The role of the multiparametric MRI in the diagnosis of prostate cancer in biopsy-naïve men

Transperineal Versus Transrectal Magnetic Resonance Imaging-targeted Biopsies for Prostate Cancer Diagnosis: Final Results of the Randomized PERFECT trial (CCAFU-PR1)

BACKGROUND

Recent guidelines favor transperineal (TP) prostate biopsies over the transrectal (TR) approach due to a reduced sepsis risk. Yet, evidence from controlled trial comparing both approaches within the MRI-targeted pathway for significant prostate cancer (PCa) detection is lacking.

OBJECTIVE

To compare the significant PCa detection rate between magnetic resonance imaging (MRI)-targeted TR and TP approaches in biopsy-naïve patients.

DESIGN, SETTING, AND PARTICIPANTS

In this noninferiority controlled trial, we randomized (ratio 1:1) 270 MRI-positive biopsy-naïve patients.

INTERVENTION

MRI-targeted TP versus TR biopsy.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSES

The primary outcome was the detection rate of significant PCa (International Society of Urological Pathology [ISUP] ≥2) in MRI-targeted biopsies. Secondary outcomes were any-grade PCa detection, detection on concomitant systematic biopsy, complications, and functional outcomes.

RESULTS AND LIMITATIONS

Targeted biopsies identified significant PCa in 47.2% of TP and 54.2% of TR participants (-7%, p = 0.6235). On a per-lesion analysis, posterior lesions yielded higher detection rates via TR (59.0% vs 44.3%, p = 0.0443), while anterior lesions were more frequently detected via TP (40.6% vs 26.5%, p = 0.2228). The overall (any grade) cancer detection rate in targeted biopsies was comparable between groups: 71.3% (TP) versus 64.1% (TR; p = 0.2209) with significantly more ISUP 1 cases detected in the TP arm. Adverse events of grade ≥2 were not different between TP (35.7%) and TR (40.5%, p = 0.4256). One TR patient (0.8%) experienced grade 3 sepsis. Quality of life, and urinary and sexual function, as well as pain scores, were comparable between groups.

CONCLUSIONS

Despite a comparable overall detection rate for any-grade PCa, noninferiority of TP over TR for MRI-targeted biopsies for significant PCa detection was not demonstrated. However, MRI lesion location influenced biopsy route performance, suggesting that a pragmatic approach based on lesion location might enhance significant PCa assessment.

PATIENT SUMMARY

This trial compared the efficacy and safety of two biopsy approaches for prostate cancer diagnosis. Both approaches seem complementary according to the lesion location.

Comparison of MRI/US Fusion Targeted Biopsy and Systematic Biopsy in Biopsy-Naïve Prostate Patients with Elevated Prostate-Specific Antigen: A Diagnostic Study

Purpose

This study aimed to compare the detection rate of prostate cancer (PCa) between targeted biopsy and systematic biopsy.

Patients and Methods

A total of 671 patients who underwent both targeted biopsy and systematic biopsy were included in this study. The stratified analysis was conducted based on Prostate Imaging Reporting and Data System (PIRADS) scores, region of interest load (ROI-load).

Results

There was no statistical difference in the detection rate of PCa patients between systematic biopsy and targeted biopsy (44.41% vs 45.6%, P>0.05), while the detection rate of targeted biopsy in clinically significant PCa (csPCa) patients was slightly higher than that of systematic biopsy (40.83% vs 38.15%, P=0.033). Stratified analysis indicated that targeted biopsy was more advantageous in csPCa patients with PIRADS score ≥ 4 and ROI-load > 5%. The comparison of diagnostic sensitivity of systematic biopsy and targeted biopsy demonstrated that targeted biopsy was more sensitive than systematic biopsy to diagnose PCa (Z=2.110, P=0.035) at ROI-load ≤ 5%. In addition, ROI-load may be a better targeted biopsy indicator than ROI diameter for the diagnosis of PCa (Z=2.168, P=0.030).

Conclusion

MRI/US fusion targeted biopsy may be more suitable for PCa detection than systematic biopsy in patients with low ROI-load.

Incidental prostate cancer after holmium laser enucleation of the prostate-A narrative review

Prostate cancer can be detected incidentally after surgical therapy for benign prostatic obstruction such as holmium laser enucleation of the prostate (HoLEP), thus called incidental prostate cancer (iPCa). We aimed to review the studies on iPCa detected after HoLEP and investigate its prevalence. A detailed search of original articles was conducted via the PubMed-MEDLINE, Web of Science, Wiley Online Library and Cochrane Library databases in the last 10 years up to 1 May 2021 with the following search string solely or in combination: "prostate cancer", "prostate carcinoma", "holmium laser enucleation of the prostate" and "HoLEP". We identified 19 articles to include in our analysis and divided them into six main categories: HoLEP versus open prostatectomy and/or transurethral resection of the prostate in terms of iPCa, oncological and functional outcomes, the role of imaging modalities in detecting iPCa, predictive factors of iPCa, the role of prostate-specific antigen kinetics in detecting iPCa and the management of iPCa after HoLEP. We found that the iPCa after HoLEP rate ranges from 5.64% to 23.3%. Functional and oncological outcomes were reported to be encouraging. Oncological treatment options are available in a wide range.

Usefulness of MRI targeted prostate biopsy for detecting clinically significant prostate cancer in men with low prostate-specific antigen levels

We aimed to evaluate the detection rates of prostate cancer (PCa) and clinically significant PCa (csPCa) using magnetic resonance imaging-targeted biopsy (MRI-TBx) in men with low prostate-specific antigen (PSA) levels (2.5–4.0 ng/mL). Clinicopathologic data of 5502 men with PSA levels of 2.5–10.0 ng/mL who underwent transrectal ultrasound-guided biopsy (TRUS-Bx) or MRI-TBx were reviewed. Participants were divided into four groups: LP-T [low PSA (2.5–4.0 ng/mL) and TRUS-Bx, n = 2018], LP-M (low PSA and MRI-TBx, n = 186), HP-T [high PSA (4.0–10.0 ng/mL) and TRUS-Bx, n = 2953], and HP-M (high PSA and MRI-TBx, n = 345). The detection rates of PCa and csPCa between groups were compared, and association of biopsy modality with detection of PCa and csPCa in men with low PSA levels were analyzed. The detection rates of PCa (20.0% vs. 38.2%; P < 0.001) and csPCa (11.5% vs. 32.3%; P < 0.001) were higher in the LP-M group than in the LP-T group. Conversely, there were no significant differences in the detection rates of PCa (38.2% vs. 43.2%; P = 0.263) and csPCa (32.3% vs. 39.4%; P = 0.103) between the LP-M and HP-M groups. Multivariate analyses revealed that using MRI-TBx could predict the detection of csPCa (odds ratio 2.872; 95% confidence interval 1.996‒4.132; P < 0.001) in men with low PSA levels. In summary, performing MRI-TBx in men with low PSA levels significantly improved the detection rates of PCa and csPCa as much as that in men with high PSA levels.

Preoperative multiparametric prostate magnetic resonance imaging: a safe clinical practice to reduce incidental prostate cancer in Holmium laser enucleation of the prostate

Introduction

Purpose of the study was to investigate the correlation of a preoperative multiparametric magnetic resonance imaging of the prostate (mpMRI) in patients with a suspicion of prostate cancer and eligible for Holmium Laser Enucleation of the Prostate (HoLEP).

Material and methods

Data of 228 patients who had undergone HoLEP was selected and retrospectively analyzed from a multicentric database. All patients presented with a raised serum PSA and/or an abnormal digital rectal examination (DRE). Prostate cancer (PCa) was excluded either with a negative mpMRI (group ‘NEGATIVE MRI’ n = 113) or a standard biopsy (group ‘NO MRI’ n = 115). Preoperative characteristic surgical and histological outcomes were confronted. A univariate and multivariate logistic regression model was performed to investigate independent predictors of incidental Prostate Cancer (iPCa).

Results

Both groups presented with no statistical differences in preoperative characteristics besides previous acute urinary retention rates and post-voided residual volume, found to be higher (27.8% vs. 14.2% and median 120cc vs. 80cc) in NO MRI and NEGATIVE MRI respectively.

No differences were registered in surgical time, removed tissue, catheterization time, hospital stay and complications rate.

Statistically lower rate of iPCa (p = 0.03) was detected in the NEGATIVE MRI group (6.2%) in comparison with NO MRI group (14.8%). In multivariate logistic regression only presence of a preoperative negative mpMRI correlated (p = 0.04) as an independent predictive factor (OR 2.63; 95% CI: 1.02–6.75).

Conclusions

A negative mpMRI might be a useful tool to be included in a novel preoperative assessment to patients eligible for HoLEP with a suspicion of PCa in order to avoid an incidental PCa.

Prostate zonal segmentation in 1.5T and 3T T2W MRI using a convolutional neural network

Zonal segmentation of the prostate gland using magnetic resonance imaging (MRI) is clinically important for prostate cancer (PCa) diagnosis and image-guided treatments. A two-dimensional convolutional neural network (CNN) based on the U-net architecture was evaluated for segmentation of the central gland (CG) and peripheral zone (PZ) using a dataset of 40 patients (34 PCa positive and 6 PCa negative) scanned on two different MRI scanners (1.5T GE and 3T Siemens). Images were cropped around the prostate gland to exclude surrounding tissues, resampled to 0.5 × 0.5 × 0.5    mm   voxels and z -score normalized before being propagated through the CNN. Performance was evaluated using the Dice similarity coefficient (DSC) and mean absolute distance (MAD) in a fivefold cross-validation setup. Overall performance showed DSC of 0.794 and 0.692, and MADs of 3.349 and 2.993 for CG and PZ, respectively. Dividing the gland into apex, mid, and base showed higher DSC for the midgland compared to apex and base for both CG and PZ. We found no significant difference in DSC between the two scanners. A larger dataset, preferably with multivendor scanners, is necessary for validation of the proposed algorithm; however, our results are promising and have clinical potential.

Assessment of prostate cancer prognostic Gleason grade group using zonal-specific features extracted from biparametric MRI using a KNN classifier

Purpose

To automatically assess the aggressiveness of prostate cancer (PCa) lesions using zonal‐specific image features extracted from diffusion weighted imaging (DWI) and T2W MRI.

Methods

Region of interest was extracted from DWI (peripheral zone) and T2W MRI (transitional zone and anterior fibromuscular stroma) around the center of 112 PCa lesions from 99 patients. Image histogram and texture features, 38 in total, were used together with a k‐nearest neighbor classifier to classify lesions into their respective prognostic Grade Group (GG) (proposed by the International Society of Urological Pathology 2014 consensus conference). A semi‐exhaustive feature search was performed (1–6 features in each feature set) and validated using threefold stratified cross validation in a one‐versus‐rest classification setup.

Results

Classifying PCa lesions into GGs resulted in AUC of 0.87, 0.88, 0.96, 0.98, and 0.91 for GG1, GG2, GG1 + 2, GG3, and GG4 + 5 for the peripheral zone, respectively. The results for transitional zone and anterior fibromuscular stroma were AUC of 0.85, 0.89, 0.83, 0.94, and 0.86 for GG1, GG2, GG1 + 2, GG3, and GG4 + 5, respectively.

CONCLUSION

This study showed promising results with reasonable AUC values for classification of all GG indicating that zonal‐specific imaging features from DWI and T2W MRI can be used to differentiate between PCa lesions of various aggressiveness.

Implementation of a 5-Minute Magnetic Resonance Imaging Screening Protocol for Prostate Cancer in Men With Elevated Prostate-Specific Antigen Before Biopsy

PURPOSE

The aims of this study were to establish a 5-minute magnetic resonance (MR) screening protocol for prostate cancer in men before biopsy and to evaluate effects on Prostate Imaging Reporting and Data System (PI-RADS) V2 scoring in comparison to a conventional, fully diagnostic multiparametric MR imaging (mpMRI) approach.

MATERIALS AND METHODS

Fifty-two patients with elevated prostate-specific antigen levels and without prior biopsy were prospectively included in this institutional review board-approved study. In all patients, an mpMRI protocol according to the PI-RADS recommendations was acquired on a 3 T MRI system. In addition, an accelerated diffusion-weighted imaging sequence was acquired using simultaneous multislice technique (DW-EPISMS). Two readers independently evaluated the images for the presence/absence of prostate cancer according to the PI-RADS criteria and for additional findings. In a first reading session, only the screening protocol consisting of axial T2-weighted and DW-EPISMS images was made available. In a subsequent reading session, the mpMRI protocol was assessed blinded to the results of the first reading, serving as reference standard.

RESULTS

Both readers successfully established a final diagnosis according to the PI-RADS criteria in the screening and mpMRI protocol. Mean lesion size was 1.2 cm in the screening and 1.4 cm in the mpMRI protocol (P = 0.4) with 35% (18/52) of PI-RADS IV/V lesions. Diagnostic performance of the screening protocol was excellent with a sensitivity and specificity of 100% for both readers with no significant differences in comparison to the mpMRI standard (P = 1.0). In 3 patients, suspicious lymph nodes were reported as additional finding, which were equally detectable in the screening and mpMRI protocol.

CONCLUSIONS

A 5-minute MR screening protocol for prostate cancer in men with elevated prostate-specific antigen levels before biopsy is applicable for clinical routine with similar diagnostic performance as the full diagnostic mpMRI approach.

Diagnostic Accuracy of a Rapid Biparametric MRI Protocol for Detection of Histologically Proven Prostate Cancer

OBJECTIVE

To evaluate the performance of a rapid, low cost, noncontrast MRI examination as a secondary screening tool in detection of clinically significant prostate cancer.

METHODS

In this prospective single institution study, 129 patients with elevated prostate-specific antigen levels or abnormal digital rectal examination findings underwent MRI with an abbreviated biparamatric MRI protocol consisting of high-resolution axial T2- and diffusion-weighted images. Index lesions were classified according to modified Prostate Imaging - Reporting and Data System (mPI-RADS) version 2.0. All patients underwent standard transrectal ultrasound-guided biopsy after MRI with the urologist being blinded to MRI results. Subsequently, all patients with suspicious lesions (mPI-RADS 3, 4, or 5) underwent cognitively guided targeted biopsy after discussion of MRI results with the urologist. Sensitivity and negative predictive value for identification of clinically significant prostate cancer (Gleason score 3+4 and above) were determined.

RESULTS

Rapid biparametric MRI discovered 176 lesions identified in 129 patients. Rapid MRI detected clinically significant cancers with a sensitivity of 95.1% with a negative predictive value of 95.1% and positive predictive value of 53.2%, leading to a change in management in 10.8% of the patients. False negative rate of biparametric (bp) MRI was 4.7%.

CONCLUSION

We found that a bp-MRI examination can detect clinically significant lesions and changed patient management in 10.8% of the patients. A rapid MRI protocol can be used as a useful secondary screening tool in men presenting with suspicion of prostate cancer.

Prospective comparison of PI-RADS version 2 and qualitative in-house categorization system in detection of prostate cancer

BACKGROUND

Prostate Imaging-Reporting and Data System v. 2 (PI-RADSv2) provides standardized nomenclature for interpretation of prostate multiparametric MRI (mpMRI). Inclusion of additional features for categorization may provide benefit to stratification of disease.

PURPOSE

To prospectively compare PI-RADSv2 to a qualitative in-house system for detecting prostate cancer on mpMRI.

STUDY TYPE

Prospective.

POPULATION

In all, 338 patients who underwent mpMRI May 2015-May 2016, with subsequent MRI/transrectal ultrasound fusion-guided biopsy.

FIELD STRENGTH

3T mpMRI (T2 W, diffusion-weighted [DW], apparent diffusion coefficient [ADC] map, b-2000 DWI acquisition, and dynamic contrast-enhanced [DCE] MRI).

ASSESSMENT

One genitourinary radiologist prospectively read mpMRIs using both in-house and PI-RADSv2 5-category systems.

STATISTICAL TEST

In lesion-based analysis, overall and clinically significant (CS) tumor detection rates (TDR) were calculated for all PI-RADSv2 and in-house categories. The ability of each scoring system to detect cancer was assessed by area under receiver operator characteristic curve (AUC). Within each PI-RADSv2 category, lesions were further stratified by their in-house categories to determine if TDRs can be increased by combining features of both systems.

RESULTS

In 338 patients (median prostate-specific antigen [PSA] 6.5 [0.6-113.6] ng/mL; age 64 [44-84] years), 733 lesions were identified (47% tumor-positive). Predictive abilities of both systems were comparable for all (AUC 76-78%) and CS cancers (AUCs 79%). The in-house system had higher overall and CS TDRs than PI-RADSv2 for categories 3 and 4 (P < 0.01 for both), with the greatest difference between the scoring systems seen in lesions scored category 4 (CS TDRs: in-house 65%, PI-RADSv2 22.1%). For lesions categorized as PI-RADSv2 = 4, characterization of suspicious/indeterminate extraprostatic extension (EPE) and equivocal findings across all mpMRI sequences contributed to significantly different TDRs for both systems (TDR range 19-75%, P < 0.05).

DATA CONCLUSION

PI-RADSv2 behaves similarly to an existing validated system that relies on the number of sequences on which a lesion is seen. This prospective evaluation suggests that sequence positivity and suspicion of EPE can enhance PI-RADSv2 category 4 cancer detection.

LEVEL OF EVIDENCE

1 Technical Efficacy: Stage 3 J. Magn. Reson. Imaging 2018;47:1326-1335.

MRI-Targeted or Standard Biopsy for Prostate-Cancer Diagnosis

BACKGROUND

Multiparametric magnetic resonance imaging (MRI), with or without targeted biopsy, is an alternative to standard transrectal ultrasonography-guided biopsy for prostate-cancer detection in men with a raised prostate-specific antigen level who have not undergone biopsy. However, comparative evidence is limited.

METHODS

In a multicenter, randomized, noninferiority trial, we assigned men with a clinical suspicion of prostate cancer who had not undergone biopsy previously to undergo MRI, with or without targeted biopsy, or standard transrectal ultrasonography-guided biopsy. Men in the MRI-targeted biopsy group underwent a targeted biopsy (without standard biopsy cores) if the MRI was suggestive of prostate cancer; men whose MRI results were not suggestive of prostate cancer were not offered biopsy. Standard biopsy was a 10-to-12-core, transrectal ultrasonography-guided biopsy. The primary outcome was the proportion of men who received a diagnosis of clinically significant cancer. Secondary outcomes included the proportion of men who received a diagnosis of clinically insignificant cancer.

RESULTS

A total of 500 men underwent randomization. In the MRI-targeted biopsy group, 71 of 252 men (28%) had MRI results that were not suggestive of prostate cancer, so they did not undergo biopsy. Clinically significant cancer was detected in 95 men (38%) in the MRI-targeted biopsy group, as compared with 64 of 248 (26%) in the standard-biopsy group (adjusted difference, 12 percentage points; 95% confidence interval [CI], 4 to 20; P=0.005). MRI, with or without targeted biopsy, was noninferior to standard biopsy, and the 95% confidence interval indicated the superiority of this strategy over standard biopsy. Fewer men in the MRI-targeted biopsy group than in the standard-biopsy group received a diagnosis of clinically insignificant cancer (adjusted difference, -13 percentage points; 95% CI, -19 to -7; P<0.001).

CONCLUSIONS

The use of risk assessment with MRI before biopsy and MRI-targeted biopsy was superior to standard transrectal ultrasonography-guided biopsy in men at clinical risk for prostate cancer who had not undergone biopsy previously. (Funded by the National Institute for Health Research and the European Association of Urology Research Foundation; PRECISION ClinicalTrials.gov number, NCT02380027 .).

Handling and reporting of transperineal template prostate biopsy in Europe: a web-based survey by the European Network of Uropathology (ENUP)

Transperineal template prostate biopsies (TTPB) are performed for assessments after unexpected negative transrectal ultrasound biopsies (TRUSB), correlation with imaging findings and during active surveillance. The impact of TTPBs on pathology has not been analysed. The European Network of Uropathology (ENUP) distributed a survey on TTPB, including how specimens were received, processed and analysed. Two hundred forty-four replies were received from 22 countries with TTPBs seen by 68.4% of the responders (n = 167). Biopsies were received in more than 12 pots in 35.2%. The number of cores embedded per cassette varied between 1 (39.5%) and 3 or more (39.5%). Three levels were cut in 48.3%, between 2 and 3 serial sections in 57.2% and unstained spare sections in 45.1%. No statistical difference was observed with TRUSB management. The number of positive cores was always reported and the majority gave extent per core (82.3%), per region (67.1%) and greatest involvement per core (69.4%). Total involvement in the whole series and continuous/discontinuous infiltrates were reported in 42.2 and 45.4%, respectively. The majority (79.4%) reported Gleason score in each site or core, and 59.6% gave an overall score. A minority (28.5%) provided a map or a diagram. For 19%, TTPB had adversely affected laboratory workload with only 27% managing to negotiate extra costs. Most laboratories process samples thoroughly and report TTPB similarly to TRUSB. Although TTPB have caused considerable extra work, it remains uncosted in most centres. Guidance is needed for workload impact and minimum standards of processing if TTPB work continues to increase.