKERT), undetected clinically significant prostate cancer (csPCa) on imaging persists. This has prevented the widespread adoption of an exclusively targeted biopsy approach. The current evidence on csPCa cancer detection rates in mp-MRI targeted alone and combined with a non-targeted systematic sampling is presented. Arguments for and against routine limited systematic sampling as an adjunct to an mp-MRI targeted biopsy are discussed. Our review will report the clinical utility of a combined sampling strategy on csPCa detection rate. The available evidence suggests that we are yet to reach a stage where non-targeted systematic prostate biopsy can be routinely omitted in mp-MRI targeted prostate biopsy pathways. Research should focus on improving the accuracy of mp-MRI, prostate biopsy techniques, and in identifying those men that will most benefit from a combined prostate biopsy. Such strategies may help future urologists reduce the burden of non-targeted cores in modern mp-MRI prostate biopsy pathways.

Prostate Multiparametric Magnetic Resonance Imaging Features Following Partial Gland Cryoablation

OBJECTIVE

To assess the qualitative and quantitative changes on prostate multiparametric magnetic resonance imaging (mpMRI) following partial gland ablation (PGA) with cryotherapy and correlate with histopathology.

METHODS

We used 3D Slicer to generate prostate models and segment ipsilateral (treated) and contralateral peripheral and transition zones in 10 men who underwent MRI/transrectal ultrasound fusion-guided PGA during 2017-2018. Pre- and post-PGA volumes of prostate segments were compared. Post-PGA mpMRI were categorized according to PI-RADS v2 and treatment response on mpMRI was assessed in a manner similar to the radiology evaluation framework following liver lesion ablation.

RESULTS

Median volume of ipsilateral peripheral and transition zones decreased from 10.9 mL and 13.0 mL to 7.2 mL and 10.8 mL (P = .005), respectively. Median volume of contralateral peripheral and transition zones also decreased from 12.1 mL and 12.5 mL to 9.9 mL to 10.4 mL (P = .005), respectively. Five men had clinically significant disease (Grade group ≥2) on post-PGA biopsy (3 within treatment field and 2 outside). Of the men with clinically significant prostate cancer, mpMRI revealed PI-RADS 3 lesions in 2. However, the treatment response framework did not detect residual disease.

CONCLUSION

PGA results in asymmetrical and significant reductions in prostate volume. Our results highlight the need for a separate assessment framework to enable standardization of the interpretation and reporting of post-PGA surveillance mpMRI. Moreover, our findings have significant implications for MRI-targeted surveillance biopsy following PGA with cryotherapy.

Race and prostate imaging: implications for targeted biopsy and image-based prostate cancer interventions

Purpose

For men with an elevated prostate-specific antigen (PSA), there is a strong evidence for prostate MRI to assess the risk of clinically significant prostate cancer (CSPC) and guide targeted-biopsy interventions. Prostate MRI is assessed using the Prostate Imaging-Reporting and Data System (PI-RADS), which is scored from 1 to 5. Equivocal or suspicious findings (PI-RADS 3–5) are recommended for subsequent targeted biopsy, for which the risk of infection and sepsis is increasing. However, PI-RADS was developed primarily in men of European descent. We sought to elucidate PI-RADS and MRI-targeted biopsy outcomes in Asian men, a rapidly growing population in the USA, Europe, Australia and internationally.

Materials and methods

A prospective cohort of 544 men with elevated PSA without a diagnosis of prostate cancer who underwent MRI-targeted biopsy at our institution from January 2012 to December 2018 was analyzed. We categorized the cohort by self-designated race then used a validated algorithm which uses surname lists to identify a total of 78 (14%) Asian-Americans. The primary outcome was the likelihood of diagnosing CSPC (Gleason grade group >1) in Asian-Americans versus non-Asian-Americans. Multivariable logistic regression was used to determine the association of demographic and other characteristics with CSPC.

Results

Overall, MRI-targeted biopsy identified CSPC in 17% of Asian-American men versus 39% of non-Asian-American men (p<0.001). Notably for PI-RADS 3, only 6% of Asian-Americans versus 15% of others were diagnosed with CSPC. In adjusted analyses, Asian-American men were less likely to be diagnosed on MRI-targeted biopsy with CSPC (OR 0.30, 95% CI 0.14 to 0.65, p=0.002) and indolent prostate cancer (OR 0.37, 95% CI 0.15 to 0.91, p=0.030) than other races. Regardless of race those who were biopsy naïve were more likely (OR 2.25, 95% CI 1.45 to 3.49, p<0.001) to be diagnosed with CSPC.

Conclusion

We found that PI-RADS underperforms in Asian-American men. For instance, only 2 of 35 (6%) Asian-American men with PI-RADS 3 were diagnosed with CSPC on MRI targeted biopsy. This has significant implications for overuse of diagnostic and image-guided interventional approaches in Asian-Americans, given the increasing risk of infectious complications from biopsy. Additional validation studies are needed to confirm our findings.

Is There Still a Need for Repeated Systematic Biopsies in Patients with Previous Negative Biopsies in the Era of Magnetic Resonance Imaging-targeted Biopsies of the Prostate?

BACKGROUND

The role of targeted prostate biopsies (TBs) in patients with cancer suspicious lesions on multiparametric magnetic resonance imaging (mpMRI) following negative systematic biopsies (SBs) is undebated. However, whether they should be combined with repeated SBs remains unclear.

OBJECTIVE

To evaluate the value of repeated SBs in addition to TBs in patients with a prior negative SB and a persistent suspicion of prostate cancer (PCa).

DESIGN, SETTING, AND PARTICIPANTS

A prospective study as part of a multicenter randomized controlled trial conducted between 2014 and 2017, including 665 men with a prior negative SB and a persistent suspicion of PCa (suspicious digital rectal examination and/or prostate-specific antigen >4.0ng/ml).

INTERVENTION

All patients underwent 3T mpMRI according to Prostate Imaging Reporting and Data System (PI-RADS) v2. Patients with PI-RADS ≥3 were randomized 1:1:1 for three TB techniques: MRI-TRUS fusion TB (FUS-TB), cognitive registration fusion TB (COG-TB), or in-bore MRI TB. FUS-TB and COG-TB were combined with repeated SBs.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

Clinically significant prostate cancer (csPCa) was defined as Gleason ≥3+4. Differences in detection rates of csPCa, clinically insignificant PCa (cisPCa), and overall PCa between TBs (FUS-TB and COG-TB) and repeated SBs were compared using McNemar's test.

RESULTS AND LIMITATIONS

In the 152 patients who underwent both TB and SB, PCa was detected by TB in 47% and by SB in 32% (p<0.001, 95% confidence interval [CI]: 6.0-22%). TB detected significantly more csPCa than SB (32% vs 16%; p<0.001, 95% CI: 11-25%). Clinically significant PCa was missed by TB in 1.3% (2/152). Combining SB and TB resulted in detection rate differences of 6.0% for PCa, 5.0% for cisPCa, and 1.0% for csPCa compared with TB alone.

CONCLUSIONS

In case of a persistent suspicion of PCa following a negative SB, TB detected significantly more csPCa cases than SB. The additional value of SB was limited, and only 1.3% of csPCa would have been missed when SB had been omitted.

PATIENT SUMMARY

We evaluated the role of systematic biopsies and magnetic resonance imaging (MRI)-targeted biopsies for the diagnosis of prostate cancer in patients with prior negative systematic biopsies. MRI-targeted biopsies perform better in detecting prostate cancer in these patients. The value of repeated systematic biopsies is limited.

The primacy of multiparametric MRI in men with suspected prostate cancer

Background

Multiparametric MRI (mpMRI) became recognised in investigating those with suspected prostate cancer between 2010 and 2012; in the USA, the preventative task force moratorium on PSA screening was a strong catalyst. In a few short years, it has been adopted into daily urological and oncological practice. The pace of clinical uptake, born along by countless papers proclaiming high accuracy in detecting clinically significant prostate cancer, has sparked much debate about the timing of mpMRI within the traditional biopsy-driven clinical pathways. There are strongly held opposing views on using mpMRI as a triage test regarding the need for biopsy and/or guiding the biopsy pattern.

Objective

To review the evidence base and present a position paper on the role of mpMRI in the diagnosis and management of prostate cancer.

Methods

A subgroup of experts from the ESUR Prostate MRI Working Group conducted literature review and face to face and electronic exchanges to draw up a position statement.

Results

This paper considers diagnostic strategies for clinically significant prostate cancer; current national and international guidance; the impact of pre-biopsy mpMRI in detection of clinically significant and clinically insignificant neoplasms; the impact of pre-biopsy mpMRI on biopsy strategies and targeting; the notion of mpMRI within a wider risk evaluation on a patient by patient basis; the problems that beset mpMRI including inter-observer variability.

Conclusions

The paper concludes with a set of suggestions for using mpMRI to influence who to biopsy and who not to biopsy at diagnosis.

Key Points

• Adopt mpMRI as the first, and primary, investigation in the workup of men with suspected prostate cancer.

• PI-RADS assessment categories 1 and 2 have a high negative predictive value in excluding significant disease, and systematic biopsy may be postponed, especially in men with low-risk of disease following additional risk stratification.

• PI-RADS assessment category lesions 4 and 5 should be targeted; PI-RADS assessment category lesion 3 may be biopsied as a target, as part of systematic biopsies or may be observed depending on risk stratification.

Electronic supplementary material

The online version of this article (10.1007/s00330-019-06166-z) contains supplementary material, which is available to authorized users.

The Learning Curve for Magnetic Resonance Imaging/Ultrasound Fusion-guided Prostate Biopsy

BACKGROUND

Magnetic resonance imaging/ultrasound-guided fusion biopsy (FBx) is more accurate at detecting clinically significant prostate cancer than conventional transrectal ultrasound-guided systematic biopsy. However, learning curves for attaining accuracy may limit the generalizability of published outcomes.

OBJECTIVE

To delineate and quantify the learning curve for FBx by assessing the targeted biopsy accuracy and pathological quality of systematic biopsy over time.

DESIGN, SETTING, AND PARTICIPANTS

We carried out a retrospective analysis of 173 consecutive men who underwent Artemis FBx with computer-template systematic sampling between July 2015 and May 2017.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

The accuracy of targeted biopsy was determined by calculating the distance between planned and actual core trajectories stored on Artemis. Systematic sampling proficiency was assessed via pathological analysis of fibromuscular tissue in all cores and then comparing pathology elements from individual cores from men in the first and last tertiles. Polynomial linear regression models, change-point analysis, and piecewise linear regression were used to quantify the learning curve.

RESULTS AND LIMITATION

A significant improvement in targeted biopsy accuracy occurred up to 98 cases (p<0.01). There was a significant decrease in fibromuscular tissue in the systematic biopsy cores up to 84 cases (p<0.01) and an improvement in pathological quality when comparing systematic cores from the first and third tertiles. Use of a different fusion platform may limit the generalizability of our results.

CONCLUSIONS

There is a significant learning curve for targeted and systemic biopsy using the Artemis platform. Improvements in accuracy of targeted biopsy and better sampling for systematic biopsy can be achieved with greater experience.

PATIENT SUMMARY

We define the learning curve for magnetic resonance imaging/ultrasound-guided fusion biopsy (FBx) using targeted biopsy accuracy and systematic core sampling quality as measures. Our findings underscore the importance of overcoming learning curves inherent to FBx to minimize patient discomfort and biopsy risk and improve the quality of care for accurate risk stratification, active surveillance, and treatment selection.