The Transatlantic Recommendations for Prostate Gland Evaluation with Magnetic Resonance Imaging After Focal Therapy (TARGET): A Systematic Review and International Consensus Recommendations.

BACKGROUND AND OBJECTIVE: Magnetic resonance imaging (MRI) can detect recurrences after focal therapy for prostate cancer but there is no robust guidance regarding its use. Our objective was to produce consensus recommendations on MRI acquisition, interpretation, and reporting after focal therapy. METHODS: A systematic review was performed in July 2022 to develop consensus statements. A two-round consensus exercise was then performed, with a consensus meeting in January 2023, during which 329 statements were scored by 23 panellists from Europe and North America spanning urology, radiology, and pathology with experience across eight focal therapy modalities. Using RAND Corporation/University of California-Los Angeles methodology, the Transatlantic Recommendations for Prostate Gland Evaluation with MRI after Focal Therapy (TARGET) were based on consensus for statements scored with agreement or disagreement. KEY FINDINGS AND LIMITATIONS: In total, 73 studies were included in the review. All 20 studies (100%) reporting suspicious imaging features cited focal contrast enhancement as suspicious for cancer recurrence. Of 31 studies reporting MRI assessment criteria, the Prostate Imaging-Reporting and Data System (PI-RADS) score was the scheme used most often (20 studies; 65%), followed by a 5-point Likert score (six studies; 19%). For the consensus exercise, consensus for statements scored with agreement or disagreement increased from 227 of 295 statements (76.9%) in round one to 270 of 329 statements (82.1%) in round two. Key recommendations include performing routine MRI at 12 mo using a multiparametric protocol compliant with PI-RADS version 2.1 standards. PI-RADS category scores for assessing recurrence within the ablation zone should be avoided. An alternative 5-point scoring system is presented that includes a major dynamic contrast enhancement (DCE) sequence and joint minor diffusion-weighted imaging and T2-weighted sequences. For the DCE sequence, focal nodular strong early enhancement was the most suspicious imaging finding. A structured minimum reporting data set and minimum reporting standards for studies detailing MRI data after focal therapy are presented. CONCLUSIONS AND CLINICAL IMPLICATIONS: The TARGET consensus recommendations may improve MRI acquisition, interpretation, and reporting after focal therapy for prostate cancer and provide minimum standards for study reporting. PATIENT SUMMARY: Magnetic resonance imaging (MRI) scans can detect recurrent of prostate cancer after focal treatments, but there is a lack of guidance on MRI use for this purpose. We report new expert recommendations that may improve practice.

Declutter the MRI protocol tree: Managing and comparing sequence parameters of multiple clinical Siemens MRI systems.

An MRI protocol tree on a clinical MRI system is a large database containing hundreds of protocols, each containing multiple sequences, and up to 900 parameters per sequence. Protocol variation between scan sessions or patients must be avoided as much as possible, as it may lead to financial loss and less than optimal outcomes for the patient. Without proper management, protocol variation and errors in MRI protocol trees are easily introduced and may remain undetected, leading to a cluttered protocol tree. This in turn reduces the efficiency of the radiological MRI workflow. We introduce a method and open-source software tools for managing MRI protocols on a sequence parameter level, which can detect deviations and variations in the protocol tree. It can be used offline, away from the scanner console, without disturbing the clinical workflow. These tools help to create a standardized protocol library across multiple MRI scanners, reducing variation and errors, enabling radiology departments to create optimal value for the patient and institution.

Performance of MRI for Detection of ≥pT1b Disease in Local Staging of Endometrial Cancer.

Magnetic resonance imaging (MRI) can be used for the preoperative local staging of endometrial cancer (EC). The presence of ≥pT1b disease (i.e., tumor invasion in ≥50% of the myometrium, into the cervical stroma or spread outside the uterus) has important prognostic value and implications for the decision to perform lymphadenectomy. The purpose of this study was to assess the performance of MRI for the detection of ≥pT1b disease and to evaluate whether tumor size measured via MRI was predictive for ≥pT1b disease, independent of imaging signs of deep invasion. MRI T-staging and tumor diameter and volume were correlated with histopathology of the hysterectomy specimen in 126 patients. MRI had a sensitivity, specificity, positive predictive value, negative predictive value and accuracy of 70.0%, 83.3%, 79.2%, 75.3% and 77.0%, respectively, for the detection of ≥pT1b disease. A tumor diameter of ≥40 mm and volume of ≥20 mL measured via MRI were predictive for ≥pT1b disease at rates of 78.3% and 87.1%, respectively. An EC size of at least 5 mm upon MRI was predictive for ≥pT1b disease in more than 50% of cases. Our results support the use of MRI in the preoperative staging of EC and suggest including size criteria in EC staging guidelines.

Risk Biomarkers for Biochemical Recurrence after Radical Prostatectomy for Prostate Cancer Using Clinical and MRI-Derived Semantic Features.

OBJECTIVES: This study aimed to assess the impact of the covariates derived from a predictive model for detecting extracapsular extension on pathology (pECE+) on biochemical recurrence-free survival (BCRFS) within 4 years after robotic-assisted radical prostatectomy (RARP). METHODS: Retrospective data analysis was conducted from a single center between 2015 and 2022. Variables under consideration included prostate-specific antigen (PSA) levels, patient age, prostate volume, MRI semantic features, and Grade Group (GG). We also assessed the influence of pECE+ and positive surgical margins on BCRFS. To attain these goals, we used the Kaplan-Meier survival function and the multivariable Cox regression model. Additionally, we analyzed the MRI features on BCR (biochemical recurrence) in low/intermediate risk patients. RESULTS: A total of 177 participants with a follow-up exceeding 6 months post-RARP were included. The 1-year, 2-year, and 4-year risks of BCR after radical prostatectomy were 5%, 13%, and 21%, respectively. The non-parametric approach for the survival analysis showed that adverse MRI features such as macroscopic ECE on MRI (mECE+), capsular disruption, high tumor capsular contact length (TCCL), GG ≥ 4, positive surgical margins (PSM), and pECE+ on pathology were risk factors for BCR. In low/intermediate-risk patients (pECE- and GG < 4), the presence of adverse MRI features has been shown to increase the risk of BCR. CONCLUSIONS: The study highlights the importance of incorporating predictive MRI features for detecting extracapsular extension pre-surgery in influencing early outcomes and clinical decision making; mECE+, TCCL, capsular disruption, and GG ≥ 4 based on pre-surgical biopsy were independent prognostic factors for early BCR. The presence of adverse features on MRI can assist in identifying low/intermediate-risk patients who will benefit from closer monitoring.

Clinical Application of the Prostate Cancer Radiological Estimation of Change in Sequential Evaluation Score for Reporting Magnetic Resonance Imaging in Men on Active Surveillance for Prostate Cancer.

Background: The Prostate Cancer Radiological Estimation of Change in Sequential Evaluation (PRECISE) score has been developed to standardise prostate magnetic resonance imaging (MRI) reporting in men on active surveillance (AS) for prostate cancer (PCa). Objective: To evaluate the feasibility of PRECISE scoring and assess its diagnostic accuracy. Design setting and participants: All PCa patients on AS with a baseline MRI and at least one follow-up MRI scan between January 2008 and September 2022 at a single tertiary referral centre were included in a database. The follow-up protocol of the Prostate Cancer International Active Surveillance (PRIAS) study was used. All scans were retrospectively re-reported by a dedicated uroradiologist and appointed a Prostate Imaging Reporting and Data System (version 2.1) and PRECISE score. Outcome measurements and statistical analysis: Clinically significant progression was defined by histopathological upgrading (on biopsy or radical prostatectomy) to grade group ≥3 and/or evolution to T3 stage. A survival analysis was performed to assess differential progression-free survival (PFS) according to the PRECISE score. Results and limitations: A total of 188 patients were included for an analysis with a total of 358 repeat MRI scans and 144 repeat biopsies. The median follow-up was 46 mo (interquartile range 21-74). Radiological progression (PRECISE 4-5) had sensitivity, specificity, negative predictive value, and positive predictive value of, respectively, 78%, 70%, 90%, and 49% for clinically significant progression. Four-year PFS was 91% for PRECISE 1-3 versus 66% for PRECISE 4-5 (p < 0.001). In total, 137 patients underwent a confirmation MRI scan within 18 mo after diagnosis. Four-year PFS in this group was 81% for PRECISE 1-3 versus 43% for PRECISE 4-5 (p < 0.001). Limitations include retrospective design and no strict adherence to AS protocol. Conclusions: Implementation of PRECISE scoring for PCa patients on AS is feasible and offers a prognostic value. Patients with PRECISE score 4-5 on confirmation MRI within 18 mo after diagnosis have a three-fold higher risk of clinically significant progression after 4 yr. Patient summary: Patients with low-risk prostate cancer can be followed up carefully. In this study, we evaluate the standardised reporting of repeat magnetic resonance imaging scans (using the Prostate Cancer Radiological Estimation of Change in Sequential Evaluation [PRECISE] recommendations). PRECISE scoring is feasible and helps identify patients in need of further treatment.

MRI texture analysis of T2-weighted images is preferred over magnetization transfer imaging for readily longitudinal quantification of gut fibrosis.

OBJECTIVES: To investigate the value of magnetization transfer (MT) MRI and texture analysis (TA) of T2-weighted MR images (T2WI) in the assessment of intestinal fibrosis in a mouse model. METHODS: Chronic colitis was induced in mice by cyclic administration of dextran sodium sulphate (DSS) resulting in chronic inflammation and progressive bowel fibrosis. Mice underwent 7-T MR imaging at various time points. Bowel wall MT ratio (MTR) and textural features (skewness, kurtosis, entropy), extracted by a filtration histogram technique, were correlated with histopathology. Performance of both techniques were validated using antifibrotic therapy. Finally, a retrospective study was conducted in five patients with Crohn's disease (CD) who underwent bowel surgery. RESULTS: MTR and texture entropy correlated with histopathological fibrosis (r = .85 and .81, respectively). Entropy was superior to MTR for monitoring bowel fibrosis in the presence of coexisting inflammation (linear regression R2 = .93 versus R2 = .01). Furthermore, texture entropy was able to assess antifibrotic therapy response (placebo mice versus treated mice at endpoint scan; Δmean = 0.128, p < .0001). An increase in entropy was indicative of fibrosis accumulation in human CD strictures (inflammation: 1.29; mixed strictures: 1.4 and 1.48; fibrosis: 1.73 and 1.9). CONCLUSION: MT imaging and TA of T2WI can both noninvasively detect established intestinal fibrosis in a mouse model. However, TA is especially useful for the longitudinal quantification of fibrosis in mixed inflammatory-fibrotic tissue, as well as for antifibrotic treatment response evaluation. This accessible post-processing technique merits further validation as the benefits for clinical practice as well as antifibrotic trial design would be numerous. KEY POINTS: • Magnetization transfer MRI and texture analysis of T2-weighted MR images can detect established bowel fibrosis in an animal model of gut fibrosis. • Texture entropy is able to identify and monitor bowel fibrosis progression in an inflammatory context and can assess the response to antifibrotic treatment. • A proof-of-concept study in five patients with Crohn's disease suggests that texture entropy can detect and grade fibrosis in human intestinal strictures.

The Changing Landscape of Systemic Therapy in the Treatment of Synchronous Metastatic Hormone-sensitive Prostate Cancer.

INTRODUCTION: To describe the changes in systemic treatments (ST) of synchronous metastatic hormone-sensitive prostate cancer (mHSPC) patients in a "real-world" setting and to explore reasons why contemporary standard of care (SOC) was not administrated to the patient. PATIENTS AND METHODS: Since 2014, we prospectively register mHSPCpatients. Patients were grouped in 4 time periods: group 1 (Time period 1, January 2014-July 2015), group 2 after introduction of docetaxel (Time period 2, August 2015-July 2017), group 3 after introduction of abiraterone acetate (Time period 3, August 2017-February 2018) and group 4 after introduction of apalutamide (Time period 4, March 2018-October 2021). For every time period, we evaluated the initiated additional ST. In case patients received treatment that differed from contemporary SOC according to guidelines, reasons for this difference were explored. RESULTS: In total, 243 patients were included. A progressive decline in ADT monotherapy from 85% to 29% over time was observed. The proportion of patients receiving additional STs increased from 34% to 59%. Forty percent of patients were not treated according to contemporary SOC, but this percentage varied strongly per time period (10%, 67%, 53%, and 32% from time period 1 to time period 4 respectively). Reasons for these variations were heterogenous and varied across the 4 time periods. Patients being unfit for treatment and treating physicians failing to consider additional STs were the most prevalent reasons. The proportion of patients unfit for additional ST decreased from 18% to 4% over time. CONCLUSION: Use of ADT monotherapy declined gradually after the introduction of additional systemic treatments. The proportion of patients unfit for additional ST declined as more treatments became available. Although compliance to SOC increased over time, these real-world data show that adherence to clinical practice guidelines remains suboptimal. Efforts should be made by clinicians to increase the adherence to practice guidelines.

Long-Term Outcomes and Genetic Predictors of Response to Metastasis-Directed Therapy Versus Observation in Oligometastatic Prostate Cancer: Analysis of STOMP and ORIOLE Trials.

Clinical trials frequently include multiple end points that mature at different times. The initial report, typically based on the primary end point, may be published when key planned co-primary or secondary analyses are not yet available. Clinical Trial Updates provide an opportunity to disseminate additional results from studies, published in JCO or elsewhere, for which the primary end point has already been reported.The initial STOMP and ORIOLE trial reports suggested that metastasis-directed therapy (MDT) in oligometastatic castration-sensitive prostate cancer (omCSPC) was associated with improved treatment outcomes. Here, we present long-term outcomes of MDT in omCSPC by pooling STOMP and ORIOLE and assess the ability of a high-risk mutational signature to risk stratify outcomes after MDT. The primary end point was progression-free survival (PFS) calculated using the Kaplan-Meier method. High-risk mutations were defined as pathogenic somatic mutations within ATM, BRCA1/2, Rb1, or TP53. The median follow-up for the whole group was 52.5 months. Median PFS was prolonged with MDT compared with observation (pooled hazard ratio [HR], 0.44; 95% CI, 0.29 to 0.66; P value < .001), with the largest benefit of MDT in patients with a high-risk mutation (HR high-risk, 0.05; HR no high-risk, 0.42; P value for interaction: .12). Within the MDT cohort, the PFS was 13.4 months in those without a high-risk mutation, compared with 7.5 months in those with a high-risk mutation (HR, 0.53; 95% CI, 0.25 to 1.11; P = .09). Long-term outcomes from the only two randomized trials in omCSPC suggest a sustained clinical benefit to MDT over observation. A high-risk mutational signature may help risk stratify treatment outcomes after MDT.

Diagnostic Accuracy and Observer Agreement of the MRI Prostate Imaging for Recurrence Reporting Assessment Score.

Background Prostate cancer local recurrence location and extent must be determined in an accurate and timely manner. Because of the lack of a standardized MRI approach after whole-gland treatment, a panel of international experts recently proposed the Prostate Imaging for Recurrence Reporting (PI-RR) assessment score. Purpose To determine the diagnostic accuracy of PI-RR for detecting local recurrence in patients with biochemical recurrence (BCR) after radiation therapy (RT) or radical prostatectomy (RP) and to evaluate the interreader variability of PI-RR scoring. Materials and Methods This retrospective observational study included patients who underwent multiparametric MRI between September 2016 and May 2021 for BCR after RT or RP. MRI scans were analyzed, and a PI-RR score was assigned independently by four radiologists. The reference standard was defined using histopathologic findings, follow-up imaging, or clinical response to treatment. Sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy were calculated to assess PI-RR performance for each reader. The intraclass correlation coefficient was used to determine interreader agreement. Results A total of 100 men were included: 48 patients after RT (median age, 76 years [IQR, 70-82 years]) and 52 patients after RP (median age, 70 years [IQR, 66-74 years]). After RT, with PI-RR of 3 or greater as a cutoff (assigned when recurrence is uncertain), diagnostic performance ranges were 71%-81% sensitivity, 74%-93% specificity, 71%-89% PPV, 79%-86% NPV, and 77%-88% accuracy across the four readers. After RP, with PI-RR of 3 or greater as a cutoff, performance ranges were 59%-83% sensitivity, 87%-100% specificity, 88%-100% PPV, 66%-80% NPV, and 75%-85% accuracy. The intraclass correlation coefficient was 0.87 across the four readers for both the RT and RP groups. Conclusion MRI scoring with the Prostate Imaging for Recurrence Reporting assessment provides structured, reproducible, and accurate evaluation of local recurrence after definitive therapy for prostate cancer. © RSNA, 2022 Online supplemental material is available for this article. See also the editorial by Haider in this issue. An earlier incorrect version appeared online. This article was corrected on May 11, 2022.

Cavitary Lung Metastases in Prostate Cancer.

Teaching Point: Adenocarcinomas very rarely cause cavitary lung metastases.

A Curriculum Model for Multidisciplinary Training of Midwife Sonographers in a Low Resource Setting.

In many low-resource settings, less than 5% of pregnant women can access ultrasound during pregnancy. Thus, gestational age is often difficult to determine, multiple pregnancies are diagnosed late and foetal and pregnancy-related anomalies can go undetected. A pilot solution was designed beyond the traditional approach of increasing numbers of qualified radiologists, gynaecologists and sonographers. An innovative Human Resource for Health (HRH) task sharing, and maternal child health (MCH) workforce training and capacity building initiative was designed, involving development and testing of a curriculum to train midwife sonographers via a teleradiology innovation platform and a partnership between specialist radiologists, sonographers and midwives. The setting was a tertiary-level private university hospital in Nairobi with implementation in three outreach locations. Direct oversight, support and supervision of specialist radiologists and ultrasonographers effectively addressed issues of quality and safety across the 3-week training period and project implementation. Concepts from sociocultural learning theory informed an initial interactive e-learning module for each midwife at their respective site. Midwives were introduced to ultrasound equipment with a series of didactic and interactive lectures delivered by an expert sonographer at the tertiary hospital teaching site. Lectures were supported by hands-on practical experience, role modelling and mentoring over a four-week period. Assessments included both written examination and practical assessment with an exit examination requiring demonstration of competency in both written and practical format. Final confirmation of scanning accuracy was confirmed with post-delivery verification of results. The pilot was highly successful with an image interpretation accuracy of 99.63% for the midwives. Lessons from this initiative provides guidance in the curriculum development process along with a curriculum outline; pedagogical framework; teaching methods; assessment processes; credentialing; resourcing; and other considerations in scaling up the program. Importantly, the paper details processes for maintaining a high level of quality control and patient safety.

Evaluating the impact of 18F-FDG-PET-CT on risk stratification and treatment adaptation for patients with muscle-invasive bladder cancer (EFFORT-MIBC): a phase II prospective trial.

BACKGROUND: The outcome of patients with muscle-invasive bladder cancer (MIBC) remains poor, despite aggressive treatments. Inadequate primary staging, classically performed by computed tomography (CT)-imaging, could lead to inappropriate treatment and might contribute to these poor results. Although not (yet) adapted by international guidelines, several reports have indicated the superiority of 18F-fluorodeoxyglucose-positron emission tomography-CT (18F-FDG-PET-CT) compared to CT in the detection of lymph node and distant metastases. Thereby the presence of extra-vesical disease on 18F-FDG-PET-CT has been correlated with a worse overall survival. This supports the hypothesis that 18F-FDG-PET-CT is useful in stratifying MIBC patients and that adapting the treatment plan accordingly might result in improved outcome. METHODS: EFFORT-MIBC is a multicentric prospective phase II trial aiming to include 156 patients. Eligible patients are patients with histopathology-proven MIBC or ≥ T3 on conventional imaging treated with MIBC radical treatment, without extra-pelvic metastases on conventional imaging (thoracic CT and abdominopelvic CT/ magnetic resonance imaging (MRI)). All patients will undergo radical local therapy and if eligible neo-adjuvant chemotherapy. An 18F-FDG-PET-CT will be performed in addition to and at the timing of the conventional imaging. In case of presence of extra-pelvic metastasis on 18F-FDG-PET-CT, appropriate intensification of treatment with metastasis-directed therapy (MDT) (in case of ≤3 metastases) or systemic immunotherapy (> 3 metastases) will be provided. The primary outcome is the 2-year overall survival rate. Secondary endpoints are progression-free survival, distant metastasis-free survival, disease-specific survival and quality of life. Furthermore, the added diagnostic value of 18F-FDG-PET-CT compared to conventional imaging will be evaluated and biomarkers in tumor specimen, urine and blood will be correlated with primary and secondary endpoints. DISCUSSION: This is a prospective phase II trial evaluating the impact of 18F-FDG-PET-CT in stratifying patients with primary MIBC and tailoring the treatment accordingly. We hypothesize that the information on the pelvic nodes can be used to guide local treatment and that the presence of extra-pelvic metastases enables MDT or necessitates the early initiation of immunotherapy leading to an improved outcome. TRIAL REGISTRATION: The Ethics Committee of the Ghent University Hospital (BC-07456) approved this study on 11/5/2020. The trial was registered on ClinicalTrials.gov (NCT04724928) on 21/1/2021.

The Role of Cytoreductive Radical Prostatectomy in the Treatment of Newly Diagnosed Low-volume Metastatic Prostate Cancer. Results from the Local Treatment of Metastatic Prostate Cancer (LoMP) Registry.

BACKGROUND: Radiotherapy to the prostate (RTp) prolongs survival for patients with low-volume, newly diagnosed metastatic prostate cancer (ndmPC). OBJECTIVE: to evaluate whether cytoreductive radical prostatectomy (cRP) is equally beneficial as RTp in low-volume ndmPC. DESIGN SETTING AND PARTICIPANTS: A multicenter prospective registry was established in 2014 to observe patients with ndmPC. Eligible patients were offered cRP or RTp. For this study we selected only patients with low-volume ndmPC (n = 109). Of these, 48, 26, and 35 patients underwent cRP, RTp, and no local therapy (NLT), respectively. Median follow-up was 32 mo (interquartile range 16-49). INTERVENTION: cRP was compared with RTp and NLT. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: Overall survival (OS), cancer-specific survival (CSS), and local event-free survival (LEFS) were calculated using the Kaplan-Meier method. Factors prognostic for OS were identified using univariate and multivariate Cox regression analysis. RESULTS AND LIMITATIONS: The 2-yr OS was 93%, 100%, and 69%, and 2-yr CSS was 93%, 100%, and 75% for cRP, RTp, and NLT, respectively. The cRP and RTp groups had better OS compared to NLT and there was no significant difference between cRP and RTp. The 2-yr LEFS was 92%, 77%, and 60% for cRP, RTp, and NLT, respectively. The cRP group had better LEFS compared to RTp and NLT, and there was no significant difference between RTp and NLT. Advanced tumor stage, Eastern Cooperative Oncology Group performance status ≥2, and NLT were negative prognostic factors for OS. The main limitation is selection of fitter patients with less advanced tumors for cRP and the small sample size. CONCLUSIONS: For selected patients with low-volume ndmPC, cRP is able to achieve similar OS and CSS to RTp. cRP is effective in preventing local events due to disease progression. PATIENT SUMMARY: Patients with a low volume of newly diagnosed prostate cancer that has spread beyond the prostate gland might benefit from removal of the prostate, which we found was as effective as radiotherapy to the prostate in prolonging survival. Removal of the prostate is effective in preventing urinary problems caused by cancer progression.

ESUR/ESUI position paper: developing artificial intelligence for precision diagnosis of prostate cancer using magnetic resonance imaging.

Artificial intelligence developments are essential to the successful deployment of community-wide, MRI-driven prostate cancer diagnosis. AI systems should ensure that the main benefits of biopsy avoidance are delivered while maintaining consistent high specificities, at a range of disease prevalences. Since all current artificial intelligence / computer-aided detection systems for prostate cancer detection are experimental, multiple developmental efforts are still needed to bring the vision to fruition. Initial work needs to focus on developing systems as diagnostic supporting aids so their results can be integrated into the radiologists' workflow including gland and target outlining tasks for fusion biopsies. Developing AI systems as clinical decision-making tools will require greater efforts. The latter encompass larger multicentric, multivendor datasets where the different needs of patients stratified by diagnostic settings, disease prevalence, patient preference, and clinical setting are considered. AI-based, robust, standard operating procedures will increase the confidence of patients and payers, thus enabling the wider adoption of the MRI-directed approach for prostate cancer diagnosis. KEY POINTS: • AI systems need to ensure that the benefits of biopsy avoidance are delivered with consistent high specificities, at a range of disease prevalence. • Initial work has focused on developing systems as diagnostic supporting aids for outlining tasks, so they can be integrated into the radiologists' workflow to support MRI-directed biopsies. • Decision support tools require a larger body of work including multicentric, multivendor studies where the clinical needs, disease prevalence, patient preferences, and clinical setting are additionally defined.

Prostate Magnetic Resonance Imaging for Local Recurrence Reporting (PI-RR): International Consensus -based Guidelines on Multiparametric Magnetic Resonance Imaging for Prostate Cancer Recurrence after Radiation Therapy and Radical Prostatectomy.

BACKGROUND: Imaging techniques are used to identify local recurrence of prostate cancer (PCa) for salvage therapy and to exclude metastases that should be addressed with systemic therapy. For magnetic resonance imaging (MRI), a reduction in the variability of acquisition, interpretation, and reporting is required to detect local PCa recurrence in men with biochemical relapse after local treatment with curative intent. OBJECTIVE: To propose a standardised method for image acquisition and assessment of PCa local recurrence using MRI after radiation therapy (RP) and radical prostatectomy (RT). EVIDENCE ACQUISITION: Prostate Imaging for Recurrence Reporting (PI-RR) was formulated using the existing literature. An international panel of experts conducted a nonsystematic review of the literature. The PI-RR system was created via consensus through a combination of face-to-face and online discussions. EVIDENCE SYNTHESIS: Similar to with PI-RADS, based on the best available evidence and expert opinion, the minimum acceptable MRI parameters for detection of recurrence after radiation therapy and radical prostatectomy are set. Also, a simplified and standardised terminology and content of the reports that use five assessment categories to summarise the suspicion of local recurrence (PI-RR) are designed. PI-RR scores of 1 and 2 are assigned to lesions with a very low and low likelihood of recurrence, respectively. PI-RR 3 is assigned if the presence of recurrence is uncertain. PI-RR 4 and 5 are assigned for a high and very high likelihood of recurrence, respectively. PI-RR is intended to be used in routine clinical practice and to facilitate data collection and outcome monitoring for research. CONCLUSIONS: This paper provides a structured reporting system (PI-RR) for MRI evaluation of local recurrence of PCa after RT and RP. PATIENT SUMMARY: A new method called PI-RR was developed to promote standardisation and reduce variations in the acquisition, interpretation, and reporting of magnetic resonance imaging for evaluating local recurrence of prostate cancer and guiding therapy.

Contrast Medium or No Contrast Medium for Prostate Cancer Diagnosis. That Is the Question.

The benefits and drawbacks of the dynamic contrast-enhanced MRI sequence for prostate cancer diagnosis are increasingly being recognized, with many centers adopting the biparametric (bp) MRI approach as the default initial approach. The abandonment of the routine use of contrast medium requires an assessment of the loss of diagnostic power against the gains in operational logistics, costs, time, capacity, and side effects. It is the balance of these factors weighted against the clinical priorities of patients that determines which patient groups can safely avoid dynamic contrast enhancement. Although systematic reviews and individual studies are broadly supportive of the bpMRI approach, the pathway impacts for men with suspected cancer using the bpMRI approach are still not well documented for clinical practice. Robust prospectively acquired data for bpMRI regarding biopsy avoidance, detection of clinically significant and insignificant cancers, and for increasing the precision of tumor grade and volume are needed. There is a requirement for prospective, randomized, or blinded head-to-head, multicenter studies, addressing the noninferiority of biopsy yields prompted by bpMRI and multiparametric MRI approaches. These studies should more precisely define patient groups where the benefits and harms of contrast enhancement are aligned to their clinical priorities. Only then can we be confident in recommending bpMRI as an initial diagnostic approach for prostate cancer diagnosis. Level of Evidence 1 Technical Efficacy Stage 5.

How does PI-RADS v2.1 impact patient classification? A head-to-head comparison between PI-RADS v2.0 and v2.1.

BACKGROUND: PI-RADS classification has recently been updated, with the magnitude of changes implemented currently unknown. PURPOSE: To quantify the categorization shifts between PI-RADS v2.0 and v2.1. MATERIAL AND METHODS: Retrospective review of 535 consecutive diagnostic magnetic resonance imaging (MRI) studies performed over 18 months, assigning to each case a PI-RADS category in the peripheral zone (PZ), the transition zone (TZ), and the whole gland using both PI-RADS v2.0 and v2.1. Significance of changes in category assignments and of differences in the number of positive or negative MRIs were evaluated using the McNemar test. RESULTS: Comparing v2.0 to v2.1 for the whole gland, 11.2% of PI-RADS 2 categories shifted to PI-RADS 1 (6.9% in the PZ, 56.8% in the TZ), 16.1% of PI-RADS 3 categories shifted to PI-RADS 2 (15.0% in the PZ, 20.0% in the TZ), and 2.1% of PI-RADS 2 categories shifted to PI-RADS 3 (0.3% in the PZ, 1.9% in the TZ). The proportion of PI-RADS 1 significantly increased from 0.6% to 7.3%, PI-RADS 2 significantly decreased from 60.0% to 53.8%, and PI-RADS 3 non-significantly decreased from 11.6% to 11.0%. The total number of positive exams (PI-RADS 3-5) did not change significantly (39.4% versus 38.8%). CONCLUSION: The most prominent change between v2.0 and v2.1 was observed in the TZ with the downgrading of typical benign prostatic hyperplasia nodules from category 2 into category 1. Overall, there were no significant changes in the number of positive and negative MRI results, with an expected low influence in clinical management.

PI-RADS Committee Position on MRI Without Contrast Medium in Biopsy-Naive Men With Suspected Prostate Cancer: Narrative Review.

The steadily increasing demand for diagnostic prostate MRI has led to concerns regarding the lack of access to and the availability of qualified MRI scanners and sufficiently experienced radiologists, radiographers, and technologists to meet the demand. Solutions must enhance operational benefits without compromising diagnostic performance, quality, and delivery of service. Solutions should also mitigate risks such as decreased reader confidence and referrer engagement. One approach may be the implementation of MRI without the use gadolinium-based contrast medium (bipara-metric MRI), but only if certain prerequisites such as high-quality imaging, expert interpretation quality, and availability of patient recall or on-table monitoring are mandated. Alternatively, or in combination, a clinical risk-based approach could be used for protocol selection, specifically, which biopsy-naive men need MRI with contrast medium (multiparametric MRI). There is a need for prospective studies in which biopsy decisions are made according to MRI without contrast enhancement. Such studies must define clinical and operational benefits and identify which patient groups can be scanned successfully without contrast enhancement. These higher-quality data are needed before the Prostate Imaging Reporting and Data System (PI-RADS) Committee can make evidence-based recommendations about MRI without contrast enhancement as an initial diagnostic approach for prostate cancer workup.