PI-QUAL version 2: an update of a standardised scoring system for the assessment of image quality of prostate MRI

Multiparametric MRI is the optimal primary investigation when prostate cancer is suspected, and its ability to rule in and rule out clinically significant disease relies on high-quality anatomical and functional images. Avenues for achieving consistent high-quality acquisitions include meticulous patient preparation, scanner setup, optimised pulse sequences, personnel training, and artificial intelligence systems. The impact of these interventions on the final images needs to be quantified. The prostate imaging quality (PI-QUAL) scoring system was the first standardised quantification method that demonstrated the potential for clinical benefit by relating image quality to cancer detection ability by MRI. We present the updated version of PI-QUAL (PI-QUAL v2) which applies to prostate MRI performed with or without intravenous contrast medium using a simplified 3-point scale focused on critical technical and qualitative image parameters. CLINICAL RELEVANCE STATEMENT: High image quality is crucial for prostate MRI, and the updated version of the PI-QUAL score (PI-QUAL v2) aims to address the limitations of version 1. It is now applicable to both multiparametric MRI and MRI without intravenous contrast medium. KEY POINTS: High-quality images are essential for prostate cancer diagnosis and management using MRI. PI-QUAL v2 simplifies image assessment and expands its applicability to prostate MRI without contrast medium. PI-QUAL v2 focuses on critical technical and qualitative image parameters and emphasises T2-WI and DWI.

ESR Essentials: using the right scoring system in prostate MRI-practice recommendations by ESUR

MRI has gained prominence in the diagnostic workup of prostate cancer (PCa) patients, with the Prostate Imaging Reporting and Data System (PI-RADS) being widely used for cancer detection. Beyond PI-RADS, other MRI-based scoring tools have emerged to address broader aspects within the PCa domain. However, the multitude of available MRI-based grading systems has led to inconsistencies in their application within clinical workflows. The Prostate Cancer Radiological Estimation of Change in Sequential Evaluation (PRECISE) assesses the likelihood of clinically significant radiological changes of PCa during active surveillance, and the Prostate Imaging for Local Recurrence Reporting (PI-RR) scoring system evaluates the risk of local recurrence after whole-gland therapies with curative intent. Underlying any system is the requirement to assess image quality using the Prostate Imaging Quality Scoring System (PI-QUAL). This article offers practicing radiologists a comprehensive overview of currently available scoring systems with clinical evidence supporting their use for managing PCa patients to enhance consistency in interpretation and facilitate effective communication with referring clinicians. KEY POINTS: Assessing image quality is essential for all prostate MRI interpretations and the PI-QUAL score represents  the standardized tool for this purpose. Current urological clinical guidelines for prostate cancer diagnosis and localization recommend adhering to the PI-RADS recommendations. The PRECISE and PI-RR scoring systems can be used for assessing radiological changes of prostate cancer during active surveillance and the likelihood of local recurrence after radical treatments respectively.

Preoperative risk calculator for the probability of completing nephron sparing for kidney cancer

PURPOSE

In absence of predictive models, preoperative estimation of the probability of completing partial (PN) relative to radical nephrectomy (RN) is invariably inaccurate and subjective. We aimed to develop an evidence-based model to assess objectively the probability of PN completion based on patients' characteristics, tumor's complexity, urologist expertise and surgical approach.

DESIGN, SETTING AND PARTICIPANTS

675 patients treated with PN or RN for cT1-2 cN0 cM0 renal mass by seven surgeons at one single experienced centre from 2000 to 2019.

OUTCOMES MEASUREMENTS AND STATISTICAL ANALYSES

The outcome of the study was PN completion. We used a multivariable logistic regression (MVA) model to investigate predictors of PN completion. We used SPARE score to assess tumor complexity. We used a bootstrap validation to compute the model's predictive accuracy. We investigated the relationship between the outcomes and specific predictors of interest such as tumor's complexity, approach and experience.

RESULTS

Of 675 patients, 360 (53%) were treated with PN vs. 315 (47%) with RN. Smaller tumors [Odds ratio (OR): 0.52, 95%CI 0.44-0.61; P < 0.001], lower SPARE score (OR: 0.67, 95%CI 0.47-0.94; P = 0.02), more experienced surgeons (OR: 1.01, 95%CI 1.00-1.02; P < 0.01), robotic (OR: 10; P < 0.001) and open (OR: 36; P < 0.001) compared to laparoscopic approach resulted associated with higher probability of PN completion. Predictive accuracy of the model was 0.94 (95% CI 0.93-0.95).

CONCLUSIONS

The probability of PN completion can be preoperatively assessed, with optimal accuracy relaying on routinely available clinical information. The proposed model might be useful in preoperative decision-making, patient consensus, or during preoperative counselling.

PATIENT SUMMARY

In patients with a renal mass the probability of completing a partial nephrectomy varies considerably and without a predictive model is invariably inaccurate and subjective. In this study we build-up a risk calculator based on easily available preoperative variables that can predict with optimal accuracy the probability of not removing the entire kidney.

Variability of mpMRI diagnostic performance according to the upfront individual patient risk of having clinically significant prostate cancer

BACKGROUND

To assess the variation of multiparametric magnetic resonance imaging (mpMRI) positive predictive value (PPV) according to each patient's risk of clinically significant prostate cancer (csPCa) based exclusively on clinical factors.

METHODS

We evaluated 999 patients with positive mpMRI (PI-RADS ≥ 3) receiving targeted (TBx) plus systematic prostate biopsy. We built a multivariable logistic regression analysis (MVA) using clinical risk factors to calculate the individual patients' risk of harboring csPCa at TBx. A second MVA tested the association between individual patients' clinical risk and mpMRI PPV accounting for the PI-RADS score. Finally, we plotted the PPV of each PI-RADS score by the individual patient pretest probability of csPCa using a LOWESS approach.

RESULTS

Overall, TBx found csPCa in 21%, 51%, and 80% of patients with PI-RADS 3, 4, and 5 lesions, respectively. At MVA, age, PSA, digital rectal examination (DRE), and prostate volume were significantly associated with the risk of csPCa at biopsy. DRE yielded the highest odds ratio (OR: 2.88; p < 0.001). The individual patient's clinical risk was significantly associated with mpMRI PPV (OR: 2.49; p < 0.001) using MVA. Plotting the mpMRI PPV according to the predicted clinical risks, we observed that for patients with clinical risk close to 0 versus patients with risk higher than 90%, the mpMRI PPV of PI-RADS 3, 4, and 5 ranged from 0% to 75%, from 0% to 96%, and from 45% to 100%, respectively.

CONCLUSION

mpMRI PPV varies according to the individual pretest patient's risk based on clinical factors. These findings should be considered in the decision-making process for patients with suspect MRI findings referred for a prostate biopsy. Moreover, our data support the need for further studies to create an individualized risk prediction tool.

Vesical Imaging-Reporting and Data System use predicting the outcome of neoadjuvant pembrolizumab in muscle-invasive bladder cancer

OBJECTIVE

To evaluate the predictive capability of the pre- and post-pembrolizumab Vesical Imaging-Reporting and Data System (VI-RADS) to identify ypT0N0 or ypT≤1N0 response in muscle-invasive bladder cancer (MIBC) within the PURE-01 trial (ClinicalTrials.gov identifier: NCT02736266).

PATIENTS AND METHODS

Patients were staged with bladder multiparametric magnetic resonance imaging (mpMRI) before and after treatment (three cycles of pembrolizumab) prior to radical cystectomy (RC). Logistic regression models were used to analyse the pre- and post- pembrolizumab VI-RADS against ypT≤1N0 and ypT0N0 response. The VI-RADS scores were dichotomised between 0 and 3 (0 = no evidence of disease) and 4-5. Event-free survival (EFS) and overall survival (OS) analyses were performed. Comprehensive genomic profiling and transcriptome-wide expression profiling data were matched with the VI-RADS scores.

RESULTS

In total, 110 patients underwent centrally reviewed scans (N = 220 mpMRI), treated between February 2017 and July 2020. Both pre- and post-pembrolizumab VI-RADS 0-3 scores were the only significant covariates that predicted the ypT≤1N0 endpoint in multivariable analyses, and the strongest effect was seen with post-pembrolizumab VI-RADS 0-3 predicting the ypT≤1N0 response (P < 0.001). The area under the curve for this model was 0.90. Post-pembrolizumab VI-RADS 0-3 also predicted a longer EFS (P < 0.001) and OS (P = 0.044). The scores of several gene signatures from baseline tumours differed between the pre-pembrolizumab VI-RADS 0-3 and 4-5 categories.

CONCLUSION

Post-pembrolizumab VI-RADS scores are strongly associated with pathological downstaging and survival. VI-RADS scores were also characterised by distinct biomarker features. These results indicate that the VI-RADS is emerging as an important tool for designing next-generation trials for MIBC.

Diagnostic accuracy of fully hybrid [68Ga]Ga-PSMA-11 PET/MRI and [68Ga]Ga-RM2 PET/MRI in patients with biochemically recurrent prostate cancer: a prospective single-center phase II clinical trial

PURPOSE

To compare the diagnostic accuracy and detection rates of PET/MRI with [68Ga]Ga-PSMA-11 and [68Ga]Ga-M2 in patients with biochemical recurrence of prostate cancer (PCa).

METHODS

Sixty patients were enrolled in this prospective single-center phase II clinical trial from June 2020 to October 2022. Forty-four/60 completed all study examinations and were available at follow-up (median: 22.8 months, range: 6-31.5 months). Two nuclear medicine physicians analyzed PET images and two radiologists interpreted MRI; images were then re-examined to produce an integrated PET/MRI report for both [68Ga]Ga-PSMA-11 and [68Ga]Ga-RM2 examinations. A composite reference standard including histological specimens, response to treatment, and conventional imaging gathered during follow-up was used to validate imaging findings. Detection rates, accuracy, sensitivity, specificity, positive, and negative predictive value were assessed. McNemar's test was used to compare sensitivity and specificity on a per-patient base and detection rate on a per-region base. Prostate bed, locoregional lymph nodes, non-skeletal distant metastases, and bone metastases were considered. p-value significance was defined below the 0.05 level after correction for multiple testing.

RESULTS

Patients' median age was 69.8 years (interquartile range (IQR): 61.8-75.1) and median PSA level at time of imaging was 0.53 ng/mL (IQR: 0.33-2.04). During follow-up, evidence of recurrence was observed in 31/44 patients. Combining MRI with [68Ga]Ga-PSMA-11 PET and [68Ga]Ga-RM2 PET resulted in sensitivity = 100% and 93.5% and specificity of 69.2% and 69.2%, respectively. When considering the individual imaging modalities, [68Ga]Ga-RM2 PET showed lower sensitivity compared to [68Ga]Ga-PSMA-11 PET and MRI (61.3% vs 83.9% and 87.1%, p = 0.046 and 0.043, respectively), while specificity was comparable among the imaging modalities (100% vs 84.6% and 69.2%, p = 0.479 and 0.134, respectively).

CONCLUSION

This study brings further evidence on the utility of fully hybrid PET/MRI for disease characterization in patients with biochemically recurrent PCa. Imaging with [68Ga]Ga-PSMA-11 PET showed high sensitivity, while the utility of [68Ga]Ga-RM2 PET in absence of a simultaneous whole-body/multiparametric MRI remains to be determined.

First-in-human in-vivo depiction of paraganglioma metabolism by hyperpolarised 13C-magnetic resonance

Phaeochromocytomas (PCC) and paragangliomas (PGL), cumulatively referred to as PPGLs, are neuroendocrine tumours arising from neural crest-derived cells in the sympathetic and parasympathetic nervous systems. Predicting future tumour behaviour and the likelihood of metastatic disease remains problematic as genotype-phenotype correlations are limited, the disease has variable penetrance and, to date, no reliable molecular, cellular or histological markers have emerged. Tumour metabolism quantification can be considered as a method to delineating tumour aggressiveness by utilising hyperpolarised 13 C-MR (HP-MR). The technique may provide an opportunity to non-invasively characterise disease behaviour. Here, we present the first instance of the analysis of PPGL metabolism via HP-MR in a single case.

Impact of prostate MRI central review over the diagnostic performance of MRI-targeted biopsy: should we routinely ask for an expert second opinion?

PURPOSE

There is substantial variability in multiparametric MRI (mpMRI) protocols and inter-readers' agreement. We tested the effect of a central mpMRI review on the detection of clinically significant PCa (csPCa) in a tertiary referral center.

METHODS

We retrospectively analyzed a cohort of 364 consecutive men with a positive externally performed mpMRI (PI-RADS ≥ 3) who underwent a targeted biopsy (TBx) plus a systematic biopsy at a single tertiary referral center (2018-2020). Of those mpMRIs, 32% (n = 116) were centrally reviewed. We compared the detection of csPCa between the non-central-reviewed vs reviewed group. Multivariable logistic regression models (MVA) tested the relationship between mpMRI central review and the detection of csPCa at TBx.

RESULTS

The detection of csPCa at TBx in non-central-reviewed vs central-reviewed group was 41 vs 63%, respectively (p = 0.001). The distribution of PI-RADS 2, 3, 4, and 5 at initial assessment vs after mpMRI central review was 0, 37, 47, and 16% vs 39, 9, 35, and 16%, respectively (p < 0.004). Of 43 patients with initial PI-RADS 3 score, respectively 67, 21, and 12, and 0% had a revised PI-RADS score of ≤ 2, 3, 4, and 5. At MVA, mpMRI central review (OR: 1.65, CI 0.85-0.98) was significantly associated with higher csPCa detection at TBx.

CONCLUSIONS

We demonstrated that a central review of external mpMRIs may decrease the overcall of equivocal lesions, namely PI-RADS 3, and should be considered to maximize the clinical benefit of TBx in terms of increasing the detection of csPCa and eventually decreasing the rate of unnecessary biopsies.

Added Value of Prostate-specific Antigen Density in Selecting Prostate Biopsy Candidates Among Men with Elevated Prostate-specific Antigen and PI-RADS ≥3 Lesions on Multiparametric Magnetic Resonance Imaging of the Prostate: A Systematic Assessment by PI-RADS Score

BACKGROUND

A significant proportion of patients with positive multiparametric magnetic resonance imaging (mpMRI; Prostate Imaging-Reporting and Data System [PI-RADS] scores of 3-5) have negative biopsy results.

OBJECTIVE

To systematically assess all prostate-specific antigen density (PSAD) values and identify an appropriate cutoff for identification of patients with positive mpMRI who could potentially avoid biopsy on the basis of their PI-RADS score.

DESIGN, SETTING, AND PARTICIPANTS

The study included a cohort of 1341 patients with positive mpMRI who underwent combined targeted and systematic biopsies.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

Multivariable logistic regression analysis (MVA) was used to assess the association between PSAD and the risk of clinically significant prostate cancer (csPCa, grade group ≥2) after adjusting for confounders. We used locally weighted scatterplot smoothing to explore csPCa risk according to PSAD and PI-RADS scores. PSAD utility was observed only for patients with PI-RADS 3 lesions, so we plotted the effect of each PSAD value as a cutoff for this subgroup in terms of biopsies saved, csPCa cases missed, and clinically insignificant PCa (ciPCa, grade group 1) cases not detected.

RESULTS AND LIMITATIONS

Overall, 667 (50%) csPCa cases were identified. On MVA, PSAD independently predicted csPCa (odds ratio 1.57; p < 0.001). For PI-RADS ≥4 lesions, the csPCa risk was ≥40% regardless of PSAD. Conversely, among patients with PI-RADS 3 lesions, csPCa risk ranged from 0% to 60% according to PSAD values, and a PSAD cutoff of 0.10 ng/ml/cm3 corresponded to a threshold probability of 10% for csPCa. Using this PSAD cutoff for patients with PI-RADS 3 lesions would have saved 32% of biopsies, missed 7% of csPCa cases, and avoided detection of 34% of ciPCa cases. Limitations include selection bias and the high experience of the radiologists and urologists involved.

CONCLUSIONS

Patients with PI-RADS ≥4 lesions should undergo prostate biopsy regardless of their PSAD, while PSAD should be used to stratify patients with PI-RADS 3 lesions. Using a threshold probability of 10% for csPCa, our data suggest that the appropriate strategy is to avoid biopsy in patients with PI-RADS 3 lesions and PSAD <0.10 ng/ml/cm3. Our results also provide information to help in tailoring an appropriate strategy for every patient with positive mpMRI findings.

PATIENT SUMMARY

We investigated whether a cutoff value for PSAD (prostate-specific antigen density) could identify patients with suspicious prostate lesions on MRI (magnetic resonance imaging) who could avoid biopsy according to the PI-RADS score for their scan. We found that patients with PI-RADS ≥4 should undergo prostate biopsy regardless of their PSAD. A PSAD cutoff of 0.10 should be used to stratify patients with PI-RADS 3.

Dissemination of endometrial cancer MRI staging guidelines among young radiologists: an ESUR Junior Network survey

OBJECTIVES

Imaging guidelines could play an important role in the training of radiologists, but the extent of their adoption in residency programs is unclear. With this survey, the European Society of Urogenital Radiology (ESUR) Junior Network aimed to assess the dissemination of the ESUR guidelines on endometrial cancer MRI staging (EC-ESUR guidelines) among young radiologists.

METHODS

An online questionnaire targeted to last year radiology residents and radiologists in the first year of their career was designed. It included 24 questions, structured in 4 sections (i.e., background, general, acquisition protocol, interpretation, and reporting). The survey was active between April and May 2022, accepting answers worldwide. Answers were solicited with a social media campaign and with the support of national scientific societies. Subgroup analysis was performed based on variables such as subspecialty of interest and number of EC-ESUR guidelines consultations using the Wilcoxon rank sum test.

RESULTS

In total, 118 participants completed the questionnaire, of which 94 (80%) were from Europe and 46 (39%) with a special interest in urogenital radiology. Overall, 68 (58%) stated that the guidelines were not part of their residency teaching programs while 32 (27%) had never even consulted the guidelines. Interest in urogenital radiology as a subspecialty and EC-ESUR guidelines consultations were associated with greater confidence in supervising scan acquisition, interpreting, and reporting EC MRI staging exams.

CONCLUSION

Four years after publication, the adoption of EC-ESUR guidelines in residency programs is heterogeneously low. Despite a possible selection bias, our findings indicate that active promotion of EC-ESUR guidelines is required.

KEY POINTS

• The adoption of ESUR guidelines on endometrial cancer in radiology residency programs is heterogeneous. • Almost one third of respondents stated they had never even consulted the guidelines. • Confidence toward guidelines was higher in those who were exposed to more endometrial cancer MRI staging scans. • Reading the guidelines was associated with a greater confidence in protocol acquisition, interpretation, and reporting. • Active efforts to promote their dissemination are required.

Extraprostatic incidental findings on prostate mpMRI: A pictorial review from the ESUR junior network

The role of multiparametric MRI (mpMRI) in prostate cancer setting is increasingly consolidated and, as a result, its usage in clinical practice is in exponential growth. However, beyond the prostate gland, several key structures are included in the field of view of mpMRI scans. Consequently, various extra-prostatic incidental findings (IFs) belonging to different anatomical systems can be accidentally recognized. Therefore, it is mandatory for a radiologist to be familiar with the wide range of pathologies potentially encountered, to guide management and avoid patient anxiety and costs due to additional work-up prompted by clinically insignificant extra-prostatic findings. With this pictorial review, we aim to illustrate a wide range of IFs that can be detected when performing mpMRI of the prostate, focusing on their imaging characteristics, differential diagnosis, and clinical relevance. Additionally, we propose the CheckDEEP, the Checklist for DEtection of ExtraProstatic findings, to be used for a thorough evaluation of target areas within each anatomical system.

[68Ga]Ga-PSMA and [68Ga]Ga-RM2 PET/MRI vs. Histopathological Images in Prostate Cancer: A New Workflow for Spatial Co-Registration

This study proposed a new workflow for co-registering prostate PET images from a dual-tracer PET/MRI study with histopathological images of resected prostate specimens. The method aims to establish an accurate correspondence between PET/MRI findings and histology, facilitating a deeper understanding of PET tracer distribution and enabling advanced analyses like radiomics. To achieve this, images derived by three patients who underwent both [68Ga]Ga-PSMA and [68Ga]Ga-RM2 PET/MRI before radical prostatectomy were selected. After surgery, in the resected fresh specimens, fiducial markers visible on both histology and MR images were inserted. An ex vivo MRI of the prostate served as an intermediate step for co-registration between histological specimens and in vivo MRI examinations. The co-registration workflow involved five steps, ensuring alignment between histopathological images and PET/MRI data. The target registration error (TRE) was calculated to assess the precision of the co-registration. Furthermore, the DICE score was computed between the dominant intraprostatic tumor lesions delineated by the pathologist and the nuclear medicine physician. The TRE for the co-registration of histopathology and in vivo images was 1.59 mm, while the DICE score related to the site of increased intraprostatic uptake on [68Ga]Ga-PSMA and [68Ga]Ga-RM2 PET images was 0.54 and 0.75, respectively. This work shows an accurate co-registration method for histopathological and in vivo PET/MRI prostate examinations that allows the quantitative assessment of dual-tracer PET/MRI diagnostic accuracy at a millimetric scale. This approach may unveil radiotracer uptake mechanisms and identify new PET/MRI biomarkers, thus establishing the basis for precision medicine and future analyses, such as radiomics.

Role of [68Ga]Ga-PSMA-11 PET radiomics to predict post-surgical ISUP grade in primary prostate cancer

PURPOSE

The aim of this study is to investigate the role of [68Ga]Ga-PSMA-11 PET radiomics for the prediction of post-surgical International Society of Urological Pathology (PSISUP) grade in primary prostate cancer (PCa).

METHODS

This retrospective study included 47 PCa patients who underwent [68Ga]Ga-PSMA-11 PET at IRCCS San Raffaele Scientific Institute before radical prostatectomy. The whole prostate was manually contoured on PET images and 103 image biomarker standardization initiative (IBSI)-compliant radiomic features (RFs) were extracted. Features were then selected using the minimum redundancy maximum relevance algorithm and a combination of the 4 most relevant RFs was used to train 12 radiomics machine learning models for the prediction of PSISUP grade: ISUP ≥ 4 vs ISUP < 4. Machine learning models were validated by means of fivefold repeated cross-validation, and two control models were generated to assess that our findings were not surrogates of spurious associations. Balanced accuracy (bACC) was collected for all generated models and compared with Kruskal-Wallis and Mann-Whitney tests. Sensitivity, specificity, and positive and negative predictive values were also reported to provide a complete overview of models' performance. The predictions of the best performing model were compared against ISUP grade at biopsy.

RESULTS

ISUP grade at biopsy was upgraded in 9/47 patients after prostatectomy, resulting in a bACC = 85.9%, SN = 71.9%, SP = 100%, PPV = 100%, and NPV = 62.5%, while the best-performing radiomic model yielded a bACC = 87.6%, SN = 88.6%, SP = 86.7%, PPV = 94%, and NPV = 82.5%. All radiomic models trained with at least 2 RFs (GLSZM-Zone Entropy and Shape-Least Axis Length) outperformed the control models. Conversely, no significant differences were found for radiomic models trained with 2 or more RFs (Mann-Whitney p > 0.05).

CONCLUSION

These findings support the role of [68Ga]Ga-PSMA-11 PET radiomics for the accurate and non-invasive prediction of PSISUP grade.

Quantification of Prostate Cancer Metabolism Using 3D Multiecho bSSFP and Hyperpolarized [1-13 C] Pyruvate: Metabolism Differs Between Tumors of the Same Gleason Grade

BACKGROUND

Three-dimensional (3D) multiecho balanced steady-state free precession (ME-bSSFP) has previously been demonstrated in preclinical hyperpolarized (HP) 13 C-MRI in vivo experiments, and it may be suitable for clinical metabolic imaging of prostate cancer (PCa).

PURPOSE

To validate a signal simulation framework for the use of sequence parameter optimization. To demonstrate the feasibility of ME-bSSFP for HP 13 C-MRI in patients. To evaluate the metabolism in PCa measured by ME-bSSFP.

STUDY TYPE

Retrospective single-center cohort study.

PHANTOMS/POPULATION

Phantoms containing aqueous solutions of [1-13 C] lactate (2.3 M) and [13 C] urea (8 M). Eight patients (mean age 67 ± 6 years) with biopsy-confirmed Gleason 3 + 4 (n = 7) and 4 + 3 (n = 1) PCa. FIELD STRENGTH/SEQUENCES: 1 H MRI at 3 T with T2 -weighted turbo spin-echo sequence used for spatial localization and spoiled dual gradient-echo sequence used for B0 -field measurement. ME-bSSFP sequence for 13 C MR spectroscopic imaging with retrospective multipoint IDEAL metabolite separation.

ASSESSMENT

The primary endpoint was the analysis of pyruvate-to-lactate conversion in PCa and healthy prostate regions of interest (ROIs) using model-free area under the curve (AUC) ratios and a one-directional kinetic model (kP ). The secondary objectives were to investigate the correlation between simulated and experimental ME-bSSFP metabolite signals for HP 13 C-MRI parameter optimization.

STATISTICAL TESTS

Pearson correlation coefficients with 95% confidence intervals and paired t-tests. The level of statistical significance was set at P < 0.05.

RESULTS

Strong correlations between simulated and empirical ME-bSSFP signals were found (r > 0.96). Therefore, the simulation framework was used for sequence optimization. Whole prostate metabolic HP 13 C-MRI, observing the conversion of pyruvate into lactate, with a temporal resolution of 6 seconds was demonstrated using ME-bSSFP. Both assessed metrics resulted in significant differences between PCa (mean ± SD) (AUC = 0.33 ± 012, kP  = 0.038 ± 0.014) and healthy (AUC = 0.15 ± 0.10, kP  = 0.011 ± 0.007) ROIs.

DATA CONCLUSION

Metabolic HP 13 C-MRI in the prostate using ME-bSSFP allows for differentiation between aggressive PCa and healthy tissue.

EVIDENCE LEVEL

2 TECHNICAL EFFICACY: Stage 1.

Impact of prostate imaging quality (PI-QUAL) score on the detection of clinically significant prostate cancer at biopsy

PURPOSE

To investigate the impact of Prostate Imaging Quality (PI-QUAL) scores on the diagnostic performance of multiparametric MRI (mpMRI) in a targeted biopsy cohort.

PATIENTS AND METHODS

300 patients who underwent both mpMRI and biopsy were included. PI-QUAL scores were retrospectively assigned by two radiologists in consensus and were correlated to pre-biopsy PI-RADS scores and biopsy outcomes. Clinically significant prostate cancer (csPCa) was defined as ISUP grade ≥ 2.

RESULTS

Image quality was optimal (PI-QUAL ≥ 4) in 249/300 (83%) and suboptimal (PI-QUAL < 4) in 51/300 (17%). The proportion of PI-RADS 3 scores referred for biopsy was higher in scans of suboptimal vs optimal quality (51% vs 33%). For PI-QUAL < 4 scans, the positive predictive value (PPV) was lower compared to PI-QUAL ≥ 4 (35% [95%CI: 22, 48] vs 48% [95%CI: 41, 55]; difference -13% [95%CI: -27, 2]; p 0.090), as was the detection rate of csPCa in both PI-RADS 3 and PI-RADS 4-5 (15% vs 23% and 56 vs 63%, respectively). The overall MRI quality increased over time.

CONCLUSIONS

Scan quality may affect the diagnostic performance of prostate mpMRI in patients undergoing MRI-guided biopsy. Scans of suboptimal quality (PI-QUAL < 4) were associated with lower PPV for csPCa.

Beyond diagnosis: is there a role for radiomics in prostate cancer management?

The role of imaging in pretreatment staging and management of prostate cancer (PCa) is constantly evolving. In the last decade, there has been an ever-growing interest in radiomics as an image analysis approach able to extract objective quantitative features that are missed by human eye. However, most of PCa radiomics studies have been focused on cancer detection and characterisation. With this narrative review we aimed to provide a synopsis of the recently proposed potential applications of radiomics for PCa with a management-based approach, focusing on primary treatments with curative intent and active surveillance as well as highlighting on recurrent disease after primary treatment. Current evidence is encouraging, with radiomics and artificial intelligence appearing as feasible tools to aid physicians in planning PCa management. However, the lack of external independent datasets for validation and prospectively designed studies casts a shadow on the reliability and generalisability of radiomics models, delaying their translation into clinical practice.Key points• Artificial intelligence solutions have been proposed to streamline prostate cancer radiotherapy planning.• Radiomics models could improve risk assessment for radical prostatectomy patient selection.• Delta-radiomics appears promising for the management of patients under active surveillance.• Radiomics might outperform current nomograms for prostate cancer recurrence risk assessment.• Reproducibility of results, methodological and ethical issues must still be faced before clinical implementation.

Utility of pre- and post-pembrolizumab (Pembro) Vesical Imaging–Reporting and Data System (VIRADS) to predict the pathological response in muscle-invasive urothelial bladder cancer (MIBC): An analysis of the PURE-01 cohort

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Background: The possibility to predict the pathologic complete response (pT0) or downstaging (pT≤1) after neoadjuvant therapy may have profound impact on the management of MIBC and orient next-generation bladder-sparing trials. The VIRADS is a standardized reporting system that uses mpMRI parameters to predict the probability of MIBC. No studies have analyzed the ability of VIRADS to predict the pT0 or pT≤1 response post-immunotherapy (IO). Methods: In PURE-01 patients (pts) were staged with bladder multiparametric magnetic resonance imaging (mpMRI: T2-weighted imaging, diffusion-weighted imaging, dynamic contrast enhancement) before and after treatment (3 cycles of pembro) prior to radical cystectomy (RC). All mpMRI scans were centrally reviewed. Logistic regression models analyzed pre- and post-pembro VIRADS against pT≤1 (primary endpoint) and pT0 (secondary endpoint). VIRADS scores were dichotomized between 0-3 and 4-5. Covariates included cT-stage, age, gender, PD-L1 combined positive score (CPS) and tumor mutational burden (TMB). Results: In total, 58 pts were had centrally-reviewed MRI scans (N=116 mpMRI), treated between 02/17 and 08/18. Demographic characteristics and outcomes were generally similar between the all-treated and VIRADS-evaluable populations of PURE-01. Median age was 65 years, 52 (89%) had pure/predominant urothelial carcinoma (UC) histology, 25 (43.1%) had cT3-4N0 MIBC. Pre-pembro: 8 pts (13.8%) had no measurable disease (VIRADS=0), 20 (34.5%) a VIRADS 1-3 score, and 30 (51.7%) had a VIRADS 4-5 score. Six pts (10.3%) had a downstage from VIRADS 4-5 to VIRADS 0-3 post-pembro. Both pre-pembro and post-pembro VIRADS 0-3 scores were significantly associated with pT≤1 endpoint on multivariable analyses (MVA): the strongest effect was seen with post-pembro VIRADS 0-3 against pT≤1 response (OR: 30.2, 95%CI: 6.2-223.2, p<0.0001). The AUC of this model was 0.92. Regarding pre-pembro VIRADS 0-3: OR: 4.35, 95%CI: 1.1-19.7, p=0.04; AUC: 0.83. CPS was another significant variable for pT≤1 endpoint only in MVA using pre-pembro VIRADS 0-3 (OR: 1.02, 95%CI: 1-1.05, p=0.02). Post-pembro VIRADS 0-3 was also associated with pT0 on MVA (OR: 4.59, 95%CI: 1.2-19.6, p=0.02; AUC: 0.78), whereas pre-pembro VIRADS was not (p=0.13). Mean apparent diffusion coefficients (ADC) were similar between pre- and post-pembro lesions (0.86 vs 0.87). Conclusions: To our knowledge, this is the first evidence establishing the predictivity of the VIRADS score towards the pathological downstaging, both in the pre and post IO settings. Post-pembro VIRADS, along with the combination of pre-pembro VIRADS and CPS, emerged as the strongest features based on which selecting pts for bladder-sparing strategies. Clinical trial information: NCT02736266 .

External validation of a convolutional neural network for the automatic segmentation of intraprostatic tumor lesions on 68Ga-PSMA PET images

Introduction

State of the art artificial intelligence (AI) models have the potential to become a "one-stop shop" to improve diagnosis and prognosis in several oncological settings. The external validation of AI models on independent cohorts is essential to evaluate their generalization ability, hence their potential utility in clinical practice. In this study we tested on a large, separate cohort a recently proposed state-of-the-art convolutional neural network for the automatic segmentation of intraprostatic cancer lesions on PSMA PET images.

Methods

Eighty-five biopsy proven prostate cancer patients who underwent ⁶⁸Ga PSMA PET for staging purposes were enrolled in this study. Images were acquired with either fully hybrid PET/MRI (N = 46) or PET/CT (N = 39); all participants showed at least one intraprostatic pathological finding on PET images that was independently segmented by two Nuclear Medicine physicians. The trained model was available at https://gitlab.com/dejankostyszyn/prostate-gtv-segmentation and data processing has been done in agreement with the reference work.

Results

When compared to the manual contouring, the AI model yielded a median dice score = 0.74, therefore showing a moderately good performance. Results were robust to the modality used to acquire images (PET/CT or PET/MRI) and to the ground truth labels (no significant difference between the model's performance when compared to reader 1 or reader 2 manual contouring).

Discussion

In conclusion, this AI model could be used to automatically segment intraprostatic cancer lesions for research purposes, as instance to define the volume of interest for radiomics or deep learning analysis. However, more robust performance is needed for the generation of AI-based decision support technologies to be proposed in clinical practice.

Assessing the need for systematic biopsies in addition to targeted biopsies according to the characteristics of the index lesion at mpMRI. Results from a large, multi-institutional database

PURPOSE

We hypothesized that systematic biopsies (SBx) value for clinically significant PCa (csPCa) detection, in addition to mpMRI targeted biopsies (TBx), may vary significantly according to mpMRI index lesion (IL) characteristics.

METHODS

We identified 1350 men with an mpMRI suspicious lesion (PI-RADS ≥ 3), defined as IL, who underwent TBx and SBx at three referral centres. The outcome was SBx added value in csPCa (grade group ≥ 2 PCa detected at SBx and missed by TBx) detection. To this aim, we performed multivariable logistic regression analyses (MVA). Furthermore, we explored the interaction between IL volume and SBx csPCa added value, across different PI-RADS categories, using lowess function.

RESULTS

Overall, 569 (42%) men had csPCa at TBx and 78 (6%) csPCa were identified at SBx only. At MVA PSA (OR 0.90; p < 0.05) and IL volume (OR 0.58; p < 0.05) were associated with SBx csPCa added value. At interaction analyses, a nonlinear correlation between PI-RADS and SBx csPCa added value was identified with a decrease from roughly 10 to 4% followed by a substantial plateau at 1.2 ml and 0.6 ml for PI-RADS 3 and 4, respectively. For PI-RADS 5 lesions SBx csPCa added was constantly lower than 4%.

CONCLUSIONS

Increasing IL volume in PI-RADS 3 and 4 lesions is associated with reduction in SBx csPCa added value. For diagnostic purposes, SBx could be omitted in men with IL larger than 1.2 ml and 0.6 ml for PI-RADS 3 and 4, respectively. Conversely, for PI-RADS 5, SBx csPCa added value was minimal regardless of IL volume.

Does previous prostate surgery affect multiparametric magnetic resonance imaging accuracy in detecting clinically significant prostate cancer? Results from a single institution series

BACKGROUND

Multiparametric MRI (mpMRI) has demonstrated high diagnostic accuracy for clinically significant PCa (csPCa). However, the accuracy of this test in men that received a previous prostatic surgery is still controversial. We aimed at assessing the effect of previous prostatic surgery on the detection of csPCa in a tertiary referral center.

METHOD

We relied on a cohort of 311 men with a positive mpMRI (prostate imaging - reporting and data system [PI-RADS] ≥ 3) who underwent a targeted (TBx) plus concomitant systematic random biopsy (SBx) at a single tertiary referral center between 2017 and 2020. The study outcome was to compare the detection of csPCa (Gleason score ≥ 3 + 4) between the two groups (no previous prostate surgery [Group 1] vs. previous prostate surgery [Group 2]). Multivariable logistic regression analysis (MVA) was used to assess the relationship between previous prostate surgery and the detection of csPCa at TBx, after taking into account potential clinical confounders.

RESULTS

Overall, 24 (8%) patients received a previous prostate surgery before undergoing mpMRI. Median prostate-specific antigen density was 0.15 versus 0.08 ng/ml/cc, in Group 1 versus 2, respectively. The most frequent finding at mpMRI was in Group 1 versus 2, PI-RADS 4 (55%) versus PI-RADS 3 and 4 (42% each). The majority of patients were biopsy naïve in both Groups 1 (66%) and 2 (71%). The overall detection of csPCa in Group 1 versus 2 was 83% versus 75%, respectively. Differently, the detection of csPCa at TBx in Groups 1 versus 2 was 76% versus 71%, respectively. At MVA, previous prostate surgery (odds ratio: 0.65; p = 0.02) was significantly associated with lower csPCa detection at TBx, after accounting for potential confounders.

CONCLUSION

The presence of previous prostate surgery significantly decreases the accuracy of mpMRI in detecting csPCa. These results should be taken into account when assessing patients with a history of prostatic surgery and a suspicious lesion at mpMRI, to better select those who might avoid an unnecessary biopsy.

Pancreatic metastases after surgery for renal cell carcinoma: survival and pathways of progression

PURPOSE

Metastatic ccRCC has peculiar tropism in the pancreas. We describe the characteristics and pathways of progression of patients with PM in a large multi-institutional consortium and compare them to patients with metastases from ccRCC at other sites.

METHODS

Detailed clinical and histopathological data were collected. To account for differences in baseline characteristics between the two groups, IPTW was used to compare the two groups in terms of PFS and OS.

RESULTS

Of the 182 patients, 33 (18%) had pancreatic, 94 (52%) pulmonary, 30 (16%) bone, 13 (7%) hepatic, and 12 (7%) brain metastases. Patients with PM had less aggressive ccRCC at baseline compared to those with progression at other sites in terms of tumour stage and grade. Median time from ccRCC surgery to PM was 8 (95%CI 5-10) vs. 1 year (95%CI 1-2) for progression to other sites (p < 0.001). Median IPTW-weighted time to second progression was 4.3 years (95%CI 2.4-not reached) for patients with PM vs 1.1 year (95%CI 0.8-2.3) for those with progression in other sites (p < 0.001). The most frequent second progression sites were pancreas (24%) and liver (15%) in patients with PM, while progression to the pancreas was rare (4%) in those with a different first progression site. Surgery alone (55%) or in combination with medical therapy (30%) was more frequent in the PM group than in other sites (p < 0.001). Median IPTW-OS time was longer for patients with PM [8.8 years (95%CI 6.5-not reached)] compared to those with first progression in other sites [2.8 years (95%CI 1.9-4.3), p < 0.001].

CONCLUSION

Pancreatic tropism is typical of ccRCC tumours with more indolent behaviour than those progressing to other sites. A long follow-up period is necessary to distinguish PM from ccRCC.

Prostate-specific membrane antigen Radioguided Surgery to Detect Nodal Metastases in Primary Prostate Cancer Patients Undergoing Robot-assisted Radical Prostatectomy and Extended Pelvic Lymph Node Dissection: Results of a Planned Interim Analysis of a Prospective Phase 2 Study

BACKGROUND

Extended pelvic nodal dissection (ePLND) represents the gold standard for nodal staging in prostate cancer (PCa). Prostate-specific membrane antigen (PSMA) radioguided surgery (RGS) could identify lymph node invasion (LNI) during robot-assisted radical prostatectomy (RARP).

OBJECTIVE

To report the planned interim analyses of a phase 2 prospective study (NCT04832958) aimed at describing PSMA-RGS during RARP.

DESIGN, SETTING, AND PARTICIPANTS

A phase 2 trial aimed at enrolling 100 patients with intermediate- or high-risk cN0cM0 PCa at conventional imaging with a risk of LNI of >5% was conducted. Overall, 18 patients were enrolled between June 2021 and March 2022. Among them, 12 patients underwent PSMA-RGS and represented the study cohort.

SURGICAL PROCEDURE

All patients received ⁶⁸Ga-PSMA positron emission tomography (PET)/magnetic resonance imaging; ^99mTc-PSMA-I&S was synthesised and administered intravenously the day before surgery, followed by single-photon emission computed tomography/computed tomography. A Drop-In gamma probe was used for in vivo measurements. All positive lesions (count rate ≥2 compared with background) were excised and ePLND was performed.

MEASUREMENTS

Side effects, perioperative outcomes, and performance characteristics of robot-assisted PSMA-RGS for LNI were measured.

RESULTS AND LIMITATIONS

Overall, four (33%), six (50%), and two (17%) patients had intermediate-risk, high-risk, and locally advanced PCa. Overall, two (17%) patients had pathologic nodal uptake at PSMA PET. The median operative time, blood loss, and length of stay were 230 min, 100 ml, and 5 d, respectively. No adverse events and intraoperative complications were recorded. One patient experienced a 30-d complication (Clavien-Dindo 2; 8.3%). Overall, three (25%) patients had LNI at ePLND. At per-region analyses on 96 nodal areas, sensitivity, specificity, positive predictive value, and negative predictive value of PSMA-RGS were 63%, 99%, 83%, and 96%, respectively. On a per-patient level, sensitivity, specificity, positive predictive value, and negative predictive values of PSMA-RGS were 67%, 100%, 100%, and 90%, respectively.

CONCLUSIONS

Robot-assisted PSMA-RGS in primary staging is a safe and feasible procedure characterised by acceptable specificity but suboptimal sensitivity, missing micrometastatic nodal disease.

PATIENT SUMMARY

Prostate-specific membrane antigen radioguided robot-assisted surgery is a safe and feasible procedure for the intraoperative identification of nodal metastases in cN0cM0 prostate cancer patients undergoing robot-assisted radical prostatectomy with extended pelvic lymph node dissection. However, this approach might still miss micrometastatic nodal dissemination.

The ReIMAGINE prostate cancer risk study protocol: A prospective cohort study in men with a suspicion of prostate cancer who are referred onto an MRI-based diagnostic pathway with donation of tissue, blood and urine for biomarker analyses

INTRODUCTION

The ReIMAGINE Consortium was conceived to develop risk-stratification models that might incorporate the full range of novel prostate cancer (PCa) diagnostics (both commercial and academic).

METHODS

ReIMAGINE Risk is an ethics approved (19/LO/1128) multicentre, prospective, observational cohort study which will recruit 1000 treatment-naive men undergoing a multi-parametric MRI (mpMRI) due to an elevated PSA (≤20ng/ml) or abnormal prostate examination who subsequently had a suspicious mpMRI (score≥3, stage ≤T3bN0M0). Primary outcomes include the detection of ≥Gleason 7 PCa at baseline and time to clinical progression, metastasis and death. Baseline blood, urine, and biopsy cores for fresh prostate tissue samples (2 targeted and 1 non-targeted) will be biobanked for future analysis. High-resolution scanning of pathology whole-slide imaging and MRI-DICOM images will be collected. Consortium partners will be granted access to data and biobanks to develop and validate biomarkers using correlation to mpMRI, biopsy-based disease status and long-term clinical outcomes.

RESULTS

Recruitment began in September 2019(n = 533). A first site opened in September 2019 (n = 296), a second in November 2019 (n = 210) and a third in December 2020 (n = 27). Acceptance to the study has been 65% and a mean of 36.5ml(SD+/-10.0), 12.9ml(SD+/-3.7) and 2.8ml(SD+/-0.7) urine, plasma and serum donated for research, respectively. There are currently 4 academic and 15 commercial partners spanning imaging (~9 radiomics, artificial intelligence/machine learning), fluidic (~3 blood-based and ~2urine-based) and tissue-based (~1) biomarkers.

CONCLUSION

The consortium will develop, or adjust, risk models for PCa, and provide a platform for evaluating the role of novel diagnostics in the era of pre-biopsy MRI and targeted biopsy.

68Ga-PSMA and 68Ga-DOTA-RM2 PET/MRI in Recurrent Prostate Cancer: Diagnostic Performance and Association with Clinical and Histopathological Data

Simple Summary

Prostate cancer (PCa) relapse occurs in up to 50% of patients after radical treatment. Once PCa recurrence is detected, a precise identification of the number and sites of recurrence is necessary to tailor the treatment on the patient’s needs. Positron emission tomography (PET) plays a pivotal role in this clinical setting and new radiotracers have been developed to improve its performance. While ⁶⁸Ga-PSMA is a well-established radiotracer for PCa recurrence detection, ⁶⁸Ga-DOTA-RM2 is a recently proposed tracer that targets the gastrin-releasing peptide receptors that are overexpressed in prostate cancer. In this work, the performance of ⁶⁸Ga-PSMA and ⁶⁸Ga-DOTA-RM2 PET/MRI in identifying recurrent disease were compared on the same cohort, using the same study protocol, as this is the only way to assess whether one outperforms the other and therefore should be preferred in clinical practice. Furthermore, the association between PET findings and clinical and histopathological characteristics was investigated to find potential biomarkers.

Abstract

The aim of the present study is to investigate and compare the performances of ⁶⁸Ga-PSMA and ⁶⁸Ga-DOTA-RM2 PET/MRI in identifying recurrent prostate cancer (PCa) after primary treatment and to explore the association of dual-tracer PET findings with clinical and histopathological characteristics. Thirty-five patients with biochemical relapse (BCR) of PCa underwent ⁶⁸Ga PSMA PET/MRI for restaging purpose, with 31/35 also undergoing ⁶⁸Ga-DOTA-RM2 PET/MRI scan within 16 days (mean: 3 days, range: 2–16 days). Qualitative and quantitative image analysis has been performed by comparing ⁶⁸Ga-PSMA and ⁶⁸Ga-DOTA-RM2 PET/MRI findings both on a patient and lesion basis. Clinical and instrumental follow-up was used to validate PET findings. Fisher’s exact test and Mann-Whitney U test were used to investigate the association between dual-tracer PET findings, clinical and histopathological data. p-value significance was defined below the 0.05 level. Patients’ mean age was 70 years (range: 49–84) and mean PSA at time of PET/MR scans was 1.88 ng/mL (range: 0.21–14.4). A higher detection rate was observed for ⁶⁸Ga-PSMA PET/MRI, with more lesions being detected compared to ⁶⁸Ga-DOTA-RM2 PET/MRI (26/35 patients, 95 lesions vs. 15/31 patients, 41 lesions; p = 0.016 and 0.002). ⁶⁸Ga-PSMA and ⁶⁸Ga-DOTA-RM2 PET/MRI findings were discordant in 11/31 patients; among these, 10 were ⁶⁸Ga-PSMA positive (9/10 confirmed as true positive and 1/10 as false positive by follow-up examination). Patients with higher levels of PSA and shorter PSA doubling time (DT) presented more lesions on ⁶⁸Ga-PSMA PET/MRI (p = 0.006 and 0.044), while no association was found between PET findings and Gleason score. ⁶⁸Ga-PSMA has a higher detection rate than ⁶⁸Ga-DOTA-RM2 in detecting PCa recurrence. The number of ⁶⁸Ga-PSMA PET positive lesions is associated with higher levels of PSA and shorter PSA DT, thus representing potential prognostic factors.

How to optimize follow-up in patients with a suspicious multiparametric MRI and a subsequent negative targeted prostate biopsy. Results from a large, single-institution series

OBJECTIVE

We aimed at optimizing the follow-up for patients with a positive multiparametric magnetic resonance of the prostate (mpMRI) and a subsequent negative targeted biopsy (TBx) plus systematic biopsy (SBx).

MATERIALS AND METHODS

A total of 308 men with a clinical suspicion of PCa and a positive mpMRI (PI-RADS ≥ 3) with concomitant negative systematic and targeted Bx performed at a single tertiary referral center. All patients were then followed with serial PSA measurements, digital rectal examination and eventual follow-up mpMRI and/or repeat Bx. The primary outcome was to evaluate the overall clinically significant PCa (csPCa)-free survival. The secondary outcome was to assess the role of a repeat mpMRI (Fu-mpMRI) and PSA density as predictors of csPCa diagnosis (defined as Gleason score ≥ 3 + 4) during follow-up. Kaplan Meier analysis and univariable Cox regression were used for survival and predictive analyses.

RESULTS

Median follow-up was 31 months (IQR: 23-43). During the study period 116 (37.7%) and 68 (22.1%) of men received a Fu-mpMRI and a Fu-Bx, respectively. Overall, 51 (16.6%) and 15 (4.9%) patients had a positive mpMRI and clinically significant (csPCa) diagnosis during follow-up, respectively. Among 68 men who received a Fu-Bx, the 2- and 3-years csPCa diagnosis-free survival in men with negative vs. positive Fu-mpMRI was 97% vs. 65% and 92% vs. 65%, respectively. At univariate Cox-regression analysis the presence of a positive Fu-mpMRI resulted to be significantly associated with the presence of csPCa at Fu-Bx (HR: 5.8, 95% CI: 1.3-26.6, P = 0.008). The 2- and 3-years csPCa diagnosis-free survival in men with PSAd <0.15 vs. ≥0.15 was 89% vs. 77%, and 86% vs. 66%, respectively (HR: 2.6, 95% CI: 0.75-8.87, P = 0.13). The combination of negative Fu-mpMRI and PSAd<0.15 furtherly reduced the probability of csPCa diagnosis at Fu-Bx at only 6% at 3years (HR: 9.9, 95% CI: 1.9-38.6, P < 0.001) in this subgroup of patients.

CONCLUSIONS

After a negative TBx for a positive mpMRI, more than half of Fu-mpMRI were negative. A persistent positive mpMRI was associated with a significant risk of csPCa. The risk of csPCa diagnosis in men with negative mpMRI performed after negative TBx and low PSAd was negligible.

ReIMAGINE Prostate Cancer Screening Study: protocol for a single-centre feasibility study inviting men for prostate cancer screening using MRI

INTRODUCTION

The primary objective of the ReIMAGINE Prostate Cancer Screening Study is to explore the uptake of an invitation to prostate cancer screening using MRI.

METHODS AND ANALYSIS

The ReIMAGINE Prostate Cancer Screening Study is a prospective single-centre feasibility study. Eligible men aged 50-75 years with no prior prostate cancer diagnosis or treatment will be identified through general practitioner practices and randomly selected for invitation. Those invited will be offered an MRI scan and a prostate-specific antigen (PSA) blood test. The screening MRI scan consists of T2-weighted, diffusion-weighted and research-specific sequences, without the use of intravenous contrast agents. Men who screen positive on either MRI or PSA density will be recommended to have standard of care (National Health Service) tests for prostate cancer assessment, which includes multiparametric MRI. The study will assess the acceptability of an MRI-based prostate screening assessment and the prevalence of cancer detected in MRI-screened men. Summary statistics will be used to explore baseline characteristics in relation to acceptance rates and prevalence of cancer.

ETHICS AND DISSEMINATION

ReIMAGINE Prostate Cancer Screening is a single-site screening study to assess the feasibility of MRI as a screening tool for prostate cancer. Ethical approval was granted by London-Stanmore Research Ethics Committee Heath Research Authority (reference 19/LO/1129). Study results will be published in peer-reviewed journals after completion of data analysis and used to inform the design of a multicentre screening study in the UK.

TRIAL REGISTRATION NUMBER

ClinicalTrials.gov Registry (NCT04063566).