Site-specific concordance of targeted and systematic biopsy cores at the index lesion on multiparametric magnetic resonance: can we spare the double-tap?

PURPOSE: To define the impact of systematic biopsy (SB) cores directed in the same area of index lesion in patients undergoing targeted biopsy (TB) and SB for prostate cancer (PCa) suspicion. METHODS: We retrospectively analyzed data of biopsy-naïve patients with one single suspicious lesion at mpMRI who underwent TB plus SB at our institution between January 2015 and September 2021. A convenient sample of 336 patients was available for our analyses. The primary outcome was to evaluate the impact of overlapping SB cores directed to the index lesion at mpMRI. The secondary outcome was to evaluate the SB cores concordance in terms of highest Gleason Score Detection with TB cores. RESULTS: 56% of patients were found to have site-specific concordance. SB cores determined disease upgrade in 22.1% patients. Thirty-one (16.4%) site-concordant patients experienced upgrade through overlapping SB cores, while 149 (79.3%) had no benefit by SB cores, and 8 (4.3%) patients had the worst ISUP at TB cores. 50% of the patients with negative-TB were upgraded to insignificant PCa, and 17.5% was upgraded from negative to unfavorable-intermediate- or high-risk PCa. Overall, 14 (19.4%) patients were also upgraded from ISUP 1 on TB to csPCa, with 28.5% of these harboring high-risk PCa. In csPCas at TB, 9 (12.5%) patients were upgraded from intermediate- to high-risk disease by SB. CONCLUSIONS: TB alone consents to identify worst ISUP PCa in vast majority of patients scheduled for biopsy. A non-negligible number of patients are upgraded via-SB cores, including also index lesion overlapping cores. Omitting these cores might lead to a suboptimal patient management.

Percutaneous ablation or minimally invasive partial nephrectomy for cT1a renal masses? A propensity score-matched analysis.

OBJECTIVE: Local tumor ablation to treat small renal mass is increasing. The aim of the present study was to compare oncologic outcomes among patients with T1 renal mass treated with partial nephrectomy and local tumor ablation. METHODS: To reduce the inherent differences between patients undergoing laparoscopic or robot-assisted partial nephrectomy (n = 405) and local tumor ablation (n = 137), we used a 1:1 propensity score-matched analysis. Local tumor ablation consisted of radiofrequency ablation and cryoablation. Disease-free survival, overall survival and other causes mortality-free survival rates were estimated using the Kaplan-Meier method. Multivariable logistic regression and competing-risk regression models were used to identify predictors of complications, recurrence and other causes mortality, respectively. RESULTS: Partial nephrectomy had higher disease-free survival estimates, as compared with local tumor ablation (92.8% vs 80.4% at 5 years, P = 0.02), with no significant difference between radiofrequency ablation and cryoablation (P = 0.9). Ablation showed comparable overall survival estimates to partial nephrectomy (91% vs 95.8% at 5 years, P = 0.6). The 5-year recurrence rates were 7.9% versus 23.8% for patients aged ≤70 years, and 2.5% versus 11.9% for patients aged >70 years treated with partial nephrectomy and ablation, respectively; the 5-year other causes mortality rates were 0% and 2.2% for patients treated with partial nephrectomy and ablation aged ≤70 years, and 3% versus 10.9% for patients aged >70 years treated with partial nephrectomy and ablation, respectively. At multivariable analysis, ablation was associated with fewer complications (odds ratio 0.41; P = 0.01). At competing risks analysis, age (hazard ratio 0.96) and ablation (hazard ratio 4.56) were independent predictors of disease recurrence (all P ≤ 0.008). CONCLUSIONS: Local tumor ablation showed a higher risk of recurrence and lower risk of complications compared with partial nephrectomy, with comparable overall survival rates.

The impact of multiparametric MRI features to identify the presence of prevalent cribriform pattern in the peripheral zone tumors.

PURPOSE: To assess the role of the multiparametric Magnetic Resonance Imaging (mpMRI) in predicting the cribriform pattern in both the peripheral and transition zones (PZ and TZ) clinically significant prostate cancers (csPCas). MATERIAL AND METHODS: We retrospectively evaluated 150 patients who underwent radical prostatectomy for csPCa and preoperative mpMRI. Patients with negative (n = 25) and positive (n = 125) mpMRI, stratified according to the presence of prevalent cribriform pattern (PCP, ≥ 50%) and non-PCP (< 50%) at specimen, were included. Difference between the two groups were evaluated. Multivariate logistic regression was used to identify predictors of PCP among mpMRI parameters. The receiver operating characteristic (ROC) analysis was performed to evaluate the area under the curve (AUC) of apparent diffusion coefficient (ADC) and ADC ratio in detecting lesions harboring PCP. RESULTS: Considering 135 positive lesions at the mpMRI, 30 (22.2%) and 105 (77.8%) harbored PCP and non-PCP PCa. The PCP lesions had more frequently nodular morphology (83.3% vs 62.9%; p = 0.04) and significantly lower mean ADC value (0.87 ± 0.16 vs 0.95 ± 0.18; p = 0.03) and ADC ratio (0.52 ± 0.09 vs 0.60 ± 0.14; p = 0.003) when compared with non-PCP lesions. At univariate and multivariate analyses, mean ADC and ADC ratio resulted as independent predictors of the presence of the PCP of the PZ tumors(OR: 0.025; p = 0.03 and OR: 0.001; p = 0.004, respectively). At the ROC analysis, the AUC of mean ADC and ADC ratio to predict the presence of PCP in patients with PZ suspicious lesion at the mpMRI were 0.69 (95% CI 0.56-0.81P, p = 0.003) and 0.72 (95% CI 0.62-0.82P, p = 0.001), respectively. CONCLUSIONS: The mpMRI may correctly identify PCP tumors of the PZ and the mean ADC value and ADC ratio can predict the presence of the cribriform pattern in the PCa.

A novel pathway to detect muscle-invasive bladder cancer based on integrated clinical features and VI-RADS score on MRI: results of a prospective multicenter study.

PURPOSE: To determine the clinical, pathological, and radiological features, including the Vesical Imaging-Reporting and Data System (VI-RADS) score, independently correlating with muscle-invasive bladder cancer (BCa), in a multicentric national setting. METHOD AND MATERIALS: Patients with BCa suspicion were offered magnetic resonance imaging (MRI) before trans-urethral resection of bladder tumor (TURBT). According to VI-RADS, a cutoff of ≥ 3 or ≥ 4 was assumed to define muscle-invasive bladder cancer (MIBC). Trans-urethral resection of the tumor (TURBT) and/or cystectomy reports were compared with preoperative VI-RADS scores to assess accuracy of MRI for discriminating between non-muscle-invasive versus MIBC. Performance was assessed by ROC curve analysis. Two univariable and multivariable logistic regression models were implemented including clinical, pathological, radiological data, and VI-RADS categories to determine the variables with an independent effect on MIBC. RESULTS: A final cohort of 139 patients was enrolled (median age 70 [IQR: 64, 76.5]). MRI showed sensitivity, specificity, PPV, NPV, and accuracy for MIBC diagnosis ranging from 83-93%, 80-92%, 67-81%, 93-96%, and 84-89% for the more experienced readers. The area under the curve (AUC) was 0.95 (0.91-0.99). In the multivariable logistic regression model, the VI-RADS score, using both a cutoff of 3 and 4 (P < .0001), hematuria (P = .007), tumor size (P = .013), and concomitant hydronephrosis (P = .027) were the variables correlating with a bladder cancer staged as ≥ T2. The inter-reader agreement was substantial (k = 0.814). CONCLUSIONS: VI-RADS assessment scoring proved to be an independent predictor of muscle-invasiveness, which might implicate a shift toward a more aggressive selection approach of patients' at high risk of MIBC, according to a novel proposed predictive pathway.

Complicated pyelonephritis associated with chronic renal stone disease.

PURPOSE: This article reviews imaging manifestations of complicated pyelonephritis associated with chronic renal stones disease, in particular xanthogranulomatous pyelonephritis (XGP) and emphysematous pyelonephritis (EPN), as potential mimics of other renal diseases and malignances and provides helpful tips and differentiating features that may alert the radiologist to suspect a diagnosis of infection. MATERIALS AND METHODS: A retrospective review of the records from 6 adult patients (5 females and 1 male, mean age 72,3 years) with diagnosis of XGP associated with chronic nephrolithiasis and 7 adult patients (6 females and 1 male, mean age 59,3 years) with diagnosis of EPN associated with chronic nephrolithiasis from January 2010 to January 2020 was carried out. Computed tomography urography (CTU) with at least an unenhanced scan, and the parenchymal and excretory phases after contrast medium administration performed at our Teaching Hospital were included. When available images related to conventional radiography, ultrasound (US) and magnetic resonance imaging of the same patients, the comparison with CTU images was carried out. CONCLUSION: A possible diagnosis of XGP or EPN must always be taken into account when a pyelonephritis is associated with untreated kidney stones, especially whenever clinical presentation is atypical, current therapy is not effective and imaging shows features of dubious interpretation. Due to their rarity and atypical presentation, a multidisciplinary approach is required and an expert radiologist represents a key figure in the multidisciplinary team as he can help to differentiate between benign and malignant lesions and thus avoid unnecessary radical surgical procedures.

State-of-the-art imaging techniques in the management of preoperative staging and re-staging of prostate cancer.

We aimed to review the current state-of-the-art imaging methods used for primary and secondary staging of prostate cancer, mainly focusing on multiparametric magnetic resonance imaging and positron-emission tomography/computed tomography with new radiotracers. An expert panel of urologists, radiologists and nuclear medicine physicians with wide experience in prostate cancer led a PubMed/MEDLINE search for prospective, retrospective original research, systematic review, meta-analyses and clinical guidelines for local and systemic staging of the primary tumor and recurrence disease after treatment. Despite magnetic resonance imaging having low sensitivity for microscopic extracapsular extension, it is now a mainstay of prostate cancer diagnosis and local staging, and is becoming a crucial tool in treatment planning. Cross-sectional imaging for nodal staging, such as computed tomography and magnetic resonance imaging, is clinically useless even in high-risk patients, but is still suggested by current clinical guidelines. Positron-emission tomography/computed tomography with newer tracers has some advantage over conventional images, but is not cost-effective. Bone scan and computed tomography are often useless in early biochemical relapse, when salvage treatments are potentially curative. New imaging modalities, such as prostate-specific membrane antigen positron-emission tomography/computed tomography and whole-body magnetic resonance imaging, are showing promising results for early local and systemic detection. Newer imaging techniques, such as multiparametric magnetic resonance imaging, whole-body magnetic resonance imaging and positron-emission tomography/computed tomography with prostate-specific membrane antigen, have the potential to fill the historical limitations of conventional imaging methods in some clinical situations of primary and secondary staging of prostate cancer.

Can the multiphasic computed tomography be useful in the clinical management of small renal masses?

Background Small renal masses (SRMs; ≤4 cm) represent a challenging issue. Computed tomography (CT) is widely used for investigating renal tumors even if its ability to differentiate among the different subtypes has not yet been definitively established. Purpose To assess the potential role of the morphological features and angiodynamic behavior on multiphasic CT in the preoperative evaluation of SRMs. Material and Methods The CT images of 80 patients with SRMs who underwent surgical resection at our institution were retrospectively reviewed. The morphological features, the pattern, and the quantitative analysis of enhancement were assessed for each lesion and were correlated with the histological subtypes. Results Overall, 81 SRMs were evaluated. Final pathological examination showed 30 (37%) oncocytomas, 22 (27.2%) clear cell renal cell carcinomas (ccRCCs), 16 (19.8%) papillary RCCs (pRCCs), and 13 (16%) chromophobe RCCs (chRCCs). Of the morphological features, only necrosis was significantly associated with ccRCC ( P = 0.047). The analysis of enhancement allowed the identification of two groups of lesions, based on arterial behavior: hypervascular (oncocytomas/ccRCC) and hypovascular (chRCC/pRCC) lesions. A significant difference between the two groups in terms of degree of enhancement on CT phases was found ( P < 0.05); this was also confirmed by the receiver operating characteristic (ROC) analysis. Conclusion Except for necrosis, the morphological features are not useful in making a correct diagnosis in the case of SRMs. The angiodynamic behavior on multiphasic CT showed high accuracy in differentiating between hypovascular and hypervascular tumors; this differentiation could be useful for deciding on the most appropriate clinical management of SRMs.

Anterior Nutcracker Syndrome with Left Gonadal Vein Varicosities on Multiphasic Computed Tomography: An Unexpected Cause of Pyeloureteral Junction Obstruction.

The anterior nutcracker syndrome is defined by the compression of the left renal vein between the aorta and superior mesenteric artery, usually related to the occurrence of hematuria. We report the case of an uncommon complication of the nutcracker syndrome. A 75-year-old woman was referred to our institution for left flank pain without hematuria. Multiphasic computer tomography urography showed a condition of left renal vein entrapment between the aorta and superior mesenteric artery with the development of left gonadal vein varicosities at the level of the renal hilum; a pyeloureteral junction compression with dilation of the pyelocalyceal system coexisted. To our knowledge, this is the first report of the association between nutcracker syndrome and pyeloureteral junction obstruction.

Three Unusual Cases of Nutcracker Syndrome Caused by Increased Blood Flow within the Left Renal Vein.

Nutcracker syndrome (NCS) refers to the compression of the left renal vein (LRV) between the aorta and the superior mesenteric artery. It can cause both microscopic and gross haematuria, with or without flank pain. The diagnosis is often delayed in a majority of symptomatic patients. On the other hand, the use of CT in routine abdominal explorations has increased the detection of the compression of the LRV in healthy and asymptomatic patients, but its diagnostic value remains uncertain. In this paper, we report 3 cases of the NCS associated with an increased blood flow in the LRV, due to different conditions, which we believe could produce the appearance of clinical symptoms.

3D FIESTA pulse sequence for assessing renal artery stenosis: is it a reliable application in unenhanced magnetic resonance angiography?

OBJECTIVES: To assess the capability of the three-dimensional (3D) Fast Imaging Employing Steady-State Acquisition (FIESTA) sequence in evaluating renal artery stenosis (RAS). METHODS: We retrospectively analysed 79 patients referred for suspected RAS, examined by 3D FIESTA and contrast-enhanced magnetic resonance angiography (CE-MRA), using a 1.5T whole-body scanner. Image quality was assessed as well as the presence and grade of RAS. Patients with RAS ≥ 50% were evaluated for possible digital subtraction angiography (DSA). Sensitivity, specificity, negative predictive value (NPV), positive predictive value (PPV), and accuracy of 3D FIESTA were calculated with ROC analysis using CE-MRA and DSA as the standard of reference. RESULTS: A total of 186 renal arteries were assessed; 36 had RAS ≥ 50 % demonstrated by CE-MRA. Ten patients underwent DSA, for a total evaluation of 22 arteries. Sensitivity, specificity, NPV, PPV, and accuracy of 3D FIESTA were 91.7%, 100%, 98%, 100%, and 98%, respectively, as compared to CE-MRA, and 88.2%, 100%, 71.4%, 100%, and 91%, respectively, as compared to DSA. The area under the ROC curve (AUC) of 3D FIESTA as compared to CE-MRA and DSA was 0.958 and 0.941, respectively. CONCLUSIONS: Our study demonstrated the capability of the 3D FIESTA sequence in evaluating RAS, with high-quality images and good diagnostic accuracy. KEY POINTS: The 3D FIESTA sequence provides a robust evaluation of RAS. The 3D FIESTA sequence allows non-invasive evaluation of the renal arteries. The 3D FIESTA sequence could be a useful tool in evaluating RAS.

First case of 18F-FACBC PET/CT-guided salvage radiotherapy for local relapse after radical prostatectomy with negative 11C-Choline PET/CT and multiparametric MRI: New imaging techniques may improve patient selection.

We present the first case of salvage radiotherapy based on the results of 18F-FACBC PET/CT performed for a PSA relapse after radical prostatectomy. The patients underwent 11CCholine PET/CT and multiparametric MRI that were negative while 18F-FACBC PET/CT visualized a suspected local relapse confirmed by transrectal ultrasound-guided biopsy. No distant relapse was detected. Thus the patient was submitted to salvage radiotherapy in the prostatic fossa. After 20 months of follow-up, the PSA was undetectable and 18F-FACBC PET/CT was negative. Salvage radiotherapy after surgery, provided that it is administered at the earliest evidence of the biochemical relapse, may improve cancer control and favourably influence the course of disease as well as the adjuvant approach. New imaging techniques may increase the efficacy of the salvage radiotherapy thus helping in the selection of the patients. Preliminary clinical reports showed an improvement in the detection rate of 20-40% of 18F-FACBC in comparison with 11C-Choline for the detection of disease relapse after radical prostatecomy, rendering the 18F-FACBC the potential radiotracer of the future for prostate cancer.

Multiparametric Whole-Body MRI: A Game Changer in Metastatic Prostate Cancer.

Prostate cancer ranks among the most prevalent tumours globally. While early detection reduces the likelihood of metastasis, managing advanced cases poses challenges in diagnosis and treatment. Current international guidelines support the concurrent use of 99Tc-Bone Scintigraphy and Contrast-Enhanced Chest and Abdomen CT for the staging of metastatic disease and response assessment. However, emerging evidence underscores the superiority of next-generation imaging techniques including PSMA-PET/CT and whole-body MRI (WB-MRI). This review explores the relevant scientific literature on the role of WB-MRI in metastatic prostate cancer. This multiparametric imaging technique, combining the high anatomical resolution of standard MRI sequences with functional sequences such as diffusion-weighted imaging (DWI) and bone marrow relative fat fraction (rFF%) has proved effective in comprehensive patient assessment, evaluating local disease, most of the nodal involvement, bone metastases and their complications, and detecting the increasing visceral metastases in prostate cancer. It does have the advantage of avoiding the injection of contrast medium/radionuclide administration, spares the patient the exposure to ionizing radiation, and lacks the confounder of FLARE described with nuclear medicine techniques. Up-to-date literature regarding the diagnostic capabilities of WB-MRI, though still limited compared to PSMA-PET/CT, strongly supports its widespread incorporation into standard clinical practice, alongside the latest nuclear medicine techniques.

Diffusion tensor imaging and tractography of the kidneys: assessment of chronic parenchymal diseases.

OBJECTIVE: To assess renal dysfunction in chronic kidney diseases using diffusion tensor imaging (DTI). METHODS: Forty-seven patients with impaired renal function (study group) and 17 patients without renal diseases (control group) were examined using DTI sequences. Cortical and medullary regions of interest (ROIs) were located to obtain the corresponding values of the apparent diffusion coefficient (ADC) and the fractional anisotropy (FA). The mean values of the ADC and FA, for each ROI site, were obtained in each group and were compared. Furthermore, the correlations between the diffusion parameters and the estimated glomerular filtration rate (eGFR) were determined. RESULTS: In both the normal and affected kidneys, we obtained the cortico-medullary difference of the ADC and the FA values. The FA value in the medulla was significantly lower (P = 0.0149) in patients with renal function impairment as compared to patients with normal renal function. A direct correlation between DTI parameters and the eGFR was not found. Tractography visualised disruption of the regular arrangement of the tracts in patient with renal function alteration. CONCLUSION: DTI could be a useful tool in the evaluation of chronic kidney disease and, in particular, the medullary FA value seems to be the main parameter for assessing renal damage. KEY POINTS: • Magnetic resonance diffusion tensor imaging (MRDTI) provides new information about renal problems. • DTI allows non-invasive repeatable evaluation of the renal parenchyma, without contrast media. • DTI could become useful in the management of chronic parenchymal disease. • DTI seems more appropriate for renal evaluation than diffusion-weighted imaging.

Massive hematuria due to ruptured iatrogenic aortic pseudoaneurysm: a case report.

We report an interesting case of massive haematuria secondary to a rupture of a pseudoa- neurysm of the abdominal aorta below the renal vessels. A 65-year-old woman present- ed at our institution with a painful massive haematuria and anaemia. Two months before, she undergone a pelvic surgery complicated by an accidental injury of the right ureter sutured with a end-to-end anastomosis. An abdominal computed tomography (CT) scan with intravenous contrast showed a right-sided hydronephrosis with clots in the lumen of the right pelvis with a massive retroperitoneal hematoma due to a rupture of a iatrogenic pseudoaneurysm of the abdominal aorta below the origin of the renal arteries.

Case report: PSMA PET/CT addresses the correct diagnosis in a patient with metastatic prostate cancer despite negative core biopsies and mpMRI. A diagnostic challenge.

This is a case of [68 Ga]Ga-Prostate-specific membrane antigen (PSMA)-11 PET/CT in a 73-years old patient presenting high Prostate Specific Antigen (PSA) levels despite both multi-parametric magnetic resonance imaging (mpMRI) and 12-core saturation biopsy negative for prostate cancer (Pca). This is a highly interesting case because, despite the advanced metastatic spread at initial presentation as showed by [68Ga]Ga-PSMA-PET/CT, the primary Pca was detected by none of the diagnostic techniques (12 random sample biopsy, mpMRI, PSMA PET/CT). However, [68Ga]Ga-PSMA-PET/CT showed a suspicious axillary lesion suitable for biopsy, which finally resulted as Pca metastasis. This case report is therefore a brilliant example of how [68Ga]Ga-PSMA-PET/CT optimized patient's management.

Multiparametric magnetic resonance imaging for the differential diagnosis between granulomatous prostatitis and prostate cancer: a literature review to an intriguing diagnostic challenge.

Multiparametric magnetic resonance imaging (mpMRI) is currently the most effective diagnostic tool for detecting prostate cancer (PCa) and evaluating adenocarcinoma-mimicking lesions of the prostate gland, among which granulomatous prostatitis (GP) represents the most interesting diagnostic challenge. GP consists of a heterogeneous group of chronic inflammatory lesions that can be differentiated into four types: idiopathic, infective, iatrogenic, and associated with systemic granulomatous disease. The incidence of GP is growing due to the increase in endourological surgical interventions and the adoption of intravesical instillation of Bacillus Calmette-Guerin in patients with non-muscle invasive bladder cancer; therefore, the difficulty lies in identifying specific features of GP on mpMRI to avoid the use of transrectal prostate biopsy as much as possible.

Comparison of prostate cancer detection rate at targeted biopsy of hub and spoke centers mpMRI: experience matters.

BACKGROUND: Latest changes in European guidelines on prostate cancer determined a widespread of multiparametric magnetic resonance imaging (mpMRI) even in less experienced centers due to an increased demand. This could decrease diagnostic accuracy of targeted biopsy (TB) since image interpretation can be challenging and requires adequate and supervised training. Therefore we aimed to evaluate the prostate cancer (PCa) detection rate on TB according to mpMRI center's volume and experience. METHODS: We retrospectively analyzed data of 737 patients who underwent mpMRI-TB at our institution. Patients were stratified according to mpMRI center: Hub (high volume >100 exams/year with dedicated radiologists and supervised training) and Spoke center (low volume <100 exams/year without dedicated radiologists and/or supervised training). Detection rate of PCa at TB and possible predictors of clinically significant PCa (csPCa) at TB. Differences in detection rate were explored using Chi-square test. Predictors of csPCa were evaluated through uni and multivariable logistic regression. The adjustment for casemix included: age, PSA, mpMRI center, lesion's location, PSA density, PI-RADS score and index lesion's size. RESULTS: Four hundred forty-nine (60.9%) and 288 (39.1%) patients underwent mpMRI at a Hub or Spoke center, respectively. Hub group had higher detection rate for both any (60.3% vs. 48.1%) and csPCa (46.9% vs 38.7%; all P≤0.001). After stratifying for PI-RADS score, Hub group had higher detection rate for PI-RADS score 3 (csPCA 25.2% vs. 15.7%; p 0.04) and 4 (csPCa 65.7% vs. 45.7%; P=0.001). At multivariable analyses, receiving an mpMRI scan at a Spoke center was an independent predictor for csPCa on TB (OR 0.65; P=0.04). CONCLUSIONS: mpMRI performed in Hub centers provided a significantly higher PCa yield on TB. A dedicated team of experienced radiologist, a supervised training for mpMRI and a central revision of mpMRI performed in non-experienced centres are essential to avoid unnecessary and potentially harmful procedures.

Transverse prostate maximum sectional area can predict clinically significant prostate cancer in PI-RADS 3 lesions at multiparametric magnetic resonance imaging.

Background: To evaluate multiparametric magnetic resonance imaging (mpMRI) parameters, such as TransPA (transverse prostate maximum sectional area), TransCGA (transverse central gland sectional area), TransPZA (transverse peripheral zone sectional area), and TransPAI (TransPZA/TransCGA ratio) in predicting prostate cancer (PCa) in prostate imaging reporting and data system (PI-RADS) 3 lesions. Methods: Sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV), the area under the receiver operating characteristic curve (AUC), and the best cut-off, were calculated. Univariate and multivariate analyses were carried out to evaluate the capability to predict PCa. Results: Out of 120 PI-RADS 3 lesions, 54 (45.0%) were PCa with 34 (28.3%) csPCas. Median TransPA, TransCGA, TransPZA and TransPAI were 15.4cm2, 9.1cm2, 5.5cm2 and 0.57, respectively. At multivariate analysis, location in the transition zone (OR=7.92, 95% CI: 2.70-23.29, P<0.001) and TransPA (OR=0.83, 95% CI: 0.76-0.92, P<0.001) were independent predictors of PCa. The TransPA (OR=0.90, 95% CI: 0.082-0.99, P=0.022) was an independent predictor of csPCa. The best cut-off of TransPA for csPCa was 18 (Sensitivity 88.2%, Specificity 37.2%, PPV 35.7%, NPV 88.9%). The discrimination (AUC) of the multivariate model was 0.627 (95% CI: 0.519-0.734, P<0.031). Conclusions: In PI-RADS 3 lesions, the TransPA could be useful in selecting patients requiring biopsy.

An Apparent Diffusion Coefficient-Based Machine Learning Model Can Improve Prostate Cancer Detection in the Grey Area of the Prostate Imaging Reporting and Data System Category 3: A Single-Centre Experience.

The Prostate Imaging and Reporting Data System (PI-RADS) has a key role in the management of prostate cancer (PCa). However, the clinical interpretation of PI-RADS 3 score lesions may be challenging and misleading, thus postponing PCa diagnosis to biopsy outcome. Multiparametric magnetic resonance imaging (mpMRI) radiomic analysis may represent a stand-alone noninvasive tool for PCa diagnosis. Hence, this study aims at developing a mpMRI-based radiomic PCa diagnostic model in a cohort of PI-RADS 3 lesions. We enrolled 133 patients with 155 PI-RADS 3 lesions, 84 of which had PCa confirmation by fusion biopsy. Local radiomic features were generated from apparent diffusion coefficient maps, and the four most informative were selected using LASSO, the Wilcoxon rank-sum test (p < 0.001), and support vector machines (SVMs). The selected features where augmented and used to train an SVM classifier, externally validated on a holdout subset. Linear and second-order polynomial kernels were exploited, and their predictive performance compared through receiver operating characteristics (ROC)-related metrics. On the test set, the highest performance, equally for both kernels, was specificity = 76%, sensitivity = 78%, positive predictive value = 80%, and negative predictive value = 74%. Our findings substantially improve radiologist interpretation of PI-RADS 3 lesions and let us advance towards an image-driven PCa diagnosis.