Influence of imaging and histological factors on prostate cancer detection and localisation on multiparametric MRI: a prospective study

The impact of benign tissue within cancerous regions in the prostate: Characterizing sparse and dense prostate cancers on whole-mount histopathology and on multiparametric MRI

PURPOSE

To establish the incidence, size, zonal location and Gleason Score(GS)/Gleason Grade Group(GG) of sparse versus dense prostate cancer (PCa) lesions and to identify the imaging characteristics of sparse versus dense cancers on multiparametric MRI (mpMRI).

METHODS

Seventy-six men with untreated PCa were scanned prior to prostatectomy with endorectal-coil 3 T MRI including T2-weighted imaging, diffusion-weighted imaging and dynamic contrast-enhanced MRI. Cancerous regions were outlined and graded on the whole-mount, processed specimens, with tissue compositions estimated. Regions with cancer comprising <50 % and ≥ 50 % of the tissue were considered sparse and dense respectively. Regions of interest (ROI) were manually drawn on T2-weighted MRI. Within each patient, area-weighted ROI averages were calculated for each imaging measure for each tissue type, GS/GG, and sparse/dense composition.

RESULTS

A large number of cancer regions were identified on histopathology (n = 1193: 939 (peripheral zone (PZ)) and 254 (transition zone (TZ))). Thirty-seven percent of these lesions were sparse. Sparse lesions were primarily low-grade with the majority of PZ and 100 % of TZ sparse lesions ≤GS3 + 3/GG1. Dense lesions were significantly larger than sparse lesions in both PZ and TZ, p < 0.0001. On imaging, 246/45 PZ and 109/8 TZ dense/sparse 2D cancerous ROIs were drawn. Sparse GS3 + 3 and sparse ≥GS3 + 4 cancers did not have significantly different MRI intensities to dense GS3 + 3 cancers, while sparse GS3 + 3/GG1 cancers differed from benign, p < 0.05.

CONCLUSION

Histopathologically identified prostate cancer lesions were sparse in 37 % of cases. Sparse cancers were entirely low grade in TZ and predominantly low-grade in PZ and generally small, thus likely posing lower risk for spread and progression than dense lesions. Sparse lesions were not distinguishable from dense lesions on mpMRI, but could be distinguished from benign tissues.

Strategies for improving image quality in prostate MRI

Prostate magnetic resonance imaging (MRI) stands as the cornerstone in diagnosing prostate cancer (PCa), offering superior detection capabilities while minimizing unnecessary biopsies. Despite its critical role, global disparities in MRI diagnostic performance persist, stemming from variations in image quality and radiologist expertise. This manuscript reviews the challenges and strategies for enhancing image quality in prostate MRI, spanning patient preparation, MRI unit optimization, and radiology team engagement. Quality assurance (QA) and quality control (QC) processes are pivotal, emphasizing standardized protocols, meticulous patient evaluation, MRI unit workflow, and radiology team performance. Additionally, artificial intelligence (AI) advancements offer promising avenues for improving image quality and reducing acquisition times. The Prostate-Imaging Quality (PI-QUAL) scoring system emerges as a valuable tool for assessing MRI image quality. A comprehensive approach addressing technical, procedural, and interpretative aspects is essential to ensure consistent and reliable prostate MRI outcomes.

Navigating the evolving diagnostic and therapeutic landscape of low- and intermediate-risk prostate cancer

ABSTRACT

In this nonsystematic review of the literature, we explored the changing landscape of detection and treatment of low- and intermediate-risk prostate cancer (PCa). Through emphasizing improved cancer assessment with histology classification and genomics, we investigated key developments in PCa detection and risk stratification. The pivotal role of prostate magnetic resonance imaging (MRI) in the novel diagnostic pathway is examined, alongside the benefits and drawbacks of MRI-targeted biopsies for detection and tumor characterization. We also delved into treatment options, particularly active surveillance for intermediate-risk PCa. Outcomes are compared between intermediate- and low-risk patients, offering insights into tailored management. Surgical techniques, including Retzius-sparing surgery, precision prostatectomy, and partial prostatectomy for anterior cancer, are appraised. Each technique has the potential to enhance outcomes and minimize complications. Advancements in technology and radiobiology, including computed tomography (CT)/MRI imaging and positron emission tomography (PET) fusion, allow for precise dose adjustment and daily target monitoring with imaging-guided radiotherapy, opening new ways of tailoring patients' treatments. Finally, experimental therapeutic approaches such as focal therapy open new treatment frontiers, although they create new needs in tumor identification and tracking during and after the procedure.

A novel nomogram to predict clinically significant prostate cancer in MR assisted lesion biopsies: Turkish urooncology association nomogram

OBJECTIVE

This study aimed to develop a novel nomogram to predict clinically significant prostate cancer in patients undergoing multi-parametric prostate MRI-assisted lesion biopsies, addressing the challenges in deciding on biopsy for patients with PI-RADS 3 lesions and follow-up strategies for patients with negative PI-RADS 4 or 5 lesions.

MATERIALS AND METHODS

A retrospective case-control study was conducted using the Turkish Urooncology Association Databases (UROCaD). The final dataset included 2428 lesion biopsy data. Univariate analysis, logistic regression, and validation were performed, with 1942 and 486 lesion biopsy data in the training and validation datasets, respectively.

RESULTS

Age, initial total PSA value, PSA density, prostate volume, lesion length, DRE findings, and PI-RADS score were significantly different between benign or non-significant cancer and clinically significant prostate cancer groups. The developed nomogram incorporated PSA density, age, PI-RADS score, lesion length, and DRE findings. The mean area under the curve for the 6-fold cross-validation was 0.836, while the area under the curve values for the training and validation datasets were 0.827 and 0.861, respectively. The nomogram demonstrated a sensitivity of 75.6% and a specificity of 74.8% at a cut-off score of 24.9, with positive and negative predictive values of 42.2% and 92.6%, respectively.

CONCLUSION

The TUA nomogram, based on PSA density, age, PI-RADS score, lesion length, and DRE findings, provides a reliable and accurate prediction tool for detecting clinically significant prostate cancer in patients undergoing multi-parametric prostate MRI-assisted lesion (fusion) biopsies, potentially improving patient management and reducing unnecessary biopsies.

Is There an Added Value of Quantitative DCE-MRI by Magnetic Resonance Dispersion Imaging for Prostate Cancer Diagnosis?

In this multicenter, retrospective study, we evaluated the added value of magnetic resonance dispersion imaging (MRDI) to standard multiparametric MRI (mpMRI) for PCa detection. The study included 76 patients, including 51 with clinically significant prostate cancer (csPCa), who underwent radical prostatectomy and had an mpMRI including dynamic contrast-enhanced MRI. Two radiologists performed three separate randomized scorings based on mpMRI, MRDI and mpMRI+MRDI. Radical prostatectomy histopathology was used as the reference standard. Imaging and histopathology were both scored according to the Prostate Imaging-Reporting and Data System V2.0 sector map. Sensitivity and specificity for PCa detection were evaluated for mpMRI, MRDI and mpMRI+MRDI. Inter- and intra-observer variability for both radiologists was evaluated using Cohen's Kappa. On a per-patient level, sensitivity for csPCa for radiologist 1 (R1) for mpMRI, MRDI and mpMRI+MRDI was 0.94, 0.82 and 0.94, respectively. For the second radiologist (R2), these were 0.78, 0.94 and 0.96. R1 detected 4% additional csPCa cases using MRDI compared to mpMRI, and R2 detected 20% extra csPCa cases using MRDI. Inter-observer agreement was significant only for MRDI (Cohen's Kappa = 0.4250, p = 0.004). The results of this study show the potential of MRDI to improve inter-observer variability and the detection of csPCa.

Predicting clinically significant prostate cancer following suspicious mpMRI: analyses from a high-volume center

PURPOSE

mpMRI is routinely used to stratify the risk of clinically significant prostate cancer (csPCa) in men with elevated PSA values before biopsy. This study aimed to calculate a multivariable risk model incorporating standard risk factors and mpMRI findings for predicting csPCa on subsequent prostate biopsy.

METHODS

Data from 677 patients undergoing mpMRI ultrasound fusion biopsy of the prostate at the TUM University Hospital tertiary urological center between 2019 and 2023 were analyzed. Patient age at biopsy (67 (median); 33-88 (range) (years)), PSA (7.2; 0.3-439 (ng/ml)), prostate volume (45; 10-300 (ml)), PSA density (0.15; 0.01-8.4), PI-RADS (V.2.0 protocol) score of index lesion (92.2% ≥3), prior negative biopsy (12.9%), suspicious digital rectal examination (31.2%), biopsy cores taken (12; 2-22), and pathological biopsy outcome were analyzed with multivariable logistic regression for independent associations with the detection of csPCa defined as ISUP ≥ 3 (n = 212 (35.2%)) and ISUP ≥ 2 (n = 459 (67.8%) performed on 603 patients with complete information.

RESULTS

Older age (OR: 1.64 for a 10-year increase; p < 0.001), higher PSA density (OR: 1.60 for a doubling; p < 0.001), higher PI-RADS score of the index lesion (OR: 2.35 for an increase of 1; p < 0.001), and a prior negative biopsy (OR: 0.43; p = 0.01) were associated with csPCa.

CONCLUSION

mpMRI findings are the dominant predictor for csPCa on follow-up prostate biopsy. However, PSA density, age, and prior negative biopsy history are independent predictors. They must be considered when discussing the individual risk for csPCa following suspicious mpMRI and may help facilitate the further diagnostical approach.

The Impact of Omitting Contralateral Systematic Biopsy on the Surgical Planning of Patients with a Unilateral Suspicious Lesion on Magnetic Resonance Imaging Undergoing Robot-assisted Radical Prostatectomy for Prostate Cancer

Background and objective

A combined approach of magnetic resonance imaging (MRI)-targeted biopsy (TBx) and bilateral systematic biopsy (SBx) is advised in patients who have an increased risk of prostate cancer (PCa). The diagnostic gain of SBx in detecting PCa for treatment planning of patients undergoing robot-assisted radical prostatectomy (RARP) is unknown. This study aims to determine the impact of omitting contralateral SBx on the surgical planning of patients undergoing RARP in terms of nerve-sparing surgery (NSS) and extended pelvic lymph node dissection (ePLND).

Methods

Case files from 80 men with biopsy-proven PCa were studied. All men had a unilateral suspicious lesion on MRI, and underwent TBx and bilateral SBx. Case files were presented to five urologists for the surgical planning of RARP. Each case file was presented randomly using two different sets of information: (1) results of TBx + bilateral SBx, and (2) results of TBx + ipsilateral SBx. The urologists assessed whether they would perform NSS and/or ePLND.

Key findings and limitations

A change in the surgical plan concerning NSS on the contralateral side was observed in 9.0% (95% confidence interval [CI] 6.4-12.2) of cases. Additionally, the indication for ePLND changed in 5.3% (95% CI 3.3-7.9) of cases. Interobserver agreement based on Fleiss' kappa changed from 0.44 to 0.15 for the indication of NSS and from 0.84 to 0.83 for the indication of ePLND.

Conclusions and clinical implications

In our series, the diagnostic information obtained from contralateral SBx has limited impact on the surgical planning of patients with a unilateral suspicious lesion on MRI scheduled to undergo RARP.

Patient summary

In patients with one-sided prostate cancer on magnetic resonance imaging, omitting biopsies on the other side rarely changed the surgical plan with respect to nerve-sparing surgery and the indication to perform extended lymph node dissection.

Short repetition time diffusion-weighted imaging improves visualization of prostate cancer

PURPOSE

This study aimed to assess whether short repetition time (TR) diffusion-weighted imaging (DWI) could improve diffusion contrast in patients with prostate cancer (PCa) compared with long TR (conventional) reference standard DWI.

MATERIALS AND METHODS

Our Institutional Review Board approved this retrospective study and waived the need for informed consent. Twenty-five patients with suspected PCa underwent multiparametric magnetic resonance imaging (mp-MRI) using a 3.0-T system. DWI was performed with TR of 1850 ms (short) and 6000 ms (long) with b-values of 0, 1000, and 2000s/mm2. Signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR), visual score, apparent diffusion coefficient (ADC), and diagnostic performance were compared between short and long TR DWI for both b-values. The statistical tests included paired t-test for SNR and CNR; Wilcoxon signed-rank test for VA; Pearson's correlation and Bland-Altman plot analysis for ADC; and McNemar test and receiver operating characteristic analysis and Delong test for diagnostic performance.

RESULTS

Regarding b1000, CNR and visual score were significantly higher in short TR compared with long TR (P = .003 and P = .002, respectively), without significant difference in SNR (P = .21). Considering b2000, there was no significant difference in visual score between short and long TR (P = .07). However, SNR and CNR in long TR were higher (P = .01 and P = .04, respectively). ADC showed significant correlations, without apparent bias for ADC between short and long TR for both b-values. For diagnostic performance of DWI between short and long TR for both b-values, one out of five readers noted a significant difference, with the short TR for both b-values demonstrating superior performance.

CONCLUSIONS

Our data showed that the short TR DWI1000 may provide better image quality than did the long TR DWI1000 and may improve visualization and diagnostic performance of PCa for readers.

Prostate Biopsies Can Be Omitted in Most Patients with a Positive Stockholm3 Test and Negative Prostate Magnetic Resonance Imaging

BACKGROUND

Magnetic resonance imaging (MRI) combined with the Stockholm3 test can be used to inform biopsy decision-making in patients with a suspicion of prostate cancer.

OBJECTIVE

To determine the consequence of omitting biopsies in men with a positive Stockholm3 test and a negative MRI.

DESIGN, SETTING, AND PARTICIPANTS

In a real-life setting, 438 men with a positive Stockholm3 test and a negative MRI underwent systematic biopsies from 2017 to 2020.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

The Stockholm3 test result is a percentage risk score with or without a prostate volume cutoff. The main outcomes were the number of clinically significant (Gleason grade group [GG] ≥2) and nonsignificant (GG 1) prostate cancers.

RESULTS AND LIMITATIONS

Median prostate-specific antigen was 4.5 ng/ml (interquartile range 2.8-6.4 ng/ml) and the median age was 69 yr. Systematic biopsies detected grade group (GG) ≥2 disease in 48 men (11%, 95% confidence interval [CI] 8.4-14.2%) and GG 1 disease in 94 men (21.5%, 95% CI 17.9-25.6%). Of 256 patients without a volume cutoff in the test report, GG ≥2 was detected in 37 men (14.5%, 95% CI 10.7-19.3%). Omitting biopsies in patients with a volume cutoff would miss 11 GG ≥2 cases (6%, 95% CI 3.4-10.5%), reduce the number of GG 1 cases detected by 37 (39.4%, 95% CI 30.1-49.5%), and avoid a total of 182 biopsies (41.6%, 95% CI 37.0-46.2%). Limitations include the lack of follow-up data.

CONCLUSIONS

Systematic biopsies can be omitted in patients with a positive Stockholm3 test and a negative MRI when there is a volume cutoff in the test report. With no volume cutoff, biopsies can be considered with shared decision-making.

PATIENT SUMMARY

When investigated on suspicion of prostate cancer with a positive Stockholm3 test and a negative MRI (magnetic resonance imaging), prostate biopsies are only necessary for a subgroup of patients. This can spare some men from undergoing biopsies and reduce the detection of clinically insignificant cancers.

The impact of mpMRI-targeted vs systematic biopsy on the risk of prostate cancer downgrading at final pathology

PURPOSE

Although targeted biopsies (TBx) are associated with improved disease assessment, concerns have been raised regarding the risk of prostate cancer (PCa) overgrading due to more accurate biopsy core deployment in the index lesion.

METHODS

We identified 1672 patients treated with radical prostatectomy (RP) with a positive mpMRI and ISUP ≥ 2 PCa detected via systematic biopsy (SBx) plus TBx. We compared downgrading rates at RP (ISUP 4-5, 3, and 2 at biopsy, to a lower ISUP) for PCa detected via SBx only (group 1), via TBx only (group 2), and eventually for PCa detected with the same ISUP 2-5 at both SBx and TBx (group 3), using multivariable logistic regression models (MVA).

RESULTS

Overall, 12 vs 14 vs 6% (n = 176 vs 227 vs 96) downgrading rates were recorded in group 1 vs group 2 vs group 3, respectively (p < 0.001). At MVA, group 2 was more likely to be downgraded (OR 1.26, p = 0.04), as compared to group 1. Conversely, group 3 was less likely to be downgraded at RP (OR 0.42, p < 0.001).

CONCLUSIONS

Downgrading rates are highest when PCa is present in TBx only and, especially when the highest grade PCa is diagnosed by TBx cores only. Conversely, downgrading rates are lowest when PCa is identified with the same ISUP through both SBx and TBx. The presence of clinically significant disease at SBx + TBx may indicate a more reliable assessment of the disease at the time of biopsy potentially reducing the risk of downgrading at final pathology.

Comparison of Ga-PSMA PET MRI with mpMRI in localization and regional staging of prostate cancer

PURPOSE

To compare diagnostic accuracy in localization and detection of extraprostatic extension (EPE), seminal vesicle invasion (SVI), lymph node involvement (LNI) between PSMA PET MRI and multiparametric MRI (mpMRI) in carcinoma prostate.

METHODS

We did a prospective study of consecutive men with biopsy-proven prostate cancer who underwent radical prostatectomy between July'2020 and Dec'2021 at our institution. Patients underwent PSMA PET MRI imaging. MpMRI findings were inferred separately by another radiologist who was blinded to the PSMA PET findings. PIRADS > 2 and any standardized uptake value (SUV) were considered positive. Findings were mapped to a 30-region anatomical grid and compared with pathology. The uro-pathologist also marked the presence of the tumor onto the same anatomical grid. The presence of EPE, SVI, and LVI was noted.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

The significance in difference: McNemar test. SUVmax and Gleason score: Kruskal-Wallis test.

RESULTS

Seventy-five men (mean age 65) with an average PSA of 21.5 ng/ml were included. The sensitivity of PSMA PET MRI for localization was higher [63.6 vs 41.9] (p < 0.001) while specificity was similar [81.5 vs 83.2] (p 0.103). The former had a higher sensitivity to detect SVI [85.7 vs 57.10] (p = 0.03). No difference in the detection of EPE or LNI was noted. SUVmax > 7 was associated with high-risk disease (Gleason score >/= 7).

LIMITATIONS

non-randomized nature, higher risk population.

CONCLUSION

Ga-PSMA PET MRI improved the localization of prostate cancer and better detection of SVI. Further studies are required. It can act as a single-stop investigation for the primary staging of prostate cancer.

Clinical significance of prostate cancer identified by transperineal standard template biopsy in men with nonsuspicious multiparametric magnetic resonance imaging

OBJECTIVE

Multiparametric magnetic resonance imaging (mpMRI) of the prostate has excellent sensitivity in detecting clinically significant prostate cancer (csCaP). However, whether a negative mpMRI in patients with a clinical suspicion of CaP can omit a confirmatory biopsy remains less understood and without consensus. Transperineal (TP) standard template biopsy (SBx) provides an effective approach to CaP detection. Our aim is to provide a comprehensive understanding of the CaP characteristics detected through TP SBx that are systematically overlooked by mpMRI.

METHODS

We conducted a retrospective analysis of all men who underwent prebiopsy mpMRI and subsequent a 20-core TP SBx at our hospital from September 2019 to February 2021. Patients with suspicious mpMRI received a combined TP SBx and targeted biopsy (TBx) (suspicious group), while those without suspicious (negative) mpMRI and who proceeded to biopsy, received TP SBx only (nonsuspicious group). A negative mpMRI was defined as the absence of suspicious findings and/or the presence of low-risk areas with a PI-RADS score of ≤2. Subsequently, we compared and evaluated the clinical and biopsy characteristics between these 2 groups.

RESULTS

We identified 301 men in suspicious group and 215 men in nonsuspicious group. The overall CaP detection rate and csCaP detection rate by TP SBx were 74.1%, 38.9% for suspicious group and 43.3%, 14.9% for nonsuspicious group, respectively. csCaP NPV of mpMRI was 85.1% with a csCaP prevalence 28.9%. The greatest percentage of cancer involvement (GPC) in biopsy core from nonsuspicious group was significantly lower than those of suspicious group (40% vs. 50%, p = 0.005), In multivariate logistic analysis, only PSAD > 0.15 ng/ml/cc was identified as an independent and significant predictor of csCaP in nonsuspicious group.

CONCLUSION

Within our cohort, false-negative rates of mpMRI for csCaP are substantial, reaching 15%. Nonsuspicious cases may contain a large volume tumor since the high GPC of SBx. For cases with nonsuspicious imaging and higher PSAD, a confirmatory biopsy may be necessary due to the increased risk of missed csCaP by mpMRI.

Utility of Prostate Health Index Density for Biopsy Strategy in Biopsy-Naïve Patients With PI-RADS v2.1 Category 3 Lesions

BACKGROUND

Category 3 lesions in PI-RADSv2.1 pose diagnostic challenges, complicating biopsy decisions. Recent biomarkers like prostate health index (PHI) have shown higher specificity in detecting clinically significant prostate cancer (csPCa) than prostate-specific antigen (PSA). Yet their integration with MRI remains understudied.

PURPOSE

To evaluate the utility of PSA and PHI with its derivatives for detecting csPCa in biopsy-naïve patients with category 3 lesion on initial prostate MRI scan.

STUDY TYPE

Retrospective.

POPULATION

One hundred ninety-three biopsy-naïve patients who underwent MRI, PSA, and PHI testing, followed by both targeted and systematic biopsies.

FIELD STRENGTH/SEQUENCE

Turbo spin-echo T2-weighted imaging, diffusion-weighted single-shot echo-planar imaging, and dynamic contrast-enhanced T1-weighted fast field echo sequence imaging in 3 T.

ASSESSMENT

PHI density (PHID) and PSA density (PSAD) derived by dividing serum PHI and PSA with prostate volume (MRI based methodology suggested by PI-RADSv2.1). Risk-stratified models to evaluate the utility of markers in triaging patients for biopsy, including low-, intermediate-, and high-risk groups.

STATISTICAL TESTS

Independent t-test, Mann-Whitney U test, Mantel-Haenszel test, generalized estimating equation, and receiver operating characteristic (ROC) curve analysis were used. Statistical significance defined as P < 0.05.

RESULTS

CsPCa was found in 16.6% (32/193) of patients. PHID had the highest area under the ROC curve (AUROC) of 0.793, followed by PHI of 0.752, PSAD of 0.750, and PSA of 0.654. PHID with two cut-off points (0.88/mL and 1.82/mL) showed the highest potential biopsy avoidance of 47.7% (92/193) with 5% missing csPCa, and the lowest intermediate-risk group (borderline decision group) at 38.9% (75/193), compared to PSA and PHI.

DATA CONCLUSION

PHID demonstrated better potential in triaging patients with category 3 lesions, possibly aiding more selective and confident biopsy decisions for csPCa detection, than traditional markers.

EVIDENCE LEVEL

4 TECHNICAL EFFICACY: Stage 5.

Characteristics and survival of primary urothelial carcinoma of the prostate: A multi-center retrospective study of 18 cases

OBJECTIVES

To explore the features, treatment, and outcomes of primary urothelial carcinoma of the prostate (PUCP) in a multicenter study.

METHODS

The clinical and imaging features, pathological findings, treatment, and outcomes of patients diagnosed with PUCP from January 2011 to April 2022 at three institutions were collected and analyzed. The Kaplan-Meier method and log-rank test were used to assess survival rates of the overall group and survival differences between groups according to TNM stage.

RESULTS

The study cohort comprised 18 patients with PUCP of mean age 72.4±7.8 years. Dysuria and urinary frequency were the most common symptoms (77.8 %). Sixteen (88.9 %) patients had normal serum total PSA concentrations. Most patients showed abnormalities on urinalysis. MRI was the most accurate diagnostic imaging method (88.9 %). As to immunohistochemistry findings, GATA-3 (81.8 %) and P63 (84.6 %) were positive in most examined patients; however, no lesions were positive for PSA. Three (17.6 %) patients with T1N0M0 and T2N0M0 tumors underwent radical cystectomy. Eleven (64.7 %) patients which almost all had T4 tumors received systematic therapy, most of them receiving chemotherapy with gemcitabine and cisplatin, and radiotherapy. The median overall survival was 42 months, and the median progression-free survival 25 months, the latter being significantly longer in patients with T1-2 than in those with T3-4 disease (p=0.035).

CONCLUSION

PUCP, a rare but highly aggressive type of prostate cancer, should be considered in men with abnormalities on MRI and normal serum PSA concentrations. Positive GATA-3, P63, and negative PSA are typical immunohistochemistry features. Radical cystectomy and systematic therapies can be effective.

Current magnetic resonance imaging-based diagnostic strategies for prostate cancer

Recent developments in multiparametric MRI and MRI-targeted biopsy have made it possible to detect clinically significant cancers more accurately and efficiently than ever before. Furthermore, software that enables easy MRI/US image fusion has been developed and is already available on the market, and this has provided a tailwind for the spread of MRI-based prostate cancer diagnostic strategies. Such precise diagnosis of prostate cancer localization is essential for highly accurate focal therapy. In addition, a recent large-scale study applying MRI to community screening for prostate cancer has reported its usefulness. By contrast, concerns about overdiagnosis and overtreatment, the existence of inter-reader variability in MRI diagnosis, and issues with current MRI-targeted biopsy have emerged. In this article, we review the development of multiparametric MRI and MRI-targeted biopsy to date and the current issues and discuss future directions.

Performance of 18F-DCFPyL PET/CT in Primary Prostate Cancer Diagnosis, Gleason Grading and D'Amico Classification: A Radiomics-Based Study

This study aimed to investigate the performance of 18F-DCFPyL positron emission tomography/computerized tomography (PET/CT) models for predicting benign-vs-malignancy, high pathological grade (Gleason score > 7), and clinical D'Amico classification with machine learning. The study included 138 patients with treatment-naïve prostate cancer presenting positive 18F-DCFPyL scans. The primary lesions were delineated on PET images, followed by the extraction of tumor-to-background-based general and higher-order textural features by applying five different binning approaches. Three layer-machine learning approaches were used to identify relevant in vivo features and patient characteristics and their relative weights for predicting high-risk malignant disease. The weighted features were integrated and implemented to establish individual predictive models for malignancy (Mm), high path-risk lesions (by Gleason score) (Mgs), and high clinical risk disease (by amico) (Mamico). The established models were validated in a Monte Carlo cross-validation scheme. In patients with all primary prostate cancer, the highest areas under the curve for our models were calculated. The performance of established models as revealed by the Monte Carlo cross-validation presenting as the area under the receiver operator characteristic curve (AUC): 0.97 for Mm, AUC: 0.73 for Mgs, AUC: 0.82 for Mamico. Our study demonstrated the clinical potential of 18F-DCFPyL PET/CT radiomics in distinguishing malignant from benign prostate tumors, and high-risk tumors, without biopsy sampling. And in vivo 18F-DCFPyL PET/CT can be considered a noninvasive tool for virtual biopsy for personalized treatment management.

Supplementary Information

The online version contains supplementary material available at 10.1007/s43657-023-00108-y.

Results of fusion prostate biopsy comparing with cognitive and systematic biopsy

PURPOSE

Our study aims to determine whether there are differences in the degree of detection of prostate cancer (PCa) and CsPCa between fusion prostate biopsy (FPB), cognitive biopsy (PCB), and randomized, systematic biopsy (SB).

METHODS

A retrospective analysis was carried out of 195 patients with suspected PCa at the San Cecilio University Clinical Hospital in Granada who underwent a prostate biopsy between January and December 2021. Patients were divided into three groups: group 1, patients undergoing FPB transperineally with ultrasound BK 3000 (N = 87); group 2, PCB (N = 59) transperineally; and group 3, transrectal SB (N = 49), the latter two, with an ultrasound BK Specto.

RESULTS

We found differences in favor of image-directed biopsies (FPB and PCB) with a percentage of positive biopsies of 52.8% and 50%, respectively, compared to 41.4% with SB, but without these differences being significant. Given the controversy in performing prostate biopsies in PI-RADS 3 lesions reported in the literature, a subanalysis was performed excluding the FPB performed for PI-RADS 3 lesions (PI-RADS 4 and 5 are included), finding significant differences when comparing FPB with PCB and SB (group 1, 64% vs group 2, 45.8%; p = 0.05) (group 1, 64% vs group 3, 42.9%; p = 0.035).

CONCLUSION

With the results obtained in our series, we conclude that the finding of a PI-RADS 3 lesion in mpMRI should not be an absolute criterion to indicate prostate biopsy. On the other hand, for PI-RADS 4 and 5 lesions, FPB is recommended, which in this case turns out to be superior to PCB and SB.

Role of preoperative magnetic resonance imaging on the surgical outcomes of radical prostatectomy: Does preoperative tumor recognition reduce the positive surgical margin in a specific location? Experience from a Thailand prostate cancer specialized center

Objective

Multiparametric magnetic resonance imaging (MRI) has become the standard of care for the diagnosis of prostate cancer patients. This study aimed to evaluate the influence of preoperative MRI on the positive surgical margin (PSM) rates.

Methods

We retrospectively reviewed 1070 prostate cancer patients treated with radical prostatectomy (RP) at Siriraj Hospital between January 2013 and September 2019. PSM rates were compared between those with and without preoperative MRI. PSM locations were analyzed.

Results

In total, 322 (30.1%) patients underwent MRI before RP. PSM most frequently occurred at the apex (33.2%), followed by posterior (13.5%), bladder neck (12.7%), anterior (10.7%), posterolateral (9.9%), and lateral (2.3%) positions. In preoperative MRI, PSM was significantly lowered at the posterior surface (9.0% vs. 15.4%, p=0.01) and in the subgroup of urologists with less than 100 RP experiences (32% vs. 51%, odds ratio=0.51, p<0.05). Blood loss was also significantly decreased when a preoperative image was obtained (200 mL vs. 250 mL, p=0.02). Multivariate analysis revealed that only preoperative MRI status was associated with overall PSM and PSM at the prostatic apex. Neither the surgical approach, the neurovascular bundle sparing technique, nor the perioperative blood loss was associated with PSM.

Conclusion

MRI is associated with less overall PSM, PSM at apex, and blood loss during RP. Additionally, preoperative MRI has shown promise in lowering the PSM rate among urologists who are in the early stages of performing RP.

Exploratory analysis of 64 CuCl 2 PET-CT imaging in carcinoma prostate and its comparison with 68 Ga-PSMA-11 and 18 F-FDG PET-CT

AIM

Exploratory analysis of 64 CuCl 2 PET-CT imaging in patients of carcinoma prostate and its head-to-head comparison with 68 Ga-PSMA-11 and 18 F-FDG PET-CT.

METHODS

In this prospective study, 50 patients of biopsy-proven carcinoma prostate belonging to the entire spectrum of disease were evaluated, out of which 21 patients were for initial staging and 29 were for restaging/response evaluation. Both 64 CuCl 2 (early and delayed) and 68 Ga-PSMA-11 PET-CT were undertaken in all patients and 18 F-FDG PET-CT was done in patients whenever possible. All scans were done within a period of 2 weeks, without any interim therapeutic intervention. 64 CuCl 2 PET-CT was acquired at 1 and 3 h. We evaluated the physiological uptake of 64 CuCl 2 , correlated the uptake in primary with disease parameters like Gleason score and serum PSA levels, and compared the detection rates for primary and metastatic disease with 68 Ga-PSMA-11 and 18 F-FDG PET-CT.

RESULTS

The detection rates of primary disease were same for both 64 CuCl 2 and 68 Ga-PSMA-11 PET-CT and both agents performed similarly in detecting extra-prostatic disease. There was no statistically significant correlation observed between the uptake of 64 CuCl 2 in the primary lesion with disease parameters. With regard to the evaluation of metastatic disease, the detection rate of 64 CuCl 2 PET-CT was 86% for lymph nodes, 77.3% for skeletal metastases and 80.6% for soft tissue metastases while 68 Ga-PSMA-11 PET-CT performed better with detection rates were 98%, 99% and 85.4%, respectively. In 17 patients where 18 F-FDG PET-CT was available, 64 CuCl 2 PET-CT detected more metastatic disease than 18 F-FDG PET-CT.

CONCLUSION

64 CuCl 2 PET-CT did not show any additional advantage over 68 Ga-PSMA-11 PET-CT in evaluation of local disease or for the assessment of metastatic disease. When compared to 68 Ga-PSMA-11 PET-CT, the absence of urinary bladder and ureteric activity allows better contrast for evaluating local disease, but it does not translate into increased disease detection.

Characterization of high-grade prostate cancer at multiparametric MRI using a radiomic-based computer-aided diagnosis system as standalone and second reader

PURPOSE

The purpose of this study was to develop and test across various scanners a zone-specific region-of-interest (ROI)-based computer-aided diagnosis system (CAD) aimed at characterizing, on MRI, International Society of Urological Pathology (ISUP) grade≥2 prostate cancers.

MATERIALS AND METHODS

ROI-based quantitative models were selected in multi-vendor training (265 pre-prostatectomy MRIs) and pre-test (112 pre-biopsy MRIs) datasets. The best peripheral and transition zone models were combined and retrospectively assessed in internal (158 pre-biopsy MRIs) and external (104 pre-biopsy MRIs) test datasets. Two radiologists (R1/R2) retrospectively delineated the lesions targeted at biopsy in test datasets. The CAD area under the receiver operating characteristic curve (AUC) for characterizing ISUP≥2 cancers was compared to that of the Prostate Imaging-Reporting and Data System version2 (PI-RADSv2) score prospectively assigned to targeted lesions.

RESULTS

The best models used the 25th apparent diffusion coefficient (ADC) percentile in transition zone and the 2nd ADC percentile and normalized wash-in rate in peripheral zone. The PI-RADSv2 AUCs were 82% (95% confidence interval [CI]: 74-87) and 86% (95% CI: 81-91) in the internal and external test datasets respectively. They were not different from the CAD AUCs obtained with R1 and R2 delineations, in the internal (82% [95% CI: 76-89], P = 0.95 and 85% [95% CI: 78-91], P = 0.55) and external (82% [95% CI: 74-91], P = 0.41 and 86% [95% CI:78-95], P = 0.98) test datasets. The CAD yielded sensitivities of 86-89% and 90-91%, and specificities of 64-65% and 69-75% in the internal and external test datasets respectively.

CONCLUSION

The CAD performance for characterizing ISUP grade≥2 prostate cancers on MRI is not different from that of PI-RADSv2 score across two test datasets.

Comprehensive analysis of predictive factors for upstaging in intraprostatic cancer after radical prostatectomy: Different patterns of spread exist in lesions at different locations

BACKGROUND

Accurate assessment of the clinical staging is crucial for determining the need for radical prostatectomy (RP) in prostate cancer (PCa). However, the current methods for PCa staging may yield incorrect results. This study aimed to comprehensively analyze independent predictors of postoperative upstaging of intraprostatic cancer.

METHODS

We conducted a retrospective analysis of data from intraprostatic cancer patients who underwent radical surgery between March 2019 and December 2022. Intraprostatic cancer was defined as a lesion confined to the prostate, excluding cases where multiparameter magnetic resonance imaging (mpMRI) showed the lesion in contact with the prostatic capsule. We assessed independent predictors of extraprostatic extension (EPE) and analyzed their association with positive surgical margin (PSM) status. In addition, based on the distance of the lesion from the capsule on mpMRI, we divided the patients into non-transition zone and transition zone groups for further analysis.

RESULTS

A total of 500 patients were included in our study. Logistic regression analysis revealed that biopsy Gleason grade group (GG) (odds ratio, OR: 1.370, 95% confidence interval, CI: 1.093-1.718) and perineural invasion (PNI) (OR: 2.746, 95% CI: 1.420-5.309) were predictive factors for postoperative EPE. Both biopsy GG and PNI were associated with lateral (GG: OR: 1.270, 95% CI: 1.074-1.501; PNI: OR: 2.733, 95% CI: 1.521-4.911) and basal (GG: OR: 1.491, 95% CI: 1.194-1.862; PNI: OR: 3.730, 95% CI: 1.929-7.214) PSM but not with apex PSM (GG: OR: 1.176, 95% CI: 0.989-1.399; PNI: OR: 1.204, 95% CI: 0.609-2.381) after RP. Finally, PNI was an independent predictor of EPE in the transition zone (OR: 11.235, 95% CI: 2.779-45.428) but not in the non-transition zone (OR: 1.942, 95% CI: 0.920-4.098).

CONCLUSION

PNI and higher GG may indicate upstaging of tumors in patients with intraprostatic carcinoma. These two factors are associated with PSM in locations other than the apex of the prostate. Importantly, cancer in the transition zone of the prostate is more likely to spread externally through nerve invasion than cancer in the non-transition zone.

Automatic detection of prostate cancer grades and chronic prostatitis in biparametric MRI

BACKGROUND AND OBJECTIVE

With emerging evidence to improve prostate cancer (PCa) screening, multiparametric magnetic prostate imaging is becoming an essential noninvasive component of the diagnostic routine. Computer-aided diagnostic (CAD) tools powered by deep learning can help radiologists interpret multiple volumetric images. In this work, our objective was to examine promising methods recently proposed in the multigrade prostate cancer detection task and to suggest practical considerations regarding model training in this context.

METHODS

We collected 1647 fine-grained biopsy-confirmed findings, including Gleason scores and prostatitis, to form a training dataset. In our experimental framework for lesion detection, all models utilized 3D nnU-Net architecture that accounts for anisotropy in the MRI data. First, we explore an optimal range of b-values for diffusion-weighted imaging (DWI) modality and its effect on the detection of clinically significant prostate cancer (csPCa) and prostatitis using deep learning, as the optimal range is not yet clearly defined in this domain. Next, we propose a simulated multimodal shift as a data augmentation technique to compensate for the multimodal shift present in the data. Third, we study the effect of incorporating the prostatitis class alongside cancer-related findings at three different granularities of the prostate cancer class (coarse, medium, and fine) and its impact on the detection rate of the target csPCa. Furthermore, ordinal and one-hot encoded (OHE) output formulations were tested.

RESULTS

An optimal model configuration with fine class granularity (prostatitis included) and OHE has scored the lesion-wise partial Free-Response Receiver Operating Characteristic (FROC) area under the curve (AUC) of 1.94 (CI 95%: 1.76-2.11) and patient-wise ROC AUC of 0.874 (CI 95%: 0.793-0.938) in the detection of csPCa. Inclusion of the auxiliary prostatitis class has demonstrated a stable relative improvement in specificity at a false positive rate (FPR) of 1.0 per patient, with an increase of 3%, 7%, and 4% for coarse, medium, and fine class granularities.

CONCLUSIONS

This paper examines several configurations for model training in the biparametric MRI setup and proposes optimal value ranges. It also shows that the fine-grained class configuration, including prostatitis, is beneficial for detecting csPCa. The ability to detect prostatitis in all low-risk cancer lesions suggests the potential to improve the quality of the early diagnosis of prostate diseases. It also implies an improved interpretability of the results by the radiologist.

Granulomatous prostatitis after bacille Calmette-Guérin instillation resembles prostate carcinoma: A case report and review of the literature

BACKGROUND

Bacille Calmette-Guérin (BCG) instillation is recommended in patients with non-muscle-invasive bladder cancer who have intermediate-risk and high-risk tumors. However, granulomatous prostatitis is a rare complication induced by BCG instillation, which can easily be misdiagnosed as prostate cancer. Here, we report a case of granulomatous prostatitis that resembled prostate cancer.

CASE SUMMARY

A 64-year-old Chinese man with bladder cancer received BCG instillation. Three days later, he stopped BCG instillation and received anti-infective therapy due to the urinary tract infection. Three months after BCG restart, he had rising total prostate-specific antigen (PSA) (9.14 ng/mL) and decreasing free PSA/total PSA (0.09). T2-weighted images of magnetic resonance imaging (MRI) showed a 28 mm × 20 mm diffuse low signal abnormality in the right peripheral zone, which was markedly hyperintense on high b-value diffusion-weighted MRI and hypointense on apparent diffusion coefficient map images. Considering Prostate Imaging Reporting and Data System score of 5 and possibility of prostate cancer, a prostate biopsy was conducted. Histopathology showed typical features of granulomatous prostatitis. The nucleic acid test for tuberculosis was positive. He was finally diagnosed with BCG-induced granulomatous prostatitis. Thereafter, he stopped BCG instillation and received anti-tuberculosis treatment. During 10 mo follow-up, he had no evidence of tumor recurrence or symptoms of tuberculosis.

CONCLUSION

Temporarily elevated PSA and high followed by low signal abnormality on diffusion-weighted MRI are important indicators of BCG-induced granulomatous prostatitis.

A comprehensive comparison between mpMRI of the prostate, MR-US fusion biopsy and whole mount histopathology

OBJECTIVES

To compare multiparametric magnetic resonance imaging (mpMRI) findings, US-MR fusion prostate biopsy results and whole-mount thin-section histopathology after radical prostatectomy.

PATIENTS AND METHODS

Overall 259 patients, who had undergone mpMRI with lesions reported as PI-RADS 3-5, underwent a MR-US fusion biopsy between 2018 and 2020. Overall 186 biopsies yielded prostate cancer and 104 patients subsequently underwent endoscopic extraperitoneal radical prostatectomy. Histopathology of biopsies was compared to the final histopathology in whole mount thin sections after radical prostatectomy by means of descriptive statistics, and further, the lesions from mpMRT were compared to whole mount histology.

RESULTS

Prostate cancer was diagnosed in 186 (71.8%) of 259 patients (median age 69.2 y, range 42-82 y, median PSA 7.8 ng/ml, range 2.1-31.3 ng/ml). Of those, 95 (51,1%) underwent radical endoscopic prostatectomy, and 80 (43%) chose radiotherapy or active surveillance. In 52/95 (54,7%) with RPE additional lesions were found in the final histological whole mount sections not described at mpMRI. 22/95 (23,2%) of RPE patients had ≥ 1 additional Gleason score ≥ 7 lesions, 23 /259 (8,4%) of biopsies, respectively. The Gleason score after surgery was upgraded in 37/95 (38,9%) and downgraded in 18/95 (18,9%) patients.

CONCLUSION

If we compare all 259 performed biopsies with the final histological whole mount sections which showed additional lesions with Gleason ≥ 7 (23,2%), it can be assumed that up to 10% of clinical significant carcinomas are missed during primary assessment via mpMRI. The majority of additional findings after RP were intermediate/high risk tumors. Upgrades from low-risk to intermediate or high-risk occurred.

Intraobserver and Interobserver Agreement between Six Radiologists Describing mpMRI Features of Prostate Cancer Using a PI-RADS 2.1 Structured Reporting Scheme

Clinical practice has revealed ambiguities in PI-RADS v2.1 scoring, but a limited number of studies are available that validate the interreader and intrareader reproducibility of the mpMRI PI-RADS lexicon. We decomposed the PI-RADS rules into a set of common data elements to evaluate the inter- and intraobserver agreement in assessing the individual features included in the PI-RADS lexicon. Six radiologists (three highly experienced, three less experienced) in two sessions independently read thirty-two lesions in the peripheral and transition zone using the structured reporting tool, blinded to clinical MRI indication. The highest agreement between radiologists was observed for the abnormality detection, the evaluation of the type of signal intensity, and the characteristic of benign prostatic hyperplasia. Moderate agreement was reported for dynamic contrast-enhanced images. This resulted in a decrease in abnormality detection (PA = 76.5%) and enhancement indication (PA = 77.3%). The lowest agreement was observed for highly subjective features: shape, signal intensity level, and type of lesion margins. The results indicate the limitations of the PI-RADS v2.1 lexicon in relation to interreader and intrareader reproducibility. We have demonstrated that it is possible to develop structured reporting systems standardized according to the PI-RADS lexicon.

Intermediate-risk Prostate Cancer-A Sheep in Wolf's Clothing?

This case-based discussion describes a 65-year-old man newly diagnosed with International Society of Urological Pathology (ISUP) grade 2 prostate cancer (PCa). According to the European Association of Urology classification system, the patient harbors an intermediate-risk cancer. In step-by step discussion, we elaborate guideline-based treatment modalities for intermediate-risk PCa focused on debating active surveillance versus active treatment. Thereby, we discuss the importance of patient characteristics, including age, hereditary factors, life expectancy and comorbidity status, findings of multiparametric magnetic resonance imaging, as well as prostate-specific antigen (PSA) density and PSA kinetics, in predicting the clinical course of the disease. In addition, we focus on cribriform pathology as a predictor of adverse outcomes and critically discuss its relevance in patient management. Lastly, we outline genomic stratification in ISUP 2 cancer as a future tool to predict PCa aggressiveness. PATIENT SUMMARY: Based on current guidelines, patients with intermediate-risk prostate cancer are treated actively or can alternatively undergo an active surveillance approach when favorable risk factors are present. One major issue is to discriminate between patients who benefit from an active therapy approach and those who benefit from a deferred treatment. Therefore, reliable biomarkers and early predictors of disease progression are needed urgently.

The role of the size and number of index lesion in the diagnosis of clinically significant prostate cancer in patients with PI-RADS 4 lesions who underwent in-bore MRI-guided prostate biopsy

PURPOSE

To evaluate the contribution of the size and number of the sampled lesions to the diagnosis of clinically significant prostate cancer (CSPC) in patients who had PI-RADS 4 lesions.

METHODS

In this retrospective study, a total of 159 patients who had PI-RADS 4 lesions and underwent In-bore MRI-Guided prostate biopsy were included. Patients with a lesion classified as Grade Group 2 and above were considered to have CSPC. Univariate and multivariate regression analyses were used to evaluate the factors affecting the diagnosis of prostate cancer (PCa) and CSPC.

RESULTS

A great majority (86.8%) of the patients were biopsy-naïve. About three-fourths (71.7%) had PCa, and half (54.1%) had CSPC. When the patients were divided into three groups according to the index lesion size (< 5 mm, 5-10 mm, and > 10 mm), the prevalence of PCa was 64.3, 67.5, and 82.4% and the prevalence of CSPC was 42.9, 51.2, and 64.7%, respectively. In multivariate analysis, age, index lesion size, prostate volume (< 50 ml) and being biopsy-naïve were found significant for PCa, while age and prostate volume (< 50 ml) were significant for CSPC.

CONCLUSION

The number of lesions was found to be insignificant in predicting PCa and CSPC. While the size of PI-RADS 4 lesions was significant in predicting PCa, it had no significance in detecting CSPC.

Imaging Recommendations for Diagnosis, Staging, and Management of Prostate Cancer

The Prostate Carcinoma Guidelines Panel have formulated these guidelines to assist medical professionals in the evidence-based management of prostate cancer. These have been formulated by a panel consisting of Indian multidisciplinary group of radiologists, uro-oncologists, urologists, radiation oncologists, medical oncologists, and pathologists. These recommendations present the best evidence available to the clinicians; however, using these recommendations will not always result in the best outcome. They aid in decision making for individual patients; however, these will never replace clinical expertise when making treatment decisions. Taking personal values and preferences or individual circumstances of patients into account is necessary for final treatment decision. Guidelines are not mandatory and should not to be referred as a legal standard of care.

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

PURPOSE

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

METHODS

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

RESULTS

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

CONCLUSION

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

The Diagnostic Value of PI-RADS v2.1 in Patients with a History of Transurethral Resection of the Prostate (TURP)

To explore the diagnostic value of the Prostate Imaging−Reporting and Data System version 2.1 (PI-RADS v2.1) for clinically significant prostate cancer (CSPCa) in patients with a history of transurethral resection of the prostate (TURP), we conducted a retrospective study of 102 patients who underwent systematic prostate biopsies with TURP history. ROC analyses and logistic regression analyses were performed to demonstrate the diagnostic value of PI-RADS v2.1 and other clinical characteristics, including PSA and free/total PSA (F/T PSA). Of 102 patients, 43 were diagnosed with CSPCa. In ROC analysis, PSA, F/T PSA, and PI-RADS v2.1 demonstrated significant diagnostic value in detecting CSPCa in our cohort (AUC 0.710 (95%CI 0.608−0.812), AUC 0.768 (95%CI 0.676−0.860), AUC 0.777 (95%CI 0.688−0.867), respectively). Further, PI-RADS v2.1 scores of the peripheral and transitional zones were analyzed separately. In ROC analysis, PI-RADS v2.1 remained valuable in identifying peripheral-zone CSPCa (AUC 0.780 (95%CI 0.665−0.854; p < 0.001)) while having limited capability in distinguishing transitional zone lesions (AUC 0.533 (95%CI 0.410−0.557; p = 0.594)). PSA and F/T PSA retain significant diagnostic value for CSPCa in patients with TURP history. PI-RADS v2.1 is reliable for detecting peripheral-zone CSPCa but has limited diagnostic value when assessing transitional zone lesions.

Active surveillance protocol in prostate cancer in Portugal

OBJECTIVE

To examine clinical practice patterns in locally managing patients under an active surveillance protocol among Portuguese urologists.

INTRODUCTION

Prostate cancer (PCa) is a heterogeneous disease with many prostate adenocarcinomas being indolent and a low probability of ever causing symptoms or death. Active surveillance (AS) is a form of conservative management aimed to reduce over-treatment for low-risk PCa patients. Over the years, experience with AS has grown considerably and is now standard in some countries, however a universal protocol still does not exist.

METHODS

Nationwide anonymous e-survey concerning habits and practices on AS among Portuguese urologists, that consisted of twelve questions and was sent electronically to all 368 current members of the Portuguese Urological Association.

RESULTS

56 urologists were surveyed (15.21% answer rate), evenly distributed geographically and allocated according to years of experience as well as number of PCa patients managed monthly. The vast majority of respondents recommends AS to their patients, particularly ISUP grade 1 patients, whose PSA serum level is bellow 20 ng/mL. Observance of AS programs by patients was not in question but concerns exist over psychological morbidity while harboring disease. Majority believed that international guidelines surveillance protocols were adequate and sufficient, but there are some constraints concerning availability of periodic MRIs and re-biopsy needs.

CONCLUSIONS

AS seems to be sustained in urologist clinical practice, although patients still lag to adhere and choose for active treatment. AS may not be an easy choice for patients and clinicians due to uncertainty of disease progression, risk of loss to follow-up and repeated biopsies but is also a cause for anxiety, depression, uncertainty and a perception of danger.

Diagnostic Performance of Prostate-specific Membrane Antigen Positron Emission Tomography-targeted biopsy for Detection of Clinically Significant Prostate Cancer: A Systematic Review and Meta-analysis

CONTEXT

Prostate-specific membrane antigen positron emission tomography (PSMA-PET) has gained acceptance as a staging tool for prostate cancer (PCa). Recent reports suggest an association between PSMA PET and detection of clinically significant PCa (csPCa) on prostate biopsy.

OBJECTIVE

To assess the diagnostic accuracy of PSMA PET-targeted biopsy (PSMA-PET-TB) for csPCa detection.

EVIDENCE ACQUISITION

We searched PubMed, Web of Science, and Scopus in December 2021 to identify studies assessing the accuracy of PSMA-PET-TB for csPCa detection. A diagnostic meta-analysis was performed to calculate pooled sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of PSMA-PET-TB alone and in combination with magnetic resonance imaging (MRI)-TB for detecting csPCa.

EVIDENCE SYNTHESIS

Overall, five prospective studies involving 497 patients were eligible for this meta-analysis. For csPCa detection, PSMA-PET-TB had pooled sensitivity, specificity, PPV, and NPV of 0.89 (95% confidence interval [CI] 0.85-0.93), 0.56 (95% CI 0.29-0.80), 0.69 (95% CI 0.58-0.79), and 0.78 (95% CI 0.50-0.93), respectively. Among the three studies assessing the PSMA-PET + MRI-TB strategy, the pooled sensitivity, specificity, PPV, and NPV for csPCa detection were 0.91 (95% CI 0.77-0.97), 0.64 (95% CI 0.40-0.82), 0.75 (95% CI 0.56-0.87), and 0.85 (95% CI 0.62-0.95), respectively. For lesions with a Prostate Imaging-Reporting and Data System (PI-RADS) score of 3, the sensitivity, specificity, PPV, and NPV were 0.69, 0.73, 0.48, and 0.86, respectively.

CONCLUSIONS

PSMA-PET-TB appears to have favorable diagnostic accuracy for csPCa detection and combination with MRI seems to improve this. According to our meta-analysis, PSMA-PET has promising clinical application for detection of csPCa, namely in the case of PI-RADS 3 lesions. Further prospective studies are needed to explore the true clinical utility of a PSMA-PET-based diagnostic pathway.

PATIENT SUMMARY

Prostate-specific membrane antigen positron emission tomography (PSMA-PET) is a promising imaging method for detecting clinically significant prostate cancer and seems to have additional value to magnetic resonance imaging (MRI) for detection.

Update of PSMA Theranostics in Prostate Cancer: Current Applications and Future Trends

There is now an increasing trend for targeting cancers to go beyond early diagnosis and actually improve Progression-Free Survival and Overall Survival. Identifying patients who might benefit from a particular targeted treatment is the main focus for Precision Medicine. Radiolabeled ligands can be used as predictive biomarkers which can confirm target expression by cancers using positron emission tomography (PET). The same ligand can subsequently be labeled with a therapeutic radionuclide for targeted radionuclide therapy. This combined approach is termed “Theranostics”. The prostate-specific membrane antigen (PSMA) has emerged as an attractive diagnostic and therapeutic target for small molecule ligands in prostate cancer. It can be labeled with either positron emitters for PET-based imaging or beta and alpha emitters for targeted radionuclide therapy. This review article summarizes the important concepts for Precision Medicine contributing to improved diagnosis and targeted therapy of patients with prostate cancer and we identify some key learning points and areas for further research.

Artificial intelligence trained with integration of multiparametric MR-US imaging data and fusion biopsy trajectory-proven pathology data for 3D prediction of prostate cancer: A proof-of-concept study

BACKGROUND

We aimed to develop an artificial intelligence (AI) algorithm that predicts the volume and location of clinically significant cancer (CSCa) using convolutional neural network (CNN) trained with integration of multiparametric MR-US image data and MRI-US fusion prostate biopsy (MRI-US PBx) trajectory-proven pathology data.

METHODS

Twenty consecutive patients prospectively underwent MRI-US PBx, followed by robot-assisted radical prostatectomy (RARP). The AI algorithm was trained with the integration of MR-US image data with a MRI-US PBx trajectory-proven pathology. The relationship with the 3D-cancer-mapping of RARP specimens was compared between AI system-suggested 3D-CSCa mapping and an experienced radiologist's suggested 3D-CSCa mapping on MRI alone according to the Prostate Imaging Reporting and Data System (PI-RADS) version 2. The characteristics of detected and undetected tumors at AI were compared in 22,968 image data. The relationships between CSCa volumes and volumes predicted by AI as well as the radiologist's reading based on PI-RADS were analyzed.

RESULTS

The concordance of the CSCa center with that in RARP specimens was significantly higher in the AI prediction than the radiologist' reading (83% vs. 54%, p = 0.036). CSCa volumes predicted with AI were more accurate (r = 0.90, p < 0.001) than the radiologist's reading. The limitations include that the elastic fusion technology has its own registration error.

CONCLUSIONS

We presented a novel pilot AI algorithm for 3D prediction of PCa. AI was trained by integration of multiparametric MR-US image data and fusion biopsy trajectory-proven pathology data. This deep learning AI model may more precisely predict the 3D mapping of CSCa in its volume and center location than a radiologist's reading based on PI-RADS version 2, and has potential in the planning of focal therapy.

Evaluating the diagnostic role of in-bore magnetic resonance imaging guided prostate biopsy: a single-centre study

Background

To evaluate the role of in‐bore MRI‐guided biopsy (IB‐MRGB) in the diagnosis of clinically significant prostate cancer (csPCa).

Methods

In this tertiary single centre study, a total of 125 consecutive patients receiving IB‐MRGB over a three‐year period were evaluated, including 73 patients who had prior biopsies and 52 biopsy‐naïve patients. We assessed cancer detection rate of patients according to the degree of suspicion based on mpMRI findings. Histopathological data were reviewed by experienced uropathologists.

Results

The mpMRI was suspicious for PCa (PI‐RADS 4/5) in 77% (96/125) and equivocal (PI‐RADS 3) in 23% (29/125). The detection rate for csPCa was 54.2% (52/96) and 20.7% (6/29) for suspicious lesions (PI‐RADS 4/5) and equivocal lesions (PI‐RADS 3), respectively. In subgroup analysis, patients with previous negative biopsy, overall positive biopsy rate and csPCa detection rate were 48.3% (19/35) and 34.5% (13/35), respectively. In patients on AS, 36/44 (81.8%) and 21/44 (47.8%) had PCa and csPCa respectively. In biopsy‐naïve patients 34/52 (65.4%) and 27/52 (51.92%) had PCa and csPCa respectively. Of the patients on AS, 18/44 (41.6%) upgraded from ISUP 1 to ISUP 2 PCa, and 4/44 (9.1%) upgraded from ISUP 1 to ISUP 3 PCa on IB‐MRGB. A total of 14 Clavien‐Dindo≤2 complications occurred in 14 patients (11.2%) that were directly related to the biopsy. No Clavien‐Dindo≥3 complications occurred.

Conclusion

MRI‐targeted biopsy is suitable for assessment of csPCa. Given the favourable complications profile, its use may be considered in both the initial biopsy and re‐biopsy settings.

The current role of MRI for guiding active surveillance in prostate cancer

Active surveillance (AS) is the recommended treatment option for low-risk and favourable intermediate-risk prostate cancer management, preserving oncological and functional outcomes. However, active monitoring using relevant parameters in addition to the usual clinical, biological and pathological considerations is necessary to compensate for initial undergrading of the tumour or to detect early progression without missing the opportunity to provide curative therapy. Indeed, several studies have raised concerns about inadequate biopsy sampling at diagnosis. However, the implementation of baseline MRI and targeted biopsy have led to improved initial stratification of low-risk disease; baseline MRI correlates well with disease characteristics and AS outcomes. The use of follow-up MRI during the surveillance phase also raises the question of the requirement for serial biopsies in the absence of radiological progression and the possibility of using completely MRI-based surveillance, with triggers for biopsies based solely on MRI findings. This concept of a tailored-risk, imaging-based monitoring strategy is aimed at reducing invasive procedures. However, the abandonment of serial biopsies in the absence of MRI progression can probably not yet be recommended in routine practice, as the data from real-life cohorts are heterogeneous and inconclusive. Thus, the evolution towards a routine, fully MRI-guided AS pathway has to be preceded by ensuring quality programme assessment for MRI reading and by demonstrating its safety in prospective trials.

Impact of mpMRI targeted biopsy on intraoperative nerve-sparing (NeuroSAFE) during robot-assisted laparoscopic radical prostatectomy

BACKGROUND

The aim of our study was to evaluate the impact of prostate biopsy technique (transrectal ultrasound (US)-prostate biopsy (PBx) versus multiparametric magnetic resonance imaging (mpMRI) targeted prostate biopsy (MRI-PBx) on intraoperative nerve-sparing and the rate of secondary neurovascular-bundle resection (SNR) in patients undergoing robot-assisted laparoscopic radical prostatectomy (RARP). A real-time investigation with a frozen-section examination (NeuroSAFE) microscopically excluded or confirmed prostate cancer invasion of the nerve structures resulting in preservation of the neurovascular bundle or SNR. Additionally, we analyzed risk factors related to SNR, such as longer operation time and postoperative complications.

METHODS

The total study cohort was stratified according to non-nerve-sparing versus nerve-sparing RARP. Patients with nerve-sparing approach were then stratified according to biopsy technique (PBx vs. MRI-PBx). Further, we compared PBx versus MRI-PBx according to SNR rate.

RESULTS

We included a total of 470 consecutive patients, who underwent RARP for PCa at our institution between January 2016 and December 2019. Patients with a preoperative MRI-PBx had a 2.12-fold higher chance of successful nerve-sparing (without SNR) compared to patients with PBx (p < 0.01). Patients with preoperative MRI-PBx required 73% less intraoperative SNR compared to patients with PBx (p < 0.0001). Prior MRI-PBx is thus a predictor for successful nerve-sparing RARP approach.

CONCLUSION

Preoperative MRI-PBx led to better oncological outcomes and less SNR. Young patients with good erectile function could benefit from a preoperative MRI-PBx before nerve-sparing RARP.

Comparison of transperineal and transrectal targeted prostate biopsy using Mahalanobis distance matching within propensity score caliper method: A multicenter study of Turkish Urooncology Association

OBJECTIVE

To compare the clinically significant prostate cancer (csPC)-detecting results of transperineal and transrectal targeted biopsy (TPTB and TRTB, respectively) by performing matching analysis.

PATIENTS AND METHODS

This study has used the PC and prostate biopsy database from the Turkish Urooncology Association. A total of 1143 patients with Prostate Imaging-Reporting and Data System (PI-RADS) with ≥3 lesions on multiparametric magnetic resonance imaging (mpMRI) and who had received a software-guided transperineal/transrectal MRI/transrectal ultrasound (TRUS) fusion prostate biopsy with concomitant standard systematic 12-core biopsy were included in this study. csPC detection rates of the TP and TR approaches were compared following Mahalanobis distance matching within propensity score caliper method. The following four variables were selected as covariates for the matching procedure: age, digital rectal examination findings, PSA density, and the index lesion PI-RADS score.

RESULTS

The matched sample included 508 TR and 276 TP patients. In both the TP and the TR groups, targeted biopsy was superior to systematic biopsy in detecting csPC (27.5% vs. 24.6%, p < 0.001 and 19.5% vs. 16.3%, p < 0.0001, respectively). Both TPTB and TP systematic biopsy was found to be superior to TRTB and TR systematic biopsy in terms of csPC detection (27.5% vs. 19.5%, p = 0.012 and 24.6% vs. 16.3%, p = 0.006). In patients with an anterior index lesion, an apical index lesion, and a larger prostate, the superiority of TPTB to TRTB was found to be more prominent in terms of csPC detection (37.8% vs. 18.3%, p = 0.044; 34.6% vs. 14.7%, p = 0.002; and 25% vs. 5.1%, p = 0.033, respectively).

CONCLUSION

Targeted biopsy was found to be superior to systematic biopsy in detecting csPC in both the TP and the TR approaches. The TP approach is preferred because of its clear superiority in detecting csPC in targeted biopsy, especially in patients with anterior and apical lesions and with larger prostates.

Tumour growth rates of prostate cancer during active surveillance: is there a difference between MRI-visible low and intermediate-risk disease?

OBJECTIVES

The aim of this study was to evaluate the changes in lesion volume on serial multiparametric magnetic resonance (mpMRI) during active surveillance for prostate cancer.

METHODS

A total of 160 patients with a targeted biopsy-confirmed visible lesion on mpMRI, stratified by low- and intermediate-risk disease (Gleason Grade Group 1 vs Gleason Grade Group 2), were analysed. The % change per year was calculated using the formula: [(final volume/initial volume) exp (1/interval between scans in years)]-1.

RESULTS

There was no significant difference in the annual median percentage change between Gleason Grade Group 1 (18%) and Gleason Grade Group 2 (23%) disease (p = 0.16), and between ≤ 10% (23%) and > 10% (22%) of Gleason pattern 4 (p = 0.78).Assuming a spherical lesion, these changes corresponded to annual increases in mean tumour diameter of 6% and 7% for Gleason Grade Group 1 and Gleason Grade Group 2 respectively, which may be less than the interscan variability of serial mpMRI.

CONCLUSION

In an active surveillance cohort, we did not see a significant difference in the annual growth rate of Gleason Grade Group 1 and 2 tumours.

ADVANCES IN KNOWLEDGE

In patients on active surveillance, the measured growth rates for visible tumours in Gleason Grade Groups 1 and 2 were similar. The annual growth rate was small in most cases and this may have implications for the MRI follow-up interval in active surveillance.

Combined model-based and deep learning-based automated 3D zonal segmentation of the prostate on T2-weighted MR images: clinical evaluation

OBJECTIVE

To train and to test for prostate zonal segmentation an existing algorithm already trained for whole-gland segmentation.

METHODS

The algorithm, combining model-based and deep learning-based approaches, was trained for zonal segmentation using the NCI-ISBI-2013 dataset and 70 T2-weighted datasets acquired at an academic centre. Test datasets were randomly selected among examinations performed at this centre on one of two scanners (General Electric, 1.5 T; Philips, 3 T) not used for training. Automated segmentations were corrected by two independent radiologists. When segmentation was initiated outside the prostate, images were cropped and segmentation repeated. Factors influencing the algorithm's mean Dice similarity coefficient (DSC) and its precision were assessed using beta regression.

RESULTS

Eighty-two test datasets were selected; one was excluded. In 13/81 datasets, segmentation started outside the prostate, but zonal segmentation was possible after image cropping. Depending on the radiologist chosen as reference, algorithm's median DSCs were 96.4/97.4%, 91.8/93.0% and 79.9/89.6% for whole-gland, central gland and anterior fibromuscular stroma (AFMS) segmentations, respectively. DSCs comparing radiologists' delineations were 95.8%, 93.6% and 81.7%, respectively. For all segmentation tasks, the scanner used for imaging significantly influenced the mean DSC and its precision, and the mean DSC was significantly lower in cases with initial segmentation outside the prostate. For central gland segmentation, the mean DSC was also significantly lower in larger prostates. The radiologist chosen as reference had no significant impact, except for AFMS segmentation.

CONCLUSIONS

The algorithm performance fell within the range of inter-reader variability but remained significantly impacted by the scanner used for imaging.

KEY POINTS

• Median Dice similarity coefficients obtained by the algorithm fell within human inter-reader variability for the three segmentation tasks (whole gland, central gland, anterior fibromuscular stroma). • The scanner used for imaging significantly impacted the performance of the automated segmentation for the three segmentation tasks. • The performance of the automated segmentation of the anterior fibromuscular stroma was highly variable across patients and showed also high variability across the two radiologists.

Relationship of prostate cancer topography and tumour conspicuity on multiparametric magnetic resonance imaging: a protocol for a systematic review and meta-analysis

INTRODUCTION

Multiparametric magnetic resonance imaging (mpMRI) has improved the triage of men with suspected prostate cancer, through precision prebiopsy identification of clinically significant disease. While multiple important characteristics, including tumour grade and size have been shown to affect conspicuity on mpMRI, tumour location and association with mpMRI visibility is an underexplored facet of this field. Therefore, the objective of this systematic review and meta-analysis is to collate the extant evidence comparing MRI performance between different locations within the prostate in men with existing or suspected prostate cancer. This review will help clarify mechanisms that underpin whether a tumour is visible, and the prognostic implications of our findings.

METHODS AND ANALYSIS

The databases MEDLINE, PubMed, Embase and Cochrane will be systematically searched for relevant studies. Eligible studies will be full-text English-language articles that examine the effect of zonal location on mpMRI conspicuity. Two reviewers will perform study selection, data extraction and quality assessment. A third reviewer will be involved if consensus is not achieved. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines will inform the methodology and reporting of the review. Study bias will be assessed using a modified Newcastle-Ottawa scale. A thematic approach will be used to synthesise key location-based factors associated with mpMRI conspicuity. A meta-analysis will be conducted to form a pooled value of the sensitivity and specificity of mpMRI at different tumour locations.

ETHICS AND DISSEMINATION

Ethical approval is not required as it is a protocol for a systematic review. Findings will be disseminated through peer-reviewed publications and conference presentations.

PROSPERO REGISTRATION NUMBER

CRD42021228087.

The best prostate biopsy sampling system-fusion and systematic biopsy: A single center experience

BACKGROUND

Prostate cancer is the second most commonly diagnosed cancer in men. The diagnostic accuracy in prostate cancer can be increased by employing a preliminary multiparametric MRI followed by a fusion-targeted biopsy.

METHODS

To compare the diagnostic accuracy of fusion-targeted biopsy with the standard systematic biopsy in prostate cancer patients, we enrolled 139 patients on which we performed 139 prostate biopsies consisting of three targeted samples followed by 12 regular systematic samples. Based on histology, we analyzed the diagnostic performance of the two methods.

RESULTS

Both methods were equally good at detecting clinically significant cancer (83.3%, 50/60), while systematic biopsy detected more clinically insignificant cancers. However, the best diagnostic performance is obtained by combining the two methods.

CONCLUSION

The two methods are best seen as synergistic, and the addition of fusion biopsy can be used to detect more clinically significant prostate cancers than systematic biopsy alone.

Acute and subacute prostate MRI findings after MRI-guided transurethral ultrasound ablation of prostate cancer

BACKGROUND

Magnetic resonance imaging (MRI)-guided transurethral ultrasound ablation (TULSA) is an emerging method for treatment of localized prostate cancer (PCa). TULSA-related subacute MRI findings have not been previously characterized.

PURPOSE

To evaluate acute and subacute MRI findings after TULSA treatment in a treat-and-resect setting.

MATERIAL AND METHODS

Six men with newly diagnosed MRI-visible and biopsy-concordant clinically significant PCa were enrolled and completed the study. Eight lesions classified as PI-RADS 3-5 were focally ablated using TULSA. One- and three-week follow-up MRI scans were performed between TULSA and robot-assisted laparoscopic prostatectomy.

RESULTS

TULSA-related hemorrhage was detected as a subtle T1 hyperintensity and more apparent T2 hypointensity in the MRI. Both prostate volume and non-perfused volume (NPV) markedly increased after TULSA at one week and three weeks after treatment, respectively. Lesion apparent diffusion coefficient values increased one week after treatment and decreased nearing the baseline values at the three-week MRI follow-up.

CONCLUSION

The optimal timing of MRI follow-up seems to be at the earliest at three weeks after treatment, when the post-procedural edema has decreased and the NPV has matured. Diffusion-weighted imaging has little or no added diagnostic value in the subacute setting.

Magnetic Resonance Imaging/Ultrasound Fusion-guided Transperineal Versus Magnetic Resonance Imaging/Ultrasound Fusion-guided Transrectal Prostate Biopsy-A Systematic Review

CONTEXT

Magnetic resonance imaging (MRI)-targeted biopsies have changed the dogma in prostate cancer diagnosis. Biopsies can be performed either transrectally (MRI-guided and transrectal ultrasound fusion transrectal biopsy [MRI-TRUSB]) or transperineally (MRI-guided and transrectal ultrasound fusion transperineal biopsy [MRI-TPB]).

OBJECTIVE

To evaluate the detection and complication rates of MRI-TRUSB and MRI-TPB.

EVIDENCE ACQUISITION

We performed a literature search in PubMed, Scopus, EMBASE, and CENTRAL, and selected randomized controlled trials (RCTs) and observational studies comparing MRI-TRUSB versus MRI-TPB.

EVIDENCE SYNTHESIS

Our search identified 3608 studies; we included five in the qualitative and two in the quantitative synthesis. On per-patient pooled analysis for clinically significant prostate cancer (csPCa), MRI-TPB detection rates were significantly higher (relative risk 1.28 [95% confidence interval {CI} 1.03-1.60], p =  0.03). On a per-lesion analysis, MRI-TPB anterior csPCa detection rates were statistically significantly higher (relative risk 2.46 [95% CI 1.22-4.98], p =  0.01). On a per-lesion analysis, MRI-TPB and MRI-TRUSB overall cancer detection rates were 75% and 81.6% (p= 0.53), and csPCa detection rates were 65.7% and 75.5% (p =  0.40), respectively. MRI-TPB had lower complication rates (odds ratio 2.56 [95% CI 1.14-5.56, p <  0.05]). On Grading of Recommendations Assessment, Development, and Evaluation (GRADE) evaluation, we rated all outcomes as "very low" certainty of the evidence for all outcome measures.

CONCLUSIONS

This review highlights the paucity of good-quality evidence comparing MRI-TPB and MRI-TRUSB. MRI-TPB achieves better detection for csPCa, anterior tumors, and lower infective complications. While RCTs are the highest quality of evidence that can address existing evidence limitations, there are concerns regarding infective complications associated with the MRI-TRUSB. Therefore, the authors propose that researchers and clinicians adopt a pragmatic approach by maintaining prospective databases, internal auditing of the MRI-TPB approach, and comparing these data with historical MRI-TRUSB cohorts.

PATIENT SUMMARY

We looked at the outcomes by comparing magnetic resonance imaging (MRI)-guided and transrectal ultrasound fusion transrectal biopsy with MRI-guided and transrectal ultrasound fusion transperineal biopsy (TPB). The analysis suggests, based on very low certainty evidence, that MRI-TPB has better detection for clinically significant prostate cancer, anterior tumors, and lower complications.

Developing Strategy to Predict the Results of Prostate Multiparametric Magnetic Resonance Imaging and Reduce Unnecessary Multiparametric Magnetic Resonance Imaging Scan

Purpose

The clinical utility of multiparametric magnetic resonance imaging (mpMRI) for the detection and localization of prostate cancer (PCa) has been evaluated and validated. However, the implementation of mpMRI into the clinical practice remains some burden of cost and availability for patients and society. We aimed to predict the results of prostate mpMRI using the clinical parameters and multivariable model to reduce unnecessary mpMRI scans.

Methods

We retrospectively identified 784 men who underwent mpMRI scans and subsequent prostate biopsy between 2016 and 2020 according to the inclusion criterion. The cohort was split into a training cohort of 548 (70%) patients and a validation cohort of 236 (30%) patients. Clinical parameters including age, prostate-specific antigen (PSA) derivates, and prostate volume (PV) were assessed as the predictors of mpMRI results. The mpMRI results were divided into groups according to the reports: “negative”, “equivocal”, and “suspicious” for the presence of PCa.

Results

Univariate analysis showed that the total PSA (tPSA), free PSA (fPSA), PV, and PSA density (PSAD) were significant predictors for suspicious mpMRI (P < 0.05). The PSAD (AUC = 0.77) and tPSA (AUC = 0.74) outperformed fPSA (AUC = 0.68) and PV (AUC = 0.62) in the prediction of the mpMRI results. The multivariate model (AUC = 0.80) had a similar diagnostic accuracy with PSAD (P = 0.108), while higher than tPSA (P = 0.024) in predicting the mpMRI results. The multivariate model illustrated a better calibration and substantial improvement in the decision curve analysis (DCA) at a threshold above 20%. Using the PSAD with a 0.13 ng/ml² cut-off could spare the number of mpMRI scans by 20%, keeping a 90% sensitivity in the prediction of suspicious MRI-PCa and missing three (3/73, 4%) clinically significant PCa cases. At the same sensitivity level, the multivariate model with a 32% cut-off could spare the number of mpMRI scans by 27%, missing only one (1/73, 1%) clinically significant PCa case.

Conclusion

Our multivariate model could reduce the number of unnecessary mpMRI scans without comprising the diagnostic ability of clinically significant PCa. Further prospective validation is required.

Biomarker in Active Surveillance for Prostate Cancer: A Systematic Review

Active surveillance (AS) in prostate cancer (PCa) represents a curative alternative for men with localised low-risk PCa. Continuous improvement of AS patient's selection and surveillance modalities aims at reducing misclassification, simplifying modalities of surveillance and decreasing need for invasive procedures such repeated biopsies. Biomarkers represent interesting tools to evaluate PCa diagnosis and prognosis, of which many are readily available or under evaluation. The aim of this review is to investigate the biomarker performance for AS selection and patient outcome prediction. Blood, urinary and tissue biomarkers were studied and a brief description of use was proposed along with a summary of major findings. Biomarkers represent promising tools which could be part of a more tailored risk AS strategy aiming to offer personalized medicine and to individualize the treatment and monitoring of each patient. The usefulness of biomarkers has mainly been suggested for AS selection, whereas few studies have investigated their role during the monitoring phase. Randomized prospective studies dealing with imaging are needed as well as larger prospective studies with long-term follow-up and strong oncologic endpoints.

Whole-Body Integrated [68Ga]PSMA-11-PET/MR Imaging in Patients with Recurrent Prostate Cancer: Comparison with Whole-Body PET/CT as the Standard of Reference

PURPOSE

The aim of this study was to evaluate the detection rate of [⁶⁸Ga]prostate-specific membrane antigen ([⁶⁸Ga]PSMA-11) positron emission tomography (PET)/magnetic resonance imaging (MRI) and to compare it with [⁶⁸Ga]PSMA-11 PET/X-ray computed tomography (CT) in patients with recurrent prostate cancer (PC) after radical prostatectomy.

PROCEDURES

A total of 93 patients with biochemically recurrent prostate cancer underwent [⁶⁸Ga]PSMA-11 PET/CT and subsequently a whole-body integrated PET/MRI examination. Board certified nuclear medicine physicians and radiologists evaluated PET/CT and PET/MRI datasets regarding identification of tumor lesions ((i) lymph nodes, (ii) bone lesions, (iii) local recurrence, and (iv) parenchymal lesions) based on maximum [⁶⁸Ga]PSMA-11 uptake as well as morphological changes. Quality of PET images for both PET/CT and PET/MRI were rated using a 5-point scoring system by evaluating lesion homogeneity, contrast, contour, and delineation. Wilcoxon signed-rank tests were used to determine statistical differences.

RESULTS

PC relapse was detected in 62/93 patients. PET/MRI detected 148 out of 150 lesions described in PET/CT. In addition, PET/MRI detected 11 lesions not detected in PET/CT (5 lymph nodes, 6 local recurrences). The exact McNemar statistical test (one-sided) showed significant difference between PET/CT and PET/MRI for diagnosis of local recurrence (p value = 0.031). Diagnostic confidence for (iii) was higher in PET/MRI compared with PET/CT (PET/CT = 1.1; PET/MRI = 4.9). Diagnostic confidence for (i) (PET/CT = 4.9; PET/MRI = 4.6), (ii) (PET/CT = 4.9; PET/MRI = 4.6), and (iv) (PET/CT = 4.6; PET/MRI = 4.8) was equivalent between PET/MRI and PET/CT.

CONCLUSIONS

Integrated [⁶⁸Ga]PSMA-11 PET/MRI provides a similarly high diagnostic performance for localization of recurrent PC as PET/CT. For the detection of local recurrences [⁶⁸Ga]PSMA-11 PET/MRI is superior compared with [⁶⁸Ga]PSMA-11 PET/CT.