Analysis of PI-RADS 4 cases: Management recommendations for negatively biopsied patients

Evaluation of the current status, significance, and availability of prostate MRI und MRI guided biopsy in Germany

Evaluation of the current status, significance and availability of multiparametric prostate MRI and MRI-guided biopsy in Germany.A voluntary web-based questionnaire with 26 distinct items was emailed to members of the German Radiological Society (DRG) and the Professional Association of German Radiologists (BDR). The questions referred to personal qualification, acquisition, quality, and management of prostate MRI, and assessment of the importance of the method.In total 182 questionnaires were captured from all 10 german postal regions (over 60% of the university hospitals, almost 50% of the maximum care hospitals and approx. 12% of the practices or medical service centers). 43% of the respondents had a Q1 or Q2 quality certificate from the DRG, 10% had a certificate from the BDR, respectively. The majority (90%) criticized inadequate reimbursement of the examination. In 47% MRI cases were discussed in an interdisciplinary tumor board, in 44% case discussions happened rarely, and 12% never had interdisciplinary discussions. On a scale from 0-100 (0%: low; 100%: high) the estimation of the clinical relevance of prostate MRIs received an average of 84% (± 16%) and the estimated approval by urologists was 75% (± 21%). Lacking clinical feedback (59%) and clinical information (42%) were perceived as the largest problems.In this representative survey the respondents estimated multiparametric MRI of the prostate as highly diagnostic and relevant with an increased approval by urologists. There is still a perceived need for continuous professional education of the method for urologists and for more widespread coverage of fusion biopsy. Prostate MRI is currently primarily offered by high volume centers. Current challenges are particularly insufficient interdisciplinary communication and inadequate reimbursement. · Prostate MRI is perceived as highly diagnostic and clinically relevant.The method is currently primarily offered by high volume centers.. · Bigger current problems are insufficient interdisciplinary communication (e.g., clinical information, biopsy results) and inadequate reimbursement.. · Continuous education for urologists and expanded coverage by fusion biopsy are desirable.. · Ullrich T, Boschheidgen M, Schweyen CM et al. Evaluation of the current status, significance, and availability of prostate MRI und MRI guided biopsy in germany. Fortschr Röntgenstr 2024; DOI 10.1055/a-2416-1343.

Natural history of histologically benign PIRADS 4-5 lesions in multiparametric MRI: Real-life experience in an academic center

INTRODUCTION

The follow-up findings of patients who underwent prostate biopsy for prostate image reporting and data system (PIRADS) 4 or 5 multiparametric magnetic resonance imaging (mpMRI) findings and had benign histology were retrospectively reviewed.

METHODS

There were 190 biopsy-naive patients. Patients with at least 12 months of follow-up between 2012 and 2023 were evaluated. All MRIs were interpreted by two very experienced uroradiologists. Of the patients, 125 had either cognitive or software fusion MR-targeted biopsies with 4 + 8/10 cores. The remaining 65 patients had in-bore biopsies with 4-5 cores. Prostate-specific antigen (PSA) levels below 4 ng/mL were defined as PSA regression following biopsy. PIRADS 1-3 lesions on new MRI images were classified as MRI regression.

RESULTS

Median patient age and PSA were 62 (39-82) years and six (0.4-33) ng/mL, respectively, at the initial work-up. During a median follow-up period of 44 months, 37 (19.4%) patients were lost to follow-up. Of the remaining 153 patients, 82 (53.6%) had persistently high PSA. Among them, 72 (87.8%) had repeat mpMRI within 6-24 months which showed regressive findings (PIRADS 1-3) in 53 patients (73.6%) and PIRADS 4-5 index lesion persistence in 19 cases (26.4%). The latter group was recommended to have rebiopsy. Of these 19 patients, 16 underwent MRI-targeted rebiopsy. Prostate cancer was diagnosed in six (37.5%) patients and of these four (25%) were clinically significant (>Grade Group 1). Totally, clinically significant prostate cancer was detected in 4/153 (2.6%) patients followed up.

CONCLUSION

Patients should be warned against the relative relaxing effect of a negative biopsy after identification of PIRADS 4-5 index lesion. While PSA decrease was observed in many patients during follow-up, persistent MRI findings were present in nearly a quarter of patients with persistently high PSA. A rebiopsy is warranted in these patients, with significant prostate cancer diagnosed in a quarter of patients with rebiopsy.

Multiparametric MRI characteristics of prostatitis and atrophy in the peripheral zone in men without prostate cancer

PURPOSE

To analyse multiparametric magnetic resonance imaging (mpMRI) characteristics and appearance of histopathologically proven non-cancerous intraprostatic findings focussing on quantity of prostatitis and atrophy in the peripheral zone.

METHOD

In this retrospective analysis consecutive patients with mpMRI followed by MRI/TRUS-fusion biopsy comprising targeted (TB) and systematic biopsy (SB) cores without prostate cancer (PC) at histopathology were included. Subgroup analysis was performed in younger men (≤50 years). The proportions of prostatitis and atrophy were quantified for each biopsy core based on histopathology. MRI findings in the peripheral zone (PZ) and index lesions (IL, most suspicious/representative lesion) were characterized regarding changes in T2w, ADC value, and enhancement of dynamic contrast enhancement (DCE) and correlated with quantity of prostatitis and atrophy.

RESULTS

Seventy-two patients were analysed. The median baseline characteristics were PSA 5.4 ng/ml (4.0-7.9), PI-RADS classification 3 (2-4), prostate volume 43 ml (33-57), and PSA density 0.13 ng/ml2 (0.10-0.19). Prostatitis was found in 44 % (n = 32) and atrophy in 65 % (n = 47) of cases. The quantity of atrophy demonstrated a significant correlation to T2w changes, ADC increase and DCE enhancement (p = 0.05, p = 0.05, p = 0.01), whereas quantity of prostatitis did not show any significant correlation to the MRI changes (p = 0.68, p = 0.58, p = 0.95). Quantity of prostatitis and atrophy increased with PI-RADS classification. Younger men had lower PSA (4.4 vs. 7.8 ml/ng; p < 0.001), smaller prostate volume (40 vs. 59 ml; p = 0.001), and lower PI-RADS classification (2-3 vs. 3-4; p = 0.005) and prostatitis and atrophy were less frequently observed (p ≤ 0.01, p = 0.03).

CONCLUSIONS

Quantity of atrophy and prostatitis had different influence on MRI characteristics and increased within higher PI-RADS classification. Younger men had diffuse hypointense changes at T2w images, but less quantity of prostatitis and atrophy.

Clinical value of minimum apparent diffusion coefficient for prediction of clinically significant prostate cancer in the transition zone

BACKGROUND

This study investigated the association between apparent diffusion coefficients in Prostate Imaging Reporting and Data System 4/5 lesions and clinically significant prostate cancer in the transition zone.

METHODS

We included 102 patients who underwent transperineal cognitive fusion targeted biopsy for Prostate Imaging Reporting and Data System 4/5 lesions in the transition zone between 2016 and 2020. The association between apparent diffusion coefficients and prostate cancers in the transition zone was analyzed.

RESULTS

The detection rate of prostate cancer was 49% (50/102), including clinically significant prostate cancer in 37.3% (38/102) of patients. The minimum apparent diffusion coefficients in patients with clinically significant prostate cancer were 494.5 ± 133.6 µm2/s, which was significantly lower than 653.8 ± 172.5 µm2/s in patients with benign histology or clinically insignificant prostate cancer. Age, prostate volume, transition zone volume, and mean and minimum apparent diffusion coefficients were associated with clinically significant prostate cancer. Multivariate analysis demonstrated that only the minimum apparent diffusion coefficient value (odds ratio: 0.994; p < 0.001) was an independent predictor of clinically significant prostate cancer. When the cutoff value of the minimum apparent diffusion coefficient was less than 595 µm2/s, indicating the presence of prostate cancer in the transition zone, the detection rate increased to 59.2% (29/49) in this cohort.

CONCLUSION

The minimum apparent diffusion coefficient provided additional value to indicate the presence of clinically significant prostate cancer in the transition zone. It may help consider the need for subsequent biopsies in patients with Prostate Imaging Reporting and Data System 4/5 lesions and an initial negative targeted biopsy.

Follow-up of men with a PI-RADS 4/5 lesion after negative MRI/Ultrasound fusion biopsy

Magnetic resonance imaging/Ultrasound (MRI/US) fusion targeted biopsy (TB) in combination with a systematic biopsy (SB) improves cancer detection but limited data is available how to manage patients with a Prostate Imaging-Reporting and Data System (PI-RADS) ≥ 4 lesion and a negative biopsy. We evaluate the real-world management and the rate of clinically significant Prostate Cancer (csPCa) during follow-up. 1546 patients with a multi-parametric MRI (mpMRI) and a PI-RADS ≥ 3 who underwent SB and TB between January 2012 and May 2017 were retrospectively analyzed. 222 men with a PI-RADS ≥ 4 and a negative biopsy were included until 2019. For 177/222 (80%) complete follow-up data was obtained. 66/84 (78%) had an initial PI-RADS 4 and 18 (22%) a PI-RADS 5 lesion. 48% (84/177) received a repeat mpMRI; in the follow-up mpMRI, 39/84 (46%) lesions were downgraded to PI-RADS 2 and 11 (13%) to PI-RADS 3; three cases were upgraded and 28 lesions remained consistent. 18% (32/177) men underwent repeated TB and csPCa was detected in 44% (14/32). Our study presents real world data on the management of men with a negative TB biopsy. Men with a positive mpMRI and lesions with high suspicion (PI-RADS4/5) and a negative targeted biopsy should be critically reviewed and considered for repeat biopsy or strict surveillance. The optimal clinical risk assessment remains to be further evaluated.

Comparison and prediction of artefact severity due to total hip replacement in 1.5 T versus 3 T MRI of the prostate

PURPOSE

To evaluate image quality and diagnostic value of multiparametric prostate MRI (mpMRI) in patients with total hip replacement (THR) at 1.5 and 3 Tesla.

METHODS

In this retrospective multicenter cohort study patients with uni- or bilateral THR and 1.5 T or 3 T mpMRI were included. Seventy consecutive, standard-of-care examinations per field strength were evaluated regarding their diagnostic value. The overall diagnostic value and prostate imaging quality score (PI-QUAL) were assessed. Artifact severity in the localizer and mpMRI sequences (T2w, DWI, DCE) was scored on a 3-point scale. Correlation between diagnostic value and artifacts was analysed. Moreover, a subgroup analysis focussed on image quality at different 3 T scanner generations.

RESULTS

140 consecutive patients (mean age 72, median PSA value 8.3 ng/ml) were included. When comparing 1.5 T to 3 T examinations, no significant differences were observed regarding the artifact severity of DWI and the localizer and the overall diagnostic value of the images. There was a strong correlation between the diagnostic value, PI-QUAL score, and artifact severity in the localizer and DWI. T2w and DCE sequences showed overall low artifacts. Significant improvement in image quality for 3 T at the latest scanner generation was observed, especially for DWI (p < 0.03).

CONCLUSIONS

MpMRI of patients with THR can be conducted at both field strengths without significant differences in artifacts. The localizer might be useful as an early forecasting feature for diagnostic value and particularly for contrast medium application decision. Patients with THR could benefit from technically advanced scanner generation and rs/ptx-EPI DWI sequences.

Impact of different phased-array coils on the quality of prostate magnetic resonance images

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Image quality is similar for different body phased-array receive coil setups.

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An 18-channel body phased-array receive coil setup achieved good image quality.

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60-channel body phased-array receive coil setup slightly improves SNR in T2W images.

Purpose

To evaluate the influence of body phased-array (BPA) receive coil setups on signal-to-noise ratio (SNR) and image quality (IQ) in prostate MRI.

Methods

This prospective study evaluated axial T2-weighted images (T2W-TSE) and DWI of the prostate in ten healthy volunteers with 18-channel (18CH), 30-channel and 60-channel (60CH) BPA receive coil setups. SNR and ADC values were assessed in the peripheral and transition zones (TZ). Two radiologists rated IQ features. Differences in qualitative and quantitative image features between BPA receive coil setups were compared. After correction for multiple comparisons, p-values <0.004 for quantitative and p-values <0.017 for qualitative image analysis were considered statistically significant.

Results

Significantly higher SNR was found in T2W-TSE images in the TZ using 60CH BPA compared to 18CH BPA coil setups (15.20 ± 4.22 vs. 7.68 ± 2.37; p = 0.001). There were no significant differences between all other quantitative (T2W-TSE, p = 0.007−0.308; DWI, p = 0.024−0.574) and qualitative image features (T2W-TSE, p = 0.083–1.0; DWI, p = 0.046–1.0).

Conclusion

60CH BPA receive coil setup showed marginal SNR improvement in T2W-TSE images. Good IQ could be achieved with 18CH BPA coil setups.

Probability of Prostate Cancer Diagnosis following Negative Systematic and Targeted MRI: Transrectal Ultrasound Fusion Biopsy: A Real-Life Observational Study

INTRODUCTION

The risk of occult prostate carcinoma (PCa) after negative multiparametric MRI (mpMRI)-transrectal fusion biopsy (F-Bx) is unknown. To determine the false-negative predictive value, we examined PCa detection after prior negative F-Bx.

METHODS

Between December 2012 and November 2016, 491 patients with suspected PCa and suspicious mpMRI findings underwent transrectal F-Bx. Patients with benign pathology (n = 191) were eligible for our follow-up (FU) survey. Patient characteristics and clinical parameters were correlated to subsequent findings of newly detected PCa.

RESULTS

Complete FU with a median of 31 (interquartile range: 17-39) months was available for 176/191 (92.2%) patients. Of those, 54 men had either surgical interventions on the prostate or re-Bxs. Newly detected PCa was evident in 14/176 (7.95%) patients stratified to ISUP ≤2 in 10 and ≥3 in 4 cases. The comparison of patients with newly detected PCa to those without cancerous findings in FU showed significant differences in prostate-specific antigen (PSA) density (0.16 vs. 0.13 ng/mL2) and prostate volume (45 vs. 67 mL, both p < 0.05). Both factors are significant predictors for newly detected cancer after initial negative F-Bx.

CONCLUSION

Only PSA density (>0.13 ng/mL2) and small prostate volume are significant predictors for newly detected PCa after initial negative F-Bx. Despite negative mpMRI/TRUS F-Bx results, patients should be further monitored due to a risk of developing PCa over time. Notwithstanding the limitation of our study that not all patients underwent another Bx, we assume that the false-negative rate is low but existing. Our data represent a real-world scenario.

Positive Predictive Value of Prostate Imaging Reporting and Data System Version 2 for the Detection of Clinically Significant Prostate Cancer: A Systematic Review and Meta-analysis

CONTEXT

The variability of the positive predictive value (PPV) represents a significant factor affecting the diagnostic performance of multiparametric magnetic resonance imaging (mpMRI).

OBJECTIVE

To analyze published studies reporting mpMRI PPV and the reasons behind the variability of clinically significant prostate cancer (csPCa) detection rates on targeted biopsies (TBx) according to Prostate Imaging Reporting and Data System (PI-RADS) version 2 categories.

EVIDENCE ACQUISITION

A search of PubMed, Cochrane library's Central, EMBASE, MEDLINE, and Scopus databases, from January 2015 to June 2020, was conducted. The primary and secondary outcomes were to evaluate the PPV of PI-RADS version 2 in detecting csPCa and any prostate cancer (PCa), respectively. Individual authors' definitions for csPCa and PI-RADS thresholds for positive mpMRI were accepted. Detection rates, used as a surrogate of PPV, were pooled using random-effect models. Preplanned subgroup analyses tested PPV after stratification for PI-RADS scores, previous biopsy status, TBx technique, and number of sampled cores. PPV variation over cancer prevalence was evaluated.

EVIDENCE SYNTHESIS

Fifty-six studies, with a total of 16 537 participants, were included in the quantitative synthesis. The PPV of suspicious mpMRI for csPCa was 40% (95% confidence interval 36-43%), with large heterogeneity between studies (I² 94%, p < 0.01). PPV increased according to PCa prevalence. In subgroup analyses, PPVs for csPCa were 13%, 40%, and 69% for, respectively, PI-RADS 3, 4, and 5 (p < 0.001). TBx missed 6%, 6%, and 5% of csPCa in PI-RADS 3, 4, and 5 lesions, respectively. In biopsy-naïve and prior negative biopsy groups, PPVs for csPCa were 42% and 32%, respectively (p = 0.005). Study design, TBx technique, and number of sampled cores did not affect PPV.

CONCLUSIONS

Our meta-analysis underlines that the PPV of mpMRI is strongly dependent on the disease prevalence, and that the main factors affecting PPV are PI-RADS version 2 scores and prior biopsy status. A substantially low PPV for PI-RADS 3 lesions was reported, while it was still suboptimal in PI-RADS 4 and 5 lesions. Lastly, even if the added value of a systematic biopsy for csPCa is relatively low, this rate can improve patient risk assessment and staging.

PATIENT SUMMARY

Targeted biopsy of Prostate Imaging Reporting and Data System 3 lesions should be considered carefully in light of additional individual risk assessment corroborating the presence of clinically significant prostate cancer. On the contrary, the positive predictive value of highly suspicious lesions is not high enough to omit systematic prostate sampling.

Perspective: a critical assessment of PI-RADS 2.1

PURPOSE

In this article we take a critical look at the key changes of the newest edition of the Prostate Imaging Reporting and Data System (PI-RADS) version 2.1 (v2.1) and indicate future directions for further development of the system.

CONCLUSION

PI-RADS v2.1 addresses some of the shortcomings of its widely embraced precursor version 2, largely to simplify interpretation and improve interobserver agreement without changing the fundamental acquisition and scoring guidelines. Biparametric MRI is acknowledged in the newest version, but multiparametric MRI including dynamic contrast-enhanced imaging is still recommended for most scenarios. Management recommendations and guidance on evaluation of follow-up MRI's are still not included in the system.

Association Between Tumor Multifocality on Multi-parametric MRI and Detection of Clinically-Significant Prostate Cancer in Lesions with Prostate Imaging Reporting and Data System (PI-RADS) Score 4

OBJECTIVE

To investigate whether presence of multifocality on multi-parametric magnetic resonance imaging would increase the likelihood of detecting clinically-significant prostate cancer in a PI-RADS 4 lesion.

METHODS

We identified patients with at least 1 PI-RADS 4 lesion who underwent multi-parametric magnetic resonance imaging-ultrasound fusion prostate biopsy. Patients were grouped into 1 of 4 cohorts-cohort 1 (a PI-RADS 4 index lesion and an additional PI-RADS 2 or 3 lesion), cohort 2 (single lesion with PI-RADS 4), cohort 3 (2 or more PI-RADS 4 lesions), or cohort 4 (a PI-RADS 4 lesion and an index lesion with PI-RADS 5). We compared the rate of grade group (GG) ≥ 2 pathology on targeted biopsy of PI-RADS 4 lesions between cohorts and evaluated clinical and radiological factors associated with cancer detection.

RESULTS

The overall rate of GG ≥ 2 pathology in the PI-RADS 4 lesions was 35.2%. The rate of GG ≥ 2 pathology in the cohorts 1, 2, 3, and 4 was 21.7%, 36.3%, 49.1%, and 42.7%, respectively (P< .001). On multivariable analysis, age (OR1.06, P < .001), clinical stage T2 (OR1.59, P= .03), prostate-specific antigen density (OR1.43, P < .001), peripheral zone lesion (OR1.62, P = .04), and study cohort (cohort 2 vs 1, OR1.93, P = .006; and cohort 3 vs 1, OR3.28, P < .001) were significantly associated with the risk of GG ≥ 2 in the PI-RADS 4 lesion.

CONCLUSION

On targeted biopsy of the PI-RADS 4 lesions, the proportion of GG ≥ 2 pathology is approximately 35%. Rate of GG ≥ 2 detection in PI-RADS 4 lesions might differ based on their location, multifocality, and PI-RADS classifications of other lesions identified.