MRI in-bore biopsy following MRI/US fusion-guided biopsy in patients with persistent suspicion of clinically significant prostate cancer.

PURPOSE: Patients with suspicion of clinically significant prostate cancer (csPC) on multiparametric prostate MRI (mpMRI) but negative or inconclusive MRI/US fusion-guided biopsy (FB) can be challenging in clinical practice. To assess the utility of MRI in-bore biopsy (IB) in patients with discordant imaging and histopathological findings after FB. METHODS: Consecutive patients with Prostate Imaging Reporting and Data System (PI-RADS) category 4 or 5 on mpMRI at 3T after FB without histologically confirmed csPC who underwent IB between 01/2014 and 05/2022, were retrospectively included. The primary objective was to assess the detection rate of csPC. Secondary objectives were to analyze clinical parameters, MRI parameters, and lesion localization. RESULTS: In the final cohort of 51 patients, the IB resulted in an overall detection rate of 71% for PC and 47% for csPC. Furthermore, in 55% of cases with initial low-grade PC, the Gleason score was upgraded after IB. CsPC was often detected apical and/or anterior. The detection rate for PC was 58% in PI-RADS category 4 and 94% in PI-RADS category 5 (csPC 39% and 61%, respectively). Patients with csPC had statistically significant smaller prostate volumes, a higher PI-RADS category, a higher prostate-specific antigen density (PSAD), and were older. CONCLUSIONS: For a relevant proportion of patients with PI-RADS category 4 or 5 and negative or inconclusive findings on previous FB, but with persistent suspicion of csPC, a subsequent IB verified the presence of csPC. Therefore, IB can be a backup in cases of uncertainty.

Improved diffusion-weighted imaging of the prostate: Comparison of readout-segmented and zoomed single-shot imaging.

OBJECTIVES: Diffusion weighted imaging (DWI) is the most important sequence for detection and grading prostate cancer (PCa), but it is considerably prone to artifacts. New approaches like zoomed single-shot imaging (z-EPI) with advanced image processing or multi-shot readout segmentation (rs-EPI) try to improve DWI quality. This study evaluates objective and subjective image quality (IQ) of rs-EPI and z-EPI with and without advanced processing. MATERIALS AND METHODS: Fifty-six consecutive patients (67 ± 8 years; median PSA 8.3 ng/ml) with mp-MRI performed at 3 Tesla between February and October 2019 and subsequently verified PCa by targeted plus systematic MRI/US-fusion biopsy were included in this retrospective single center cohort study. Rs-EPI and z-EPI were prospectively acquired in every patient. Signal intensities (SI) of PCa and benign tissue in ADC, b1000, and calculated high b-value images were analyzed. Endpoints were signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR), PCa contrast intensity (CI), and subjective IQ on a 5-point scale evaluated by three blinded readers. Wilcoxon signed rank test, Friedman test and Cohen's kappa coefficient was calculated. RESULTS: SNR, CNR, and PCa CI of z-EPI with and without advanced processing was superior to rs-EPI (p < 0.01), whereas no significant differences were observed between z-EPI with and without advanced processing. Subjective IQ was significantly higher for z-EPI with advanced processing compared rs-EPI for ADC, b1000, and calculated high b-values (p < 0.01). Compared to z-EPI without advanced processing, z-EPI with advanced processing was superior for ADC and calculated high b-values (p < 0.01), but no significant differences were shown for b1000 images. CONCLUSIONS: Z-EPI with and without advanced processing was superior to rs-EPI regarding objective imaging parameters and z-EPI with advanced processing was superior to rs-EPI regarding subjective imaging parameters for the detection of PCa.

Data on the detection of clinically significant prostate cancer by magnetic resonance imaging (MRI)-guided targeted and systematic biopsy.

This is a data article from the original publication "Reasons for missing clinically significant prostate cancer by targeted magnetic resonance imaging/ultrasound fusion-guided biopsy" [1]. From January 2014 to April 2019 a sample collective of 785 patients with 3T multiparametric magnetic resonance imaging (mp-MRI) of the prostate and subsequent combined systematic biopsy (SB) and magnetic resonance imaging/ultrasound (US) fusion-guided biopsy (TB) was retrospectively analyzed. Prostate cancer (PCa) detection by TB and/or additional SB was analyzed.

Impact of dynamic contrast-enhanced MRI in 1.5 T versus 3 T MRI for clinically significant prostate cancer detection.

PURPOSE: This study analyzes the value of dynamic contrast-enhanced MRI (DCE) of the prostate on 1.5 T and 3 T examinations in patients within PI-RADS category 4. METHODS: In this retrospective, bi-centric, cohort study all consecutive patients classified as PI-RADS 4 in mpMRI with 100 verified prostate cancers (PCa) in subsequent MRI/US-guided fusion biopsy were included for 1.5 T and 3 T, each. PCa detection in index lesions (IL) upgraded to PI-RADS 4 based on positive DCE findings was compared between 1.5 T and 3 T. Secondary objectives are subgroup analysis of PZ lesions and comparison of ISUP grade group distribution between 1.5 T and 3 T. RESULTS: In total, 293 patients within PI-RADS category 4, including 152 (mean 66 ± 8y; median PSA 6.4 ng/ml;116 PZ IL) in the 1.5 T group and 141 (mean 65 ± 8y; median PSA 7.2 ng/ml;100 PZ IL) in the 3 T group were included. Overall amount of PCa (66 % vs 71 %; p = 0.346) and portion of upgraded IL (28 % vs 21 %; p = 0.126) did not differ significantly. At 1.5 T PCa detection was higher in upgraded PZ lesions compared to 3 T (23 % vs 14 %; p = 0.048). The amount of upgraded PZ lesions with ISUP grade group 2-5 PCa was significantly higher at 1.5 T versus 3 T (13.8 % vs 4.0 %; p = 0.007). 33 % (11/33; 1.5 T) and 32 % (10/31; 3 T) of the ISUP grade group 1 PCa of the PZ lesions were detected in upgraded lesions (10% of all PZ index lesions, respectively). CONCLUSION: DCE enabled the detection of a substantial amount of additional clinically significant PCa in prostate mpMRI at 1.5 T. The effect was smaller at 3 T and was accompanied in relation to 1.5 T by higher risk of overdiagnosis due to detection of additional low-risk PCa.

Pre-operative magnetic resonance imaging can predict prostate cancer with risk for positive surgical margins.

PURPOSE: Analysis of patients with pre-operative 3 T multiparametric prostate MRI (mpMRI) to determine reliable MRI-based risk predictors of patients at risk for positive surgical margins (PSM) in robotic assisted radical prostatectomy (RPE). METHODS: Consecutive patients with 3 T mpMRI and subsequent RPE from 01/2015 to 12/2018 were retrospectively included. Patients were compared regarding clinical and MRI related parameters such as length of capsular tumor contact (LCC) and distance to the membranous urethra (UD). RESULTS: Forty-nine of 179 patients (27%) had PSM in 70 different localizations, with the majority located at the capsule (57%, 40/70), mostly apical and/or posterior. The second most often PSM occurred at the apical urethra (22%, 15/70). PCA was visible on mpMRI at the localization of PSM in 93% at the capsule and in 80% at the urethra. PSA, PI-RADS classification, extraprostatic extension (EPE), and seminal vesicles infiltration (SVI) on MRI were significantly higher / more frequent in patients with PSM. LCC (AUC 0.710), EPE (AUC 0.693), and UD (1-AUC 0.673) predicted PSM (overall). An UD of ≤ 3.5 mm showed the highest accuracy of 95% (J = 0.946) for PSM at the urethra and a LCC of ≥ 22.5 mm with 77% (J = 0.378) for PSM at the capsule. CONCLUSION: PSM occurred mostly in the apex and/or posteriorly at the capsule or at the apical urethra. LCC was the best MRI predictor for PSM at the capsule and UD for tumors with PSM at the apical urethra. Using these MRI parameters readers might pre-operatively determine PCA localizations at risk for PSM.

Single center analysis of an advisable control interval for follow-up of patients with PI-RADS category 3 in multiparametric MRI of the prostate.

To evaluate if follow-up mpMRI scans of patients in PI-RADS category 3 are safe enough to omit or delay prostate biopsy in the future and to determine an optimal control interval. This retrospective single center study includes consecutive PI-RADS category 3 patients with one or more follow-up mpMRI (T2WI, DWI, DCE) and subsequent MRI-targeted and systematic TRUS-guided biopsy between 2012 and 2018. Primary study objective was the verification of a significant PI-RADS category upgrade in follow-up mpMRI in patients with subsequent PCA positive biopsy versus patients with negative biopsy. Further objectives were development of the PI-RADS category and clinical parameters between initial and follow-up mpMRI in the context of histopathologic results and time interval. Eighty-nine patients (median PSA 6.6 ng/ml; PSAD 0.13 ng/ml/ml) were finally included (follow-up period 31 ± 18 months). 19 cases had PCA (median PSA 7.8 ng/ml; PSAD 0.14 ng/ml/ml). 4 cases had csPCA (median PSA 5.4 ng/ml; PSAD 0.13 ng/ml/ml) for which there was a significant PI-RADS upgrade after 12-24 months (mean 3.75; p = 0.01) compared to patients without PCA (mean 2.74). Without PCA the mean PI-RADS category decreased after 25-36 months (mean 2.74; p = 0.02). Clinical parameters did not change significantly except a PSAD increase for PCA patients after 24 months. Patients within PI-RADS category 3 may not need prompt biopsy since those with PCA reliably demonstrate a PI-RADS category upgrade in follow-up mpMRI after 12-24 months. PI-RADS 3 patients with negative biopsy do not benefit from follow-up mpMRI earlier than 24 months.

MRI grading for the prediction of prostate cancer aggressiveness.

OBJECTIVES: T o evaluate the value of multiparametric MRI (mpMRI) for the prediction of prostate cancer (PCA) aggressiveness. METHODS: In this single center cohort study, consecutive patients with histologically confirmed PCA were retrospectively enrolled. Four different ISUP grade groups (1, 2, 3, 4-5) were defined and fifty patients per group were included. Several clinical (age, PSA, PSAD, percentage of PCA infiltration) and mpMRI parameters (ADC value, signal increase on high b-value images, diameter, extraprostatic extension [EPE], cross-zonal growth) were evaluated and correlated within the four groups. Based on combined descriptors, MRI grading groups (mG1-mG3) were defined to predict PCA aggressiveness. RESULTS: In total, 200 patients (mean age 68 years, median PSA value 8.1 ng/ml) were analyzed. Between the four groups, statistically significant differences could be shown for age, PSA, PSAD, and for MRI parameters cross-zonal growth, high b-value signal increase, EPE, and ADC (p < 0.01). All examined parameters revealed a significant correlation with the histopathologic biopsy ISUP grade groups (p < 0.01), except PCA diameter (p = 0.09). A mixed linear model demonstrated the strongest prediction of the respective ISUP grade group for the MRI grading system (p < 0.01) compared to single parameters. CONCLUSIONS: MpMRI yields relevant pre-biopsy information about PCA aggressiveness. A combination of quantitative and qualitative parameters (MRI grading groups) provided the best prediction of the biopsy ISUP grade group and may improve clinical pathway and treatment planning, adding useful information beyond PI-RADS assessment category. Due to the high prevalence of higher grade PCA in patients within mG3, an early re-biopsy seems indicated in cases of negative or post-biopsy low-grade PCA. KEY POINTS: • MpMRI yields relevant pre-biopsy information about prostate cancer aggressiveness. • MRI grading in addition to PI-RADS classification seems to be helpful for a size independent early prediction of clinically significant PCA. • MRI grading groups may help urologists in clinical pathway and treatment planning, especially when to consider an early re-biopsy.

Comparison of 3 T mpMRI and pelvic CT examinations for detection of lymph node metastases in patients with prostate cancer.

PURPOSE: This study investigates preoperative lymph node metastases (LNM) detection accuracy by MRI and CT in patients with prostate cancer (PCA). METHODS: All patients with preoperative MRI, CT or both and subsequent radical prostatectomy (RPE) and lymphadenectomy (LA) were included in this retrospective cohort study. Prostate specific antigen (PSA), PI-RADS, ISUP grade group, clinical and pathological tumor (T) stage was compared between negative and positive nodal (N) stage. LNM were assessed with size and localization and weather they were preoperatively detected or not. In patients with preoperative CT and MRI, the results were compared intermodally. The reference standard was the histopathological results after RPE and LA. RESULTS: A total of 228 patients were analysed including 24 patients with confirmed LNM (N1; 11%). PSA (median 9.7 vs. 14 ng/ml), PI-RADS (median 4 vs. 5), ISUP (median 2 vs. 4), and cT/pT-stage (median T2 vs. T3) was significantly higher in patients with LNM. No LNM were found in patients with ISUP-1-PCA. MRI was able to detect 67% of patients with LNM. Lymph node metastases presented on MRI predominantly small, round-shaped, located parailiacally with a minimum SAD of 4 mm (vs. CT SAD of 8 mm). In comparison, MRI was superior to CT in the detection of LNM (sensitivity 81% vs. 33%; specificity 99% vs. 97). CONCLUSION: LNM were very rare in patients with PSA < 10 ng/ml, PI-RADS ≤ 4, and ≤ cT2. MRI could detect LNM up to 4 mm with a moderate sensitivity and high specificity. Thus, MRI might optimise the preoperative diagnostic and therapy planning of patients with PCA, whereas CT was clearly limited for N-stage assessment.

Comparison and prediction of artefact severity due to total hip replacement in 1.5 T versus 3 T MRI of the prostate.

PURPOSE: To evaluate image quality and diagnostic value of multiparametric prostate MRI (mpMRI) in patients with total hip replacement (THR) at 1.5 and 3 Tesla. METHODS: In this retrospective multicenter cohort study patients with uni- or bilateral THR and 1.5 T or 3 T mpMRI were included. Seventy consecutive, standard-of-care examinations per field strength were evaluated regarding their diagnostic value. The overall diagnostic value and prostate imaging quality score (PI-QUAL) were assessed. Artifact severity in the localizer and mpMRI sequences (T2w, DWI, DCE) was scored on a 3-point scale. Correlation between diagnostic value and artifacts was analysed. Moreover, a subgroup analysis focussed on image quality at different 3 T scanner generations. RESULTS: 140 consecutive patients (mean age 72, median PSA value 8.3 ng/ml) were included. When comparing 1.5 T to 3 T examinations, no significant differences were observed regarding the artifact severity of DWI and the localizer and the overall diagnostic value of the images. There was a strong correlation between the diagnostic value, PI-QUAL score, and artifact severity in the localizer and DWI. T2w and DCE sequences showed overall low artifacts. Significant improvement in image quality for 3 T at the latest scanner generation was observed, especially for DWI (p < 0.03). CONCLUSIONS: MpMRI of patients with THR can be conducted at both field strengths without significant differences in artifacts. The localizer might be useful as an early forecasting feature for diagnostic value and particularly for contrast medium application decision. Patients with THR could benefit from technically advanced scanner generation and rs/ptx-EPI DWI sequences.

[Risk-adapted prostate cancer screening-update 2021]. / Risikoadaptierte Früherkennung des Prostatakarzinoms ­ Update 2021.

BACKGROUND: Prostate cancer (PCa) is the most common cancer and the second leading cause of cancer death in men in industrialized countries. There is no commonly accepted prostate cancer screening strategy. Based on the experience of various international screening studies, the German Prostate Cancer Early Detection Study Based on a Baseline PSA Value in Young Men (PROBASE) was established in 2014. OBJECTIVE: Based on the positive results of retrospective cohort analyses, the PROBASE study is designed to demonstrate that a screening strategy based on risk stratification by a baseline prostate-specific antigen (PSA) level at age 45 or 50 years may be an alternative to population-based screening. PROBASE is presented in the context of other risk-adapted screening studies. MATERIALS AND METHODS: There are basically several approaches to improve the population-based screening of PCa. Known risk factors for prostate cancer are age, a certain genetic predisposition (BRCA 1/2) and other germline mutations as well as individual somatic mutations. RESULTS: A total of 23,301 participants were randomized to study arm A. Baseline PSA testing in study arm A categorized 89.18% of participants into the low-risk group, 9.32% into the intermediate-risk group, and 1.48% into the high-risk group. Thus, the risk assignment exactly matched the previously reported distribution. DISCUSSION: Baseline PSA-dependent, risk-adapted PSA screening has the potential to reduce the high incidence of overdiagnosis and ultimately overtreatment of insignificant prostate cancers of population-based screening through extended testing intervals in the low-risk group. In parallel with PROBASE, several risk-adapted screening strategies are currently being tested worldwide; the evaluation of which is also awaited in several years.

Arterial spin labelling as a gadolinium-free alternative in the detection of prostate cancer.

PURPOSE: To determine the capability of Gadolinium-free arterial spin labelling (ASL) sequences as novel, contrast-free, non-invasive alternative perfusion imaging method to differentiate prostate cancer (PCA) from benign prostate tissue compared to conventional DCE MRI. METHODS: Thirty men with histologically confirmed PCA were included in this prospectively enrolled single center cohort study. All patients received multiparametric MRI (T2, DWI, DCE) at 3 T with additional ASL of the PCA lesion. Primary endpoint was differentiability of PCA versus benign prostate tissue by signal intensities (SI) and contrast ratios (CR) in ASL in comparison to DCE. For DCE also Signal-Enhancement-Ratio (SER) of native and early contrast enhancement SI was assessed. Secondary objectives were differences regarding PCA localisation in peripheral (PZ) or transition zone (TZ) and PCA detection. RESULTS: In both, ASL and DCE, average SI of PCA differed significantly from SI in benign tissue in the TZ and PZ (p < 0,01, respectively). ASL had significantly higher CR discerning PCA and benign tissue in PZ and TZ (PZ = 5.19; TZ = 6.45) compared to DCE SI (PZ = 1.61; TZ = 1.43) and DCE SER (PZ = 1.59; TZ = 1.43) (p < 0.01, respectively). In subjective evaluation, PCA could be detected in ASL in 28 patients, compared to 29 in DCE. CONCLUSION: ASL had significantly higher CR differentiating PCA from benign tissue in PZ and TZ compared to DCE. Visual detection of PCA does not differ significantly between the two sequences. As perfusion gadolinium-based contrast media is seen more critical in the last few years, ASL seems to be a promising alternative to DCE in PCA detection.

Reasons for missing clinically significant prostate cancer by targeted magnetic resonance imaging/ultrasound fusion-guided biopsy.

OBJECTIVES: This study evaluates cases with clinically significant prostate cancer (csPCa) missed by targeted biopsy (TB) and analyzes the diagnostic impact of an additional systematic biopsy (SB) in a large patient collective. METHODS: Consecutive patients with a 3 T multiparametric prostate MRI (mpMRI) and a subsequent MRI/US fusion-guided TB plus 12-core US-guided SB from 01/2014 to 04/2019 were included in this study. Primary study endpoint was the analysis of cases with a csPCa missed by TB and detected by SB. Secondary study objectives were the PCa detection and the correlation with clinical and MRI parameters. RESULTS: In total 785 patients met the inclusion criteria. 342 patients had a csPCa (median PSAD 0.29 ng/mL/cm3). In 42 patients (13 %), a csPCa was detected only by SB. In 36 of these cases, the localization of the positive SB cores matched with the cancer suspicious region described on mpMRI (mCSR). Cases with a csPCA missed by TB showed either an insufficient MRI segmentation (prostate boundary correlation) (31 %) and/or insufficient lesion registration (lesion transfer, tracking, and/or matching) (48 %), a missed small lesion (14 %), or a failed center of a large lesion (10 %). Median PSAD of patients with non-significant PCa detected by SB was 0.15 ng/mL/cm3. CONCLUSIONS: Main reasons for missing a csPCa by TB were insufficient prostate segmentation or imprecise lesion registration within MRI/US fusion-guided biopsy. Consequently, verification of MRI quality, exact mCSR assessment, and advanced biopsy experience may improve accuracy. Altogether, an additional SB adds limited clinical benefit in men with PSAD ≤ 0.15 ng/mL/cm3.

PSMA PET/CT vs. CT alone in newly diagnosed biochemical recurrence of prostate cancer after radical prostatectomy: Comparison of detection rates and therapeutic implications.

OBJECTIVES: To compare prostate specific membrane antigen (PSMA) Positron Emission Tomography/Computed Tomography (PET/CT) and computed tomography (CT) alone for the detection of biochemical recurrence of prostate cancer (PCa) and effect on treatment. METHODS: This retrospective study included 59 patients with recently recorded biochemical recurrence of PCa (mean PSA 1.96 ± 1.64 ng/mL) after radical prostatectomy. Patients received PET/CT with either 68Ga-PSMA-11 (n = 36) or 18F-PSMA-1007 (n = 23). PET/CT and CT images were evaluated separately in regard to PCa lesion count, type, and localisation by two physicians. Histopathology, follow-up imaging and PSA levels after salvage irradiation served as reference standard. A McNemar test was used to compare detection rates. Changes in therapeutic approaches based on staging differences between CT alone and PET/CT were assessed in a virtual multidisciplinary tumour board. RESULTS: There were 142 lesions in 50 of 59 patients. PSMA PET/CT detected 141 lesions (99.3 %) in 50 patients (84.7 %), while CT detected 72 lesions (50.7 %) in 29 patients (49.2 %). A significantly higher detection rate of PSMA PET/CT was observed on a lesion-based analysis (p < 0.0001) and on a patient based analysis (p < 0.0001). Herein, both 68Ga- and 18F-PSMA PET/CT performed significantly better than CT alone (p < 0.0001, respectively). In 9 patients (15.3 %) no relapse was detectable by either modality. All lesions detected by CT were also detected by PSMA PET/CT. In 38 patients PSMA PET/CT detected more lesions than CT alone, altering the treatment approach in 22 of these patients. CONCLUSION: PSMA PET/CT is superior to CT alone in detecting biochemical recurrence in PCa patients after radical prostatectomy and offered additional therapeutic options in a substantial number of patients.

Magnetic resonance imaging improves the prediction of tumor staging in localized prostate cancer.

OBJECTIVES: The aim of this study was to investigate 3 Tesla multiparametric magnetic resonance imaging (mpMRI)-based predictors for the pretherapeutic T staging of prostate cancer and their accuracy. METHODS: Consecutive patients with 3 Tesla mpMRI, positive systematic and MR-targeted biopsy, and subsequent radical prostatectomy (RPE) between 01/2016 and 12/2017 were included. MRI parameters such as measurable extraprostatic extension (EPE) (≥ 3 mm), length of (pseudo)capsular contact (LCC), invasion of neurovascular bundle (NVBI), and/or seminal vesicles lesion contact (SVC) or infiltration (SVI) were assessed and correlated to clinical and histopathological results. RESULTS: 136 men were included. In 76 cases, a pT2 stage was determined, in 29 cases a pT3a, and in 31 a pT3b stage. The positive and negative predictive values (PPV, NPV) for the detection of T3 by measurable EPE on MRI was 98% (CI 0.88-1) and 81% (CI 0.72-0.87). No visible NVBI was found in pT2 patients (NPV 100%; CI 0.95-1). ROC analysis for T3a prediction with LCC (AUC 0.81) showed a sensitivity of 87% and a specificity of 62% at a threshold of 12.5 mm (J = 0.485) and 93% and 58% at 11 mm (Jmax = 0.512). All patients with pT3a had a LCC > 5 mm. In case of pT3b, 29/31 patients showed a SVC (PPV 76%, CI 0.61-0.87; NPV 98%, CI 0.93-0.99), and 23/31 patients showed a SVI (PPV 100%, CI 0.86-1; NPV 93%, CI 0.87-0.96). EPE (p < 0.01), LCC (p = 0.05), and SVC (p = 0.01) were independent predictors of pT3. CONCLUSIONS: MRI-measurable EPE, LCC, and SVC were reliable, independent, preoperative predictors for a histopathological T3 stage. A LCC ≥ 11 mm indicated a pT3a stage, whereas a LCC < 5 mm excluded it. On MRI, visible SVI or even SVC of the PCa lesion was reliable preoperative predictors for a pT3b stage.

Advanced diffusion weighted imaging of the prostate: Comparison of readout-segmented multi-shot, parallel-transmit and single-shot echo-planar imaging.

PURPOSE: This study evaluates objective and subjective image quality (IQ) of three different diffusion weighted imaging (DWI) sequences in prostate MRI at 3.0 Tesla within the same patients. METHOD: Thirty-six consecutive patients (70 ± 8 years) with multi-parametric prostate MRI (mp-MRI; 3 T) and subsequently verified prostate cancer (PCa) by targeted plus systematic MR/US-fusion biopsy from 03/2016 to 12/2017 were included. Readout-segmented (rs) multi shot echo-planar imaging (EPI), parallel transmit (ptx) EPI, and single-shot (ss) EPI with b-values of 0, (500,) 1,000 s/mm² and calculated b1,500 were prospectively acquired of every patient. Signal intensities (SI) of PCa and benign tissue (peripheral and transition zone; PZ and TZ) in ADC, b1,000, and calculated b1,500 images were analyzed. Endpoints were signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR), and subjective IQ on a 5-point scale by two blinded readers. RESULTS: For ss-EPI ADC, b-values of 1,000, and calculated 1,500 s/mm² images showed a higher SNR compared to rs-EPI and ptx-EPI (p < 0.01). CNR of PCa and benign tissue was significantly higher for rs-EPI in high b value images compared to ptx-EPI and ss-EPI (p < 0.01). Subjective IQ was significantly higher for rs-EPI (p < 0.01). Significantly higher ADC reduction combined with signal increase on high b value images for PCa compared to the surrounding healthy tissue in PZ and TZ (PCa contrast intensity) was detected for rs-EPI (p < 0.01). Single PCa lesions could only be recognized and correlated on rs-EPI. CONCLUSIONS: Rs-EPI and ptx-EPI were superior to ss-EPI regarding contrast intensity of PCA, but inferior regarding SNR. Subjective imaging parameters were superior for rs-EPI. Especially rs-EPI, but also ptx-EPI might improve and faciliate prostate cancer detection, rs-EPI at the expense of a longer acquisition time.

Multiparametric magnetic resonance imaging can exclude prostate cancer progression in patients on active surveillance: a retrospective cohort study.

OBJECTIVES: To assess the ability of multiparametric MRI (mp-MRI) of the prostate to exclude prostate cancer (PCa) progression during monitoring patients on active surveillance (AS). METHODS: One hundred forty-seven consecutive patients on AS with mp-MRI (T2WI, DWI, DCE-MRI) at 3T were initially enrolled. Fifty-five received follow-up mp-MRI after a minimum interval of 12 months and subsequent targeted MR/US fusion-guided biopsy (FUS-GB) plus concurrent systematic transrectal ultrasound-guided (TRUS-GB) biopsy as reference standard. Primary endpoint was the negative predictive value (NPV) of the follow-up mp-MRI to exclude histopathologic tumor progression using PRECISE recommendations. Secondary endpoints were the positive predictive value (PPV), sensitivity, specificity, Gleason score (GS) upgrades, and comparison of biopsy method. RESULTS: Of 55 patients, 29 (53%) had a GS upgrade on re-biopsy. All 29 patients showed a tumor progression on follow-up mp-MRI. Fifteen of 55 patients (27%) displayed signs of tumor progression, but had stable GS on re-biopsy. None of the 11 patients (20%) without signs of progression on follow-up mp-MRI had a GS upgrade on re-biopsy. The NPV was 100%, PPV was 66%, sensitivity was 100%, and specificity 42%. FUS-GB resulted in GS upgrade significantly more often (n = 28; 51%) compared with TRUS-GB (n = 12; 22%; p < 0.001). CONCLUSIONS: (Follow-up) Mp-MRI can reliably exclude PCa progression in patients on AS. Standard serial re-biopsies might be waived if follow-up mp-MRIs are stable. Over 60% of patients with signs of tumor progression on mp-MRI during AS had a GS upgrade on re-biopsy. Targeted re-biopsies should be performed if cancer progression or higher-grade PCa is suspected on mp-MRI. KEY POINTS: • None of the patients with unsuspicious mp-MRI had a GS upgrade in re-biopsy and mp-MRI might replace serial biopsies in these cases • More than 60% of patients with mp-MRI signs of tumor progression had subsequent Gleason score (GS) upgrades • Targeted re-biopsies should be performed in case of higher GS cancer suspicion on mp-MRI.

Comparison of analgesic techniques in MRI-guided in-bore prostate biopsy.

OBJECTIVES: To evaluate different analgesic techniques in MRI-guided in-bore prostate biopsy (IB-GB) regarding the influence on patient procedural experience of pain. METHODS: Two hundred fifty-two consecutive patients who had received an IB-GB either with intrarectal instillation of 2% lidocaine gel (n = 126, group A) or with periprostatic nerve block (PPNB) with 2% mepivacaine (n = 126, group B) were retrospectively included in this study. Pain scores were measured on a visual analog scale, the operating room time (ORT) was recorded for each biopsy and correlations between the parameters were analysed. RESULTS: Pain scores for IB-GB were slightly lower in group B compared with group A (2.0 ± 1.9; 2.4 ± 1.7; p = 0.02). In group A, significantly more targeted biopsy cores were acquired (group B: 5.2 ± 1.1; group A: 5.6 ± 0.8; p < 0.01). ORT was comparable and not significantly different in both groups. There was only a weak correlation between pain scores and ORT in group B (rS = 0.22; p = 0.01), but no correlation between pain scores and the number of biopsy cores or the prostate volume. CONCLUSIONS: Pain levels are generally low for MRI-guided in-bore biopsy using either PPNB or intrarectal instillation of lidocaine gel. A statistically significant, slightly lower pain score was documented for PPNB and might be preferred when the focus is analgesia. On the other hand, due to the minor difference and easier administration, intrarectal gel instillation seems to be a reasonable practice for standard analgesia for MRI-guided in-bore biopsy. KEY POINTS: • Pain levels were low for MRI-guided in-bore biopsy using either PPNB or intrarectal instillation of lidocaine gel as analgesic method. • PPNB prior to IB-GB resulted in a slightly lower pain score but required a higher effort. • Intrarectal gel anaesthesia seems to be a reasonable practice for standard analgesia for IB-GB in an outpatient setting.

Analysis of PI-RADS 4 cases: Management recommendations for negatively biopsied patients.

PURPOSE: To evaluate if subgroups of patients assigned to MRI category PI-RADS 4 regarding clinical and MRI imaging aspects have distinct risks of prostate cancer (PCa) to facilitate adequate clinical management of this population, especially after negative targeted biopsy. METHODS: This prospective, IRB approved single center cross-sectional study includes 931 consecutive patients after mp-MRI at 3 T for PCa detection. 193 patients with PI-RADS assessment category 4 received subsequent combined targeted MRI/US fusion-guided and systematic 12-core TRUS-guided biopsy as reference standard and were finally analyzed. The primary endpoint was PCa detection of PI-RADS 4 with MRI subgroup analyses. Secondary endpoints were analyses of clinical data, location of PCa, and detection of targeted biopsy cores. RESULTS: PCa was detected in 119 of 193 patients (62%) including clinically significant PCa (csPCa; Gleason score ≥3 + 4 = 7) in 92 patients (48%). MRI subgroup analysis revealed 95% PCa (73% csPCa) in unambiguous PI-RADS 4 index lesions without additional, interfering signs of prostatitis in the peripheral zone or overlaying signs of severe stromal hyperplasia in the transition zone according to PI-RADS v2. Transition zone confined PI-RADS-4-lesions with overlaying signs of stromal hyperplasia showed PCa only in 11% (4% csPCa). Targeted biopsy cores missed the csPCa index lesion in 7% of the patients. PSA density (PSAD) was significantly higher in PCa patients. CONCLUSIONS: Small csPCa can reliably be detected with mp-MRI by experienced readers, but can be missed by targeted MR/US fusion biopsy alone. Targeted re-biopsy of unambiguous (peripheral) PI-RADS-4-lesions is recommended; whereas transition zone confined PI-RADS-4-lesions with overlaying signs of stromal hyperplasia might be followed-up by re-MRI primarily.

[PSA screening and molecular markers]. / PSA-Screening und molekulare Marker.

BACKGROUND: Prostate cancer (PCA) is the most common type of cancer in men. The significant increase in incidence is most likely caused by the overdiagnosis of prostate cancer by widespread prostate-specific antigen (PSA) screening. OBJECTIVES: This article reviews the three largest randomized trials of PSA-based prostate cancer screening and the benefits and disadvantages of general PSA screening. It gives an overview about the strategies to avoid the harms from overdetection and overtreatment without missing clinically relevant tumors. METHODS: This review article is based on a literature search in the PubMed database on PSA-based screening, molecular serum markers and risk-adapted PSA screening. RESULTS: In contrast to the CAP and PLCO trial, the ERSPC study reports a reduced relative and absolute mortality risk. Furthermore, the use of the PSA was associated with significantly lower risk of metastatic disease. In order to avoid unnecessary biopsy and overtreatment including treatment of insignificant prostate cancer, a number of tests have been proposed to improve the specificity of the PSA screening including the PHI, the 4Kscore and the risk-adapted PSA screening. The assessment of a baseline PSA level in the fifth decade allows subsequent risk-adapted PSA screening intervals. This concept is currently evaluated by the largest prospective multicenter trial, the PROBASE-trial. CONCLUSIONS: Neither a complete rejection of a PSA-based screening nor a general PSA testing is a final solution to this dilemma. A risk-adapted PSA screening according to a baseline PSA as well as serum markers may reduce unnecessary diagnostic and therapeutic interventions and its attendant morbidities without a decrease in sensitivity.

Influence of arterial input function (AIF) on quantitative prostate dynamic contrast-enhanced (DCE) MRI and zonal prostate anatomy.

PURPOSE: Reproducibility of quantitative perfusion analysis of DCE requires a standardized AIF acquisition. However, there are many different approaches for AIF assessment so that the absolute values of perfusion parameters may vary depending on the used method. This study analyzes the influence of the method of AIF determination on quantitative DCE-MRI. METHODS: In this retrospective, single-center, cohort study three different methods of AIF determination in 50 consecutive patients with multiparametric MRI of the prostate were conducted. As a reference, AIF was selected manually by defining a region of interest in an artery manually (AIFm). The second method (AIFa), based on an automated algorithm and the third, population-derived AIFp where then compared. Primary endpoint were differences in the performance of the perfusion parameters Ktrans, ve and kep regarding the AIF acquisition methods, secondary endpoints consisted of the evaluation of differences in the peripheral and transition zone of the prostate (PZ, TZ). RESULTS: In all three methods, Ktrans, ve, and kep were significantly higher in PZ than in TZ with Ktrans showing least overlapping. There were no significant differences for Ktrans determined with AIFm and AIFa (0.3 ±â€¯0.2 min-1 for PZ for both and 0.5 ±â€¯0.3 min-1 for TZ in AIFm and 0.4 ±â€¯0.3 min-1 in AIFa), while there were great differences between AIFa and AIFp and AIFm and AIFp (0.1 ±â€¯0.03 min-1 for TZ and PZ in AIFp). Spearman test demonstrated good correlation of values for Ktrans and kep in all 3 methods (ρ ≥ 0.76). AIFa showed a success rate of 98% in finding the artery. CONCLUSION: AIFa is a recommendable user-independent automatical method to determine quantitative perfusion parameters allowing an objective measurement and saving interactive time for the radiologist. AIFp may be applied as second alternative method.