Assessment of prostate cancer prognostic Gleason grade group using zonal-specific features extracted from biparametric MRI using a KNN classifier.

PURPOSE: To automatically assess the aggressiveness of prostate cancer (PCa) lesions using zonal-specific image features extracted from diffusion weighted imaging (DWI) and T2W MRI. METHODS: Region of interest was extracted from DWI (peripheral zone) and T2W MRI (transitional zone and anterior fibromuscular stroma) around the center of 112 PCa lesions from 99 patients. Image histogram and texture features, 38 in total, were used together with a k-nearest neighbor classifier to classify lesions into their respective prognostic Grade Group (GG) (proposed by the International Society of Urological Pathology 2014 consensus conference). A semi-exhaustive feature search was performed (1-6 features in each feature set) and validated using threefold stratified cross validation in a one-versus-rest classification setup. RESULTS: Classifying PCa lesions into GGs resulted in AUC of 0.87, 0.88, 0.96, 0.98, and 0.91 for GG1, GG2, GG1 + 2, GG3, and GG4 + 5 for the peripheral zone, respectively. The results for transitional zone and anterior fibromuscular stroma were AUC of 0.85, 0.89, 0.83, 0.94, and 0.86 for GG1, GG2, GG1 + 2, GG3, and GG4 + 5, respectively. CONCLUSION: This study showed promising results with reasonable AUC values for classification of all GG indicating that zonal-specific imaging features from DWI and T2W MRI can be used to differentiate between PCa lesions of various aggressiveness.

Multiparametric MRI in men with clinical suspicion of prostate cancer undergoing repeat biopsy: a prospective comparison with clinical findings and histopathology.

Background Multiparametric magnetic resonance imaging (mpMRI) can improve detection of clinically significant prostate cancer (csPCa). Purpose To compare mpMRI score subgroups to systematic transrectal ultrasound-guided biopsies (TRUSbx) and prostate-specific antigen (PSA)-based findings for detection of csPCa in men undergoing repeat biopsies. Material and Methods MpMRI was performed prior to re-biopsy in 289 prospectively enrolled patients. All underwent repeat TRUSbx followed by targeted biopsies (MRITB) of any mpMRI-identified lesion. MpMRI suspicion grade, PSA level, and density (PSAd) were compared with biopsy results and further matched to the radical prostatectomy (RP) specimen if available. Results PCa was detected in 128/289 (44%) patients with median age, PSA, and prior negative TRUSbx of 64 (interquartile range [IQR] = 59-67), 12.0 ng/mL (IQR = 8.3-19.1), and 2 (IQR = 1-3), respectively. TRUSbx detected PCa in 108/289 (37%) patients, of which 49 (45%) had insignificant cancer. MRITB was performed in 271/289 (94%) patients and detected PCa in 96 (35%) with 78 (81%) having csPCa. MpMRI scores showed a high association between suspicion level and biopsy results on both lesion and patient level ( P < 0.001). MpMRI was better than PSA and PSAd ( P < 0.001) to identify patients with missed csPCa. In total, 64/128 (50%) patients underwent RP; 60/64 had csPCa. MpMRI was significantly better in predicting csPCa on RP compared with TRUSbx ( P = 0.019) as MRITB and TRUSbx correctly identified 47/60 (78%) and 35/60 (58%) patients, respectively. Conclusion MpMRI improves detection of missed csPCa and suspicion scores correlate well with biopsy and RP results on both patient and lesion level.

Clinical Outcome Following Low Suspicion Multiparametric Prostate Magnetic Resonance Imaging or Benign Magnetic Resonance Imaging Guided Biopsy to Detect Prostate Cancer.

PURPOSE: We assessed the risk of significant prostate cancer being detected after low suspicion magnetic resonance imaging or suspicious magnetic resonance imaging with benign magnetic resonance imaging guided biopsies in men with prior negative systematic biopsies. MATERIALS AND METHODS: Overall 289 prospectively enrolled men underwent magnetic resonance imaging followed by repeat systematic and targeted biopsies of any suspicious lesions at baseline. A total of 194 patients with low suspicion magnetic resonance imaging or benign target biopsies were suitable for this study. Those who were negative for prostate cancer at baseline were followed for at least 3 years. We calculated the negative predictive values of magnetic resonance imaging in ruling out any prostate cancer and significant prostate cancer, defined as any core with Gleason score greater than 6, or more than 2 positive cores/cancerous core 50% or greater. RESULTS: Prostate cancer was detected in 38 of 194 (20%) patients during the median study period of 47 months (IQR 43-52). The overall negative predictive value of magnetic resonance imaging in ruling out any and significant prostate cancer was 80% (156 of 194) and 95% (184 of 194), respectively. No patient with low suspicion magnetic resonance imaging had intermediate/high grade cancer (Gleason score greater than 6). The majority of patients with no cancer during followup (132 of 156, 85%) had a decreasing prostate specific antigen and could be monitored in primary care. CONCLUSIONS: Low suspicion magnetic resonance imaging in men with prior negative systematic biopsies has a high negative predictive value in ruling out longer term, significant cancer. Therefore, immediate repeat biopsies are of limited clinical value and could be avoided even if prostate specific antigen is persistently increased.

A Prospective Comparison of Selective Multiparametric Magnetic Resonance Imaging Fusion-Targeted and Systematic Transrectal Ultrasound-Guided Biopsies for Detecting Prostate Cancer in Men Undergoing Repeated Biopsies.

INTRODUCTION: The aim of the study was to compare the prostate cancer (PCa) detection rate of systematic transrectal ultrasound-guided biopsies (TRUS-bx) and multiparametric-MRI targeted biopsies (mp-MRI-bx) in a repeat biopsy setting and evaluate the clinical significance following an "MRI-targeted-only" approach. MATERIALS AND METHODS: Patients with prior negative biopsies underwent prostatic multiparametric-MRI that was scored using the Prostate Imaging Reporting and Data System (PI-RADS) classification. All underwent both repeated TRUS-bx and mp-MRI-bx using image fusion of any PI-RADS ≥3 lesion. Biopsy results from TRUS-bx, mp-MRI-bx, and the combination were compared. RESULTS: PCa was detected in 89 out of 206 (43%) patients. Of these, 64 (31%) and 74 (36%) patients were detected using mp-MRI-bx and TRUS-bx, respectively. Overall, mp-MRI-bx detected fewer patients with low-grade (Gleason score [GS] 3 + 3) cancers (14/64 vs. 41/74) and more patients with intermediate/high-grade cancers (GS ≥3 + 4) (50/64 vs. 33/74) using fewer biopsy cores compared with TRUS-bx (p < 0.001). Using an "MRI-targeted-only" approach in men with PI-RADS ≥3 lesions reduced the number of men requiring repeated biopsies by 50%, decreased low-grade cancer diagnoses by 66%, and increased intermediate/high-grade cancer diagnoses by 52%. CONCLUSIONS: MRI-targeted biopsies have a high detection rate for significant PCa in patients with prior negative transrectal ultrasound-guided biopsies and preferentially detect intermediate/high-grade compared with low-grade tumors.

Apparent diffusion coefficient ratio correlates significantly with prostate cancer gleason score at final pathology.

PURPOSE: To evaluate the correlation between apparent diffusion coefficient measurements (ADCtumor and ADCratio ) and the Gleason score from radical prostatectomy specimens. MATERIALS AND METHODS: Seventy-one patients with clinically localized prostate cancer scheduled for radical prostatectomy were prospectively enrolled. Multiparametric magnetic resonance imaging (MRI) was performed prior to prostatectomy and mean ADC values from both cancerous (ADCtumor ) and benign (ADCbenign ) tissue were measured to calculate the ADCratio (ADCtumor divided by ADCbenign ). The ADC measurements were correlated with the Gleason score from the prostatectomy specimens. RESULTS: The association between ADC measurements and Gleason score showed a significant negative correlation (P < 0.001) with Spearman's rho for ADCtumor (-0.421) and ADCratio (-0.649). There was a statistically significant difference between ADC measurements and the Gleason score for all tumors (P = 0.001). Receiver operating characteristic curve analysis showed an overall area under the curve (AUC) of 0.73 (ADCtumor ) to 0.80 (ADCratio ) in discriminating Gleason score 6 from Gleason score ≥7 tumors. The AUC changed to 0.72 (ADCtumor ) and 0.90 (ADCratio ) when discriminating Gleason score ≤7(3+4) from Gleason score ≥7(4+3). CONCLUSION: ADC measurements showed a significant correlation with tumor Gleason score at final pathology. The ADCratio demonstrated the best correlation compared to the ADCtumor value and radically improved accuracy in discriminating Gleason score ≤7(3+4) from Gleason score ≥7(4+3) tumors.

Prostate cancer staging with extracapsular extension risk scoring using multiparametric MRI: a correlation with histopathology.

OBJECTIVES: To evaluate the diagnostic performance of preoperative multiparametric MRI with extracapsular extension (ECE) risk-scoring in the assessment of prostate cancer tumour stage (T-stage) and prediction of ECE at final pathology. MATERIALS AND METHODS: Eighty-seven patients with clinically localised prostate cancer scheduled for radical prostatectomy were prospectively enrolled. Multiparametric MRI was performed prior to prostatectomy, and evaluated according to the ESUR MR prostate guidelines by two different readers. An MRI clinical T-stage (cTMRI), an ECE risk score, and suspicion of ECE based on tumour characteristics and personal opinion were assigned. Histopathological prostatectomy results were standard reference. RESULTS: Histopathology and cTMRI showed a spearman rho correlation of 0.658 (p < 0.001) and a weighted kappa = 0.585 [CI 0.44;0.73](reader A). ECE was present in 31/87 (36 %) patients. ECE risk-scoring showed an AUC of 0.65-0.86 on ROC-curve for both readers, with sensitivity and specificity of 81 % and 78 % at best cutoff level (reader A), respectively. When tumour characteristics were influenced by personal opinion, the sensitivity and specificity for prediction of ECE changed to 61 %-74 % and 77 %-88 % for the readers, respectively. CONCLUSIONS: Multiparametric MRI with ECE risk-scoring is an accurate diagnostic technique in determining prostate cancer clinical tumour stage and ECE at final pathology. KEY POINTS: • Multiparametric MRI is an accurate diagnostic technique for preoperative prostate cancer staging • ECE risk scoring predicts extracapsular tumour extension at final pathology • ECE risk scoring shows an AUC of 0.86 on the ROC-curve • ECE risk scoring shows a moderate inter-reader agreement (K = 0.45) • Multiparametric MRI provides essential knowledge for optimal clinical management.

Office-based Magnetic Resonance Imaging-guided Transperineal Prostate Biopsy Without Antibiotic Prophylaxis: A Real-world Clinical Utility Study.

Background and objective: Advances in for magnetic resonance imaging (MRI)-guided transperineal biopsy (TPBx) techniques have facilitated outpatient prostate biopsies under local anaesthesia to lower postbiopsy infection rates. However, there is debate regarding antibiotic prophylaxis because of concerns regarding antibiotic resistance and interactions. Our objective was to assess the transition from office-based transrectal biopsy to TPBx performed under local anaesthesia without antibiotic prophylaxis despite potential risk factors for infectious complications. Methods: We conducted a prospective assessment of 665 men undergoing office-based MRI-guided TPBx. The primary outcome was the rate of urosepsis or febrile urinary tract infections requiring hospitalisation and/or antibiotics within 2 wk after biopsy. Secondary outcomes included patient-reported procedure tolerability and the prostate cancer detection rate. Key findings and limitations: TPBx using a median of nine cores per patient (range 4-15) detected prostate cancer in 534/665 men (80%). Only four men (0.6%) were hospitalised for suspected postbiopsy infection; no patient experienced urosepsis. The TPBx procedure was well tolerated, with low pain scores (median Visual Analogue Scale score of 2, interquartile range [IQR] 1-3) and positive patient ratings (median rating 1 [no problem], IQR 1-2). Limitations include the single-centre analysis and lack of randomisation for antibiotic prophylaxis. Conclusions and clinical implications: An office-based TPBx strategy under local anaesthesia without antibiotic prophylaxis is well tolerated and has a very low risk of side effects. This approach should be considered as the standard of care. Further studies may determine if a subgroup of predisposed men could benefit from antibiotic prophylaxis. Patient summary: For prostate biopsy the sampling needle can be inserted through the rectum or through the perineum, which is the skin between the rectum and the scrotum. Our study confirms that in everyday clinical practice, prostate biopsy via the perineum can be carried out under local anaesthetic and without routine use of antibiotics because of its lower risk of infection. Patients reported low pain scores and positive ratings for the overall experience.

Comparison of PSA density and lesion volume strategies for selecting men with equivocal PI-RADS 3 lesions on bpMRI for biopsies.

PURPOSE: To compare two strategies: Prostate-specific antigen density (PSAd) and lesion volume measurement in ruling out significant prostate cancer (sPCa) in men with equivocal Prostate Imaging Reporting and Data System (PI-RADS) category 3 index lesions on biparametric magnetic resonance imaging. METHODS: In total, 130 men from our database had index lesions with PI-RADS scores of 3. Prostate volume was measured using the ellipsoid method, in accordance with PI-RADS version 2.1 criteria. Index lesion volumes were also measured using the ellipsoidal formula on the diffusion-weighted imaging sequence with the highest b-value and sagittal T2 sequences. RESULTS: Among 130 men with PI-RADS category 3 index lesions, 23 (18%) had sPCa. In total, 6 of the 89 men with PSAd < 0.15 ng/mL2 (7%) had sPCa, whereas 8 of the 49 men with index lesion volumes < 0.5 mL (16%) had sPCa. The difference was statistically significant (McNemar, p < 0.0001). CONCLUSION: The PSAd strategy performed better than the lesion volume strategy in ruling out sPCa in men with equivocal PI-RADS category 3 index lesions.

Quantification of cross-vendor variation in ADC measurements in vendor-specific prostate MRI-protocols.

PURPOSE: The purpose of this study was to quantify the variability of Apparent Diffusion Coefficient (ADC) and test if there were statistically significant differences in ADC between MRI systems and sequences. METHOD: With a two-chamber cylindrical ADC phantom with fixed ADC values (1,000 and 1,600x10-6 mm2/s) a single-shot (ss) Echo Planar Imaging (EPI), a multi-shot EPI, a reduced field of view DWI (zoom) and a Turbo Spin Echo DWI sequence were tested in six MRI systems from three vendors at 1.5 T and 3 T. Technical parameters were according to Prostate Imaging Reporting and Data System Version 2.1. ADC maps were calculated by vendor specific algorithms. Absolute and relative differences in ADC from the phantom-ADC were calculated and differences between sequences were tested. RESULTS: At 3 T absolute differences from phantom given ADC (∼1,000 and âˆ¼ 1,600x10-6 mm2/s) were -83 - 42x10-6 mm2/s (-8.3%-4.2%) and -48 - 15x10-6 mm2/s (-3%-0.9%), respectively and at 1.5 T absolute differences were -81 - 26x10-6 mm2/s (-2.6%-8.1%) and -74 - 67x10-6 mm2/s (-4.6%-4.2%), respectively. Significant statistical differences in ADC measurements were identified between vendors in all sequences except for ssEPI and zoom at 3 T in the 1,600x10-6 mm2/s phantom chamber. Significant differences were also identified between ADC measurements at 1.5 T and 3 T in some of the sequences and vendors, but not all. CONCLUSION: The variation of ADC between different MRI systems and prostate specific DWI sequences is limited in this phantom study and without apparent clinical relevance. However, prospective multicenter studies of prostate cancer patients are needed for further investigation.

Danish Prostate Cancer Consortium Study 1 (DPCC-1) protocol: Multicentre prospective validation of the urine-based three-microRNA biomarker model uCaP.

INTRODUCTION: The primary objective of the Danish Prostate Cancer Consortium Study 1 (DPCC-1) is to provide validation for a novel urine-based microRNA biomarker, called uCaP, for a diagnosis of prostate cancer. METHODS AND ANALYSIS: Eligible participants are biopsy naïve men aged ≥18 years with prostate-specific antigen (PSA) levels ≥3 ng/mL, who are referred to prostate MRI due to suspicion of PC at one of the following three major urology/uroradiology centers: Aarhus University Hospital, Herlev & Gentofte University Hospital, or Odense University Hospital, where MRI and targeted biopsy are implemented in clinical use. Exclusion criteria include previous diagnosis of urogenital cancer, contraindication to MRI, gender reassignment treatment or PSA level >20 ng/mL. The participants will be asked to donate a urine sample in connection with their MRI. The study is observational, uses a diagnostic accuracy testing setup and will integrate into the current diagnostic pathway.We will measure the levels of the three microRNAs in the uCaP model (miR-222-3 p, miR-24-3 p and miR-30c-5p) in extracellular vesicle-enriched cell-free urine samples, to assess if uCaP can improve specificity and retain sensitivity for International Society of Urological Pathology Grade Group ≥2 PC, when used as a reflex test to PSA ≥3 ng/mL. We hypothesise that uCaP can improve selection for prostate MRI and reduce the number of unnecessary scans and biopsies. ETHICS AND DISSEMINATION: This study is approved by the Central Denmark Region Committee on Health Research Ethics (reference number: 1-10-72-85-22). All participants will provide written informed consent. Study results will be published in peer-reviewed journals and presented in scientific meetings. TRIAL REGISTRATION NUMBER: NCT05767307 at clinicaltrials.gov.

Early experience in avoiding biopsies for biopsy-naïve men with clinical suspicion of prostate cancer but non-suspicious biparametric magnetic resonance imaging results and prostate-specific antigen density < 0.15 ng/mL2: A 2-year follow-up study.

Background: Only limited data have been published on the diagnostic accuracy of combining biparametric (bp) magnetic resonance imaging (MRI) and prostate-specific antigen density (PSAd) to rule out biopsies. Purpose: The purpose is to assess the 2-year risk of being diagnosed with sPCa following the strategy of avoiding immediate biopsies in men with non-suspicious bp MRIs and a PSAd <0.15 ng/mL2. Material and Methods: Two hundred biopsy-naïve men with clinical suspicion of PCa underwent a pre-biopsy bp MRI from March to July 2019. Of these, 109 men had a Prostate Imaging Reporting and Data System (PI-RADS) score of 1-3 including 77 men with calculated PSAd <0.15 ng/mL2. As a result, no biopsies were performed in these 77 men, who were clinically followed up for at least 2 years and re-examined in case of rising suspicion of sPCa. The remaining 32 men with a calculated PSAd ≥0.15 ng/mL2 underwent systematic biopsies and targeted biopsies of any PI-RADS 3 lesion. Results: One of the 77 men (1.3%) had an sPCa diagnosed within 2 years of follow-up. All men were referred back to their general practitioner within 1 year and 9% (7/77) were re-referred to the urology department during follow-up. Among these men, 43% (3/7) continued to have PSA levels that were above their individual thresholds at confirmatory testing and underwent secondary MRI scans. Conclusions: No biopsies for men with bpMRI results exhibiting maximum PI-RADS 3 and with a PSAd <0.15 ng/mL2 resulted in a 2-year risk of being diagnosed with sPCa of 1.3%.

Outcome of 5-year follow-up in men with negative findings on initial biparametric MRI.

BACKGROUND: We assessed the 5-year risk of being diagnosed with significant prostate cancer following a low-suspicion biparametric magnetic resonance imaging result. METHODS: The study population was derived from a prospective database used to assess the diagnostic accuracy of biparametric magnetic resonance imaging for significant prostate cancer detection in 1020 biopsy-naïve men. Significant prostate cancer was defined as any core with Gleason grade group ≥3 or a maximum cancerous core length greater than 50% of Gleason grade group 2. A secondary definition of significant prostate cancer was also included: any core with prostate cancer Gleason grade group ≥2. Of the 1020 men, 305 had a low-suspicion biparametric magnetic resonance imaging result (Prostate Imaging Reporting and Data System score of 1 or 2) but four men were excluded from follow-up. Thus, the final study population consisted of 301 men, who were clinically followed-up from inclusion (November 2015 to June 2017) until 1 June 2021. FINDINGS: Overall, 1·7% (5/301) of the study population had significant prostate cancer diagnosed within 5 years (median 1480 days, Interquartile Range (1587-1382)) of their low-suspicion result and corresponding set of biopsies. When the secondary definition of significant prostate cancer was applied, this increased to 5% (15/301) of the study population. INTERPRETATION: The 5-year risk of being diagnosed with significant prostate cancer after a prebiopsy low-suspicion prebiopsy biparametric magnetic resonance imaging result was 1·7%.

For men enrolled in active surveillance, pre-biopsy biparametric magnetic resonance imaging significantly reduces the risk of reclassification and disease progression after 1 year.

AIMS: To assess the level of disease progression at confirmatory staging biopsies after 1 year of active surveillance (AS) and compare the detection rate of significant prostate cancers (PCas) in patients who underwent pre-biopsy biparametric magnetic resonance imaging (bpMRI) before the first set of diagnostic transrectal ultrasonography-guided biopsies (TRUS-bx) with the detection rate in patients who did not undergo pre-biopsy bpMRI. MATERIALS AND METHODS: Comparison of two patient groups enrolled in AS. Patients in Group A (n = 127) underwent pre-biopsy bpMRI followed by TRUS-bx ± targeted biopsies. Patients in Group B (n = 127) were enrolled in AS based on biopsy results from TRUS-bx only. RESULTS: Overall, 6% of the patients in Group A and 20% of the patients in Group B had an upgrade in Gleason grade from insignificant to significant PCa at confirmatory staging biopsies (odds ratio [OR], 3.5; p = .002; 95% confidence interval [CI], 1.6-7.9). CONCLUSIONS: Patients who underwent pre-biopsy bpMRI before the first set of diagnostic biopsies had a reduced risk of reclassification and disease progression after 1 year of AS. Thus, pre-biopsy bpMRI improves the selection of men who should be enrolled in AS.

International Multi-Site Initiative to Develop an MRI-Inclusive Nomogram for Side-Specific Prediction of Extraprostatic Extension of Prostate Cancer.

BACKGROUND: To develop an international, multi-site nomogram for side-specific prediction of extraprostatic extension (EPE) of prostate cancer based on clinical, biopsy, and magnetic resonance imaging- (MRI) derived data. METHODS: Ten institutions from the USA and Europe contributed clinical and side-specific biopsy and MRI variables of consecutive patients who underwent prostatectomy. A logistic regression model was used to develop a nomogram for predicting side-specific EPE on prostatectomy specimens. The performance of the statistical model was evaluated by bootstrap resampling and cross validation and compared with the performance of benchmark models that do not incorporate MRI findings. RESULTS: Data from 840 patients were analyzed; pathologic EPE was found in 320/840 (31.8%). The nomogram model included patient age, prostate-specific antigen density, side-specific biopsy data (i.e., Gleason grade group, percent positive cores, tumor extent), and side-specific MRI features (i.e., presence of a PI-RADSv2 4 or 5 lesion, level of suspicion for EPE, length of capsular contact). The area under the receiver operating characteristic curve of the new, MRI-inclusive model (0.828, 95% confidence limits: 0.805, 0.852) was significantly higher than that of any of the benchmark models (p < 0.001 for all). CONCLUSIONS: In an international, multi-site study, we developed an MRI-inclusive nomogram for the side-specific prediction of EPE of prostate cancer that demonstrated significantly greater accuracy than clinical benchmark models.

Magnetic resonance imaging-transrectal ultrasound image fusion guidance of prostate biopsies: current status, challenges and future perspectives.

The use of multiparametric magnetic resonance imaging (mpMRI) in prostate cancer (PCa) diagnosis is rapidly evolving to try to overcome the limitations of the current diagnostic pathway using systematic transrectal ultrasound-guided biopsies (TRUSbx) for all men with clinical suspicion of PCa. Prostate mpMRI allows for high quality lesion detection and characterization and has been shown to improve detection of significant PCa with a more accurate Gleason score grading. Suspicious lesions can be stratified by suspicion and sampled by selective MRI-guided targeted biopsies (TBx) for improved diagnostic accuracy. Several TBx methods have been established and include MRI/TRUS image fusion biopsies (cognitive or software-assisted) and in-bore biopsies, but none have yet proven superior in clinical practice. However, while MRI in-bore biopsy is not routinely used due to its costs and limited availability, MRI/TRUS image fusion is rapidly embraced as it allows skilled urologists to perform TBx in an outpatient clinic. Furthermore, it gives the operator the advantage of adding TBx to the systematic standard biopsy scheme, which is the currently recommended approach. With the anticipated increased future use of prebiopsy mpMRI, a more widespread implementation of MRI/TRUS image fusion platforms is concurrently expected in clinical practice. Therefore, the objective of this review is to assess the current status, challenges and future perspectives of prostate MRI/TRUS image fusion biopsies.

Comparison of bi- and multiparametric magnetic resonance imaging to select men for active surveillance.

BACKGROUND: Active surveillance of men with prostate cancer relies on accurate risk assessments because it aims to avoid or delay invasive therapies and reduce overtreatment. PURPOSE: To compare the diagnostic performance of pre-biopsy biparametric magnetic resonance imaging (MRI) with confirmatory multiparametric MRI in selecting men for active surveillance. MATERIAL AND METHODS: The study population included biopsy-naïve men with clinical suspicion of prostate cancer undergoing biparametric MRI followed by combined (standard plus MRI targeted) biopsies. Men diagnosed with prostate cancer who were subsequently enrolled in active surveillance and underwent a confirmatory multiparametric MRI within three months of diagnosis were included in the study. Discrepancies between the pre-biopsy biparametric MRI and the confirmatory multiparametric MRI were assessed. RESULTS: Overall, 101 men (median age = 64 years; median prostate-specific-antigen level = 6.3 ng/mL) were included. Nine patients were re-biopsied after multiparametric MRI for the following reasons: suspicion of targeting error (three patients); a new suspicious lesion detected by multiparametric MRI (five patients); and an increase in tumor volume (one patient) compared with biparametric MRI. Confirmatory biopsies showed a Gleason grade group (GG) upgrade of ≥2 in 4/6 patients with suspicion of more advanced disease (missed suspicious lesion, increase in tumor volume) on multiparametric MRI. However, although multiparametric MRI subsequently detected a GG ≥ 2 prostate cancer lesion missed by biparametric MRI in 4% (4/101) of included men, the difference did not reach statistical significance (McNemar, P = 0.133). CONCLUSION: Biparametric MRI could be used to select men eligible for active surveillance and a confirmatory multiparametric MRI performed shortly after inclusion seems unnecessary.

A predictive model based on biparametric magnetic resonance imaging and clinical parameters for improved risk assessment and selection of biopsy-naïve men for prostate biopsies.

BACKGROUND: Prostate cancer risk prediction models and multiparametric magnetic resonance imaging (mpMRI) are used for individualised pre-biopsy risk assessment. However, biparametric MRI (bpMRI) has emerged as a simpler, more rapid MRI approach (fewer scan sequences, no intravenous contrast-media) to reduce costs and facilitate a more widespread clinical implementation. It is unknown how bpMRI and risk models perform conjointly. Therefore, the objective was to develop a predictive model for significant prostate cancer (sPCa) in biopsy-naive men based on bpMRI findings and clinical parameters. METHODS: Eight hundred and seventy-six biopsy-naive men with clinical suspicion of prostate cancer (prostate-specific antigen, <50 ng/mL; tumour stage,

Prebiopsy Biparametric Magnetic Resonance Imaging Combined with Prostate-specific Antigen Density in Detecting and Ruling out Gleason 7-10 Prostate Cancer in Biopsy-naïve Men.

BACKGROUND: Multiparametric magnetic resonance imaging (MRI) combined with prostate-specific-antigen density (PSAd) enhances the detection of significant prostate cancer (sPCa). However, it is unclear whether simple biparametric (bp) MRI, which reduces scan sequences, time, and cost, may be an equally effective noninvasive tool for detecting and ruling out sPCa and avoiding biopsies in biopsy-naïve men. OBJECTIVE: To assess the diagnostic accuracy, predictive values, and best biopsy strategy combining bpMRI and PSAd in detecting and ruling out sPCa (Gleason score ≥7). DESIGN, SETTING, AND PARTICIPANTS: Assessment of 808 biopsy-naïve men with clinical suspicion of localised PCa (prostate-specific antigen <20ng/ml, rectal examination