Bicenter validation of a risk model for the preoperative prediction of extraprostatic extension of localized prostate cancer combining clinical and multiparametric MRI parameters.

BACKGROUND: This study aimed to validate a previously published risk model (RM) which combines clinical and multiparametric MRI (mpMRI) parameters to predict extraprostatic extension (EPE) of prostate cancer (PC) prior to radical prostatectomy (RP). MATERIALS AND METHODS: A previously published RM combining clinical with mpMRI parameters including European Society of Urogenital Radiology (ESUR) classification for EPE was retrospectively evaluated in a cohort of two urological university hospitals in Germany. Consecutive patients (n = 205, January 2015 -June 2021) with available preoperative MRI images, clinical information including PSA, prostate volume, ESUR classification for EPE, histopathological results of MRI-fusion biopsy and RP specimen were included. Validation was performed by receiver operating characteristic analysis and calibration plots. The RM's performance was compared to ESUR criteria. RESULTS: Histopathological T3 stage was detected in 43% of the patients (n = 89); 45% at Essen and 42% at Düsseldorf. Discrimination performance between pT2 and pT3 of the RM in the entire cohort was AUC = 0.86 (AUC = 0.88 at site 1 and AUC = 0.85 at site 2). Calibration was good over the entire probability range. The discrimination performance of ESUR classification alone was comparable (AUC = 0.87). CONCLUSIONS: The RM showed good discriminative performance to predict EPE for decision-making for RP as a patient-tailored risk stratification. However, when experienced MRI reading is available, standardized MRI reading with ESUR scoring is comparable regarding information outcome. A main limitation is the potentially limited transferability to other populations because of the high prevalence of EPE in our subgroups.

Adherence to a risk-adapted screening strategy for prostate cancer: First results of the PROBASE trial.

PROBASE is a population-based, randomized trial of 46 495 German men recruited at age 45 to compare effects of risk-adapted prostate cancer (PCa) screening starting either immediately at age 45, or at a deferred age of 50 years. Based on prostate-specific antigen (PSA) levels, men are classified into risk groups with different screening intervals: low-risk (<1.5 ng/ml, 5-yearly screening), intermediate-risk (1.5-2.99 ng/ml, 2 yearly), and high risk (>3 ng/ml, recommendation for immediate biopsy). Over the first 6 years of study participation, attendance rates to scheduled screening visits varied from 70.5% to 79.4%, depending on the study arm and risk group allocation, in addition 11.2% to 25.4% of men reported self-initiated PSA tests outside the PROBASE protocol. 38.5% of participants had a history of digital rectal examination or PSA testing prior to recruitment to PROBASE, frequently associated with family history of PCa. These men showed higher rates (33% to 57%, depending on subgroups) of self-initiated PSA testing in-between PROBASE screening rounds. In the high-risk groups (both arms), the biopsy acceptance rate was 64% overall, but was higher among men with screening PSA ≥4 ng/ml (>71%) and with PIRADS ≥3 findings upon multiparameter magnetic resonance imaging (mpMRI) (>72%), compared with men with PSA ≥3 to 4 ng/ml (57%) or PIRADS score ≤ 2 (59%). Overall, PROBASE shows good acceptance of a risk-adapted PCa screening strategy in Germany. Implementation of such a strategy should be accompanied by a well-structured communication, to explain not only the benefits but also the harms of PSA screening.

Unilateral Pelvic Lymph Node Dissection in Prostate Cancer Patients Diagnosed in the Era of Magnetic Resonance Imaging-targeted Biopsy: A Study That Challenges the Dogma.

PURPOSE: Bilateral extended pelvic lymph node dissection at the time of radical prostatectomy is the current standard of care if pelvic lymph node dissection is indicated; often, however, pelvic lymph node dissection is performed in pN0 disease. With the more accurate staging achieved with magnetic resonance imaging-targeted biopsies for prostate cancer diagnosis, the indication for bilateral extended pelvic lymph node dissection may be revised. We aimed to assess the feasibility of unilateral extended pelvic lymph node dissection in the era of modern prostate cancer imaging. MATERIALS AND METHODS: We analyzed a multi-institutional data set of men with cN0 disease diagnosed by magnetic resonance imaging-targeted biopsy who underwent prostatectomy and bilateral extended pelvic lymph node dissection. The outcome of the study was lymph node invasion contralateral to the prostatic lobe with worse disease features, ie, dominant lobe. Logistic regression to predict lymph node invasion contralateral to the dominant lobe was generated and internally validated. RESULTS: Overall, data from 2,253 patients were considered. Lymph node invasion was documented in 302 (13%) patients; 83 (4%) patients had lymph node invasion contralateral to the dominant prostatic lobe. A model including prostate-specific antigen, maximum diameter of the index lesion, seminal vesicle invasion on magnetic resonance imaging, International Society of Urological Pathology grade in the nondominant side, and percentage of positive cores in the nondominant side achieved an area under the curve of 84% after internal validation. With a cutoff of contralateral lymph node invasion of 1%, 602 (27%) contralateral pelvic lymph node dissections would be omitted with only 1 (1.2%) lymph node invasion missed. CONCLUSIONS: Pelvic lymph node dissection could be omitted contralateral to the prostate lobe with worse disease features in selected patients. We propose a model that can help avoid contralateral pelvic lymph node dissection in almost one-third of cases.

Risk and predictors of adverse pathology after radical prostatectomy in patients diagnosed with IUSP 1-2 prostate cancer at MRI-targeted biopsy: a multicenter analysis.

PURPOSE: Although active surveillance (AS) is recommended for low- to favorable intermediate-risk prostate cancer (PCa), risk of upgrading at radical prostatectomy (RP) is not negligible. Available studies based on systematic transrectal ultrasound biopsy might not be applicable to contemporary cohorts diagnosed with MRI-targeted biopsy (TB). The aim of the present study is to explore rates and risk factors for adverse outcomes (AO) at RP in patients with ISUP ≤ 2 PCa detected at TB with concomitant systematic biopsy (SB). METHODS: Multicenter, retrospective analysis of 475 consecutive patients with ISUP ≤ 2 PCa at MRI-TB + SB is treated with RP. AO were defined as ISUP upgrading, adverse pathology (upgrading to ISUP ≥ 3 and/or ≥ pT3 at RP, and/or pN1) (AP) or biochemical recurrence (BCR) in men with follow-up (n = 327). RESULTS: The rate of ISUP upgrading, upgrading ≥ 3, and AP were 39%, 21%, and 43%. Compared to ISUP2, men with ISUP1 PCa had a higher rate of overall upgrading (27 vs. 67%, p < 0.001), but less upgrading to ≥ 3 (27 vs. 10%, p < 0.001). AP was more common when ISUP2 was detected with a combined MRI-TB + SB approach compared to considering TB (p = 0.02) or SB (p = 0.01) alone. PSA, PSA density, PI-RADS, ISUP at TB, overall biopsy ISUP and EAU classification were predictors of upgrading to ISUP ≥ 3 and AP. The 1 year BCR-free survival was 94% with no differences in BCR rates between subgroups. CONCLUSION: Upgrading in ISUP ≤ 2 PCa remains prevalent even in men diagnosed in the MRI era. The use of MRI-TB with concomitant SB allows for the accurate identification of ISUP2 PCa and predicts the risk of AO at RP.

Retrograde Pyelography in the Presence of Urothelial Bladder Cancer Does Not Affect the Risk of Upper Tract Urothelial Cancer: A Retrospective Analysis of a Single-Centre Cohort.

OBJECTIVE: Patients with bladder cancer (BC) are at risk of developing upper tract urothelial carcinoma (UTUC). Therefore, CT urography is recommended for follow-up. To avoid intravenous contrast agents, retrograde pyelography (RPG) is an alternative. However, it is still unclear whether RPG increases the incidence of UTUC. The aim of this study was to investigate the impact of RPG in the presence of BC on the risk of developing UTUC. PATIENTS AND METHODS: Retrospectively analysing a total of 3,680 RPGs between 2009 and 2016, all patients with simultaneous BC (group 1) and those without synchronous BC (group 2) during RPG were compared. All patients were risk stratified according to the EORTC bladder calculator. In patients without BC during RPG, risk stratification was based on the worst prior tumour characteristics. RESULTS: A total of 145 patients with a history of BC were analysed. Of these, 112 patients underwent RPG with simultaneous BC. UTUC developed in 6 of 112 patients (5.4%) and 58.9% (66/112) had high-risk BC according to the EORTC bladder calculator. In the control group, one out of 33 (3%) patients with metachronous high-risk BC developed UTUC. CONCLUSIONS: Using RPG in the presence of BC did not increase the risk of UTUC. Due to the predominant number of high-risk/high-grade tumours, individual tumour biology appears to be the primary driver for the development of UTUC.

German S3 Evidence-Based Guidelines on Focal Therapy in Localized Prostate Cancer: The First Evidence-Based Guidelines on Focal Therapy.

BACKGROUND: Focal therapy (FT) is an option to treat localized prostate cancer (PCa) and preserve healthy prostate tissue in order to reduce known side effects from primary whole-gland treatment. The available FT modalities are manifold. Until now, national and international PCa guidelines have been cautious to propose recommendations regarding FT treatment since data from prospective controlled trials are lacking for most FT modalities. Moreover, none of the international guidelines provides a separate section on FT. In this purpose, we provide a synopsis of the consensus-based German S3 guidelines for a possible international use. SUMMARY: The recently published update of the German S3 guidelines, an evidence- and consensus-based guideline, provides a section on FT with recommendations for diagnostic work-up, indications, modalities, and follow-up. This section consists of 12 statements and recommendations for FT in the treatment of localized PCa. KEY MESSAGE: The German S3 guidelines on PCa are the first to incorporate recommendations for FT based on evidence and expert consensus including indication criteria for FT, pretreatment, and follow-up diagnostic pathways as well as an extended overview of FT techniques and the current supportive evidence.

High fibroblast-activation-protein expression in castration-resistant prostate cancer supports the use of FAPI-molecular theranostics.

PURPOSE: To evaluate fibroblast-activation-protein (FAP) expression in different clinical stages of prostate cancer (PC) with regards to utility of [68 Ga]Ga-FAPI-04 PET/CT imaging in patients with castration-resistant PC (CRPC). METHODS: Tissue microarrays (TMAs) were constructed from prostatic tissue from 94 patients at different stages of PC (primary PC, patients undergoing neoadjuvant androgen deprivation therapy, CRPC, and neuroendocrine PC (NEPC)) and were stained with anti-FAP monoclonal antibody. A positive pixel count algorithm (H-Index) was used to compare FAP expression between the groups. Additionally, three men with advanced CRPC or NEPC underwent [68 Ga]Ga-FAPI-04 PET/CT, and PET positivity was analyzed. RESULTS: The mean H-index for benign tissue, primary PC, neoadjuvant androgen deprivation therapy before radical prostatectomy, CRPC, and NEPC was 0.018, 0.031, 0.042, 0.076, and 0.051, respectively, indicating a significant rise in FAP expression with advancement of disease. Corroborating these findings [68 Ga]Ga-FAPI-04 PET/CT was highly positive in men with advanced CRPC. CONCLUSION: Increased FAP tissue expression supports the use of FAP inhibitor (FAPI)-molecular theranostics in CRPC.

Simulated clinical deployment of fully automatic deep learning for clinical prostate MRI assessment.

OBJECTIVES: To simulate clinical deployment, evaluate performance, and establish quality assurance of a deep learning algorithm (U-Net) for detection, localization, and segmentation of clinically significant prostate cancer (sPC), ISUP grade group ≥ 2, using bi-parametric MRI. METHODS: In 2017, 284 consecutive men in active surveillance, biopsy-naïve or pre-biopsied, received targeted and extended systematic MRI/transrectal US-fusion biopsy, after examination on a single MRI scanner (3 T). A prospective adjustment scheme was evaluated comparing the performance of the Prostate Imaging Reporting and Data System (PI-RADS) and U-Net using sensitivity, specificity, predictive values, and the Dice coefficient. RESULTS: In the 259 eligible men (median 64 [IQR 61-72] years), PI-RADS had a sensitivity of 98% [106/108]/84% [91/108] with a specificity of 17% [25/151]/58% [88/151], for thresholds at ≥ 3/≥ 4 respectively. U-Net using dynamic threshold adjustment had a sensitivity of 99% [107/108]/83% [90/108] (p > 0.99/> 0.99) with a specificity of 24% [36/151]/55% [83/151] (p > 0.99/> 0.99) for probability thresholds d3 and d4 emulating PI-RADS ≥ 3 and ≥ 4 decisions respectively, not statistically different from PI-RADS. Co-occurrence of a radiological PI-RADS ≥ 4 examination and U-Net ≥ d3 assessment significantly improved the positive predictive value from 59 to 63% (p = 0.03), on a per-patient basis. CONCLUSIONS: U-Net has similar performance to PI-RADS in simulated continued clinical use. Regular quality assurance should be implemented to ensure desired performance. KEY POINTS: • U-Net maintained similar diagnostic performance compared to radiological assessment of PI-RADS ≥ 4 when applied in a simulated clinical deployment. • Application of our proposed prospective dynamic calibration method successfully adjusted U-Net performance within acceptable limits of the PI-RADS reference over time, while not being limited to PI-RADS as a reference. • Simultaneous detection by U-Net and radiological assessment significantly improved the positive predictive value on a per-patient and per-lesion basis, while the negative predictive value remained unchanged.

Recovery of pad-free continence in elderly men does not differ from younger men undergoing robot-assisted radical prostatectomy for aggressive prostate cancer.

PURPOSE: To analyze urinary continence outcome following robot-assisted radical prostatectomy (RARP) for aggressive prostate cancer in men aged ≥ 70 and < 70 years. METHODS: Retrospective analyses of prospectively collected long-term data from a monocentric cohort of 350 men with D'Amico high-risk prostate cancer undergone robot-assisted radical prostatectomy at a single institution between 2005 and 2016. The association between time since operation and zero-pad urinary continence recovery was comparatively analyzed by separate pre-operative and post-operative Cox proportional-hazard regression models. RESULTS: Median age in the age group ≥ 70 years was 73 years compared with 62 years in the < 70 year age group. Distribution of men receiving adjuvant and salvage radiotherapy/hormonal therapy was similar in both age groups. Urinary continence recovery rate at 12, 24, and 36 months after surgery of men aged ≥ 70 years was 66, 79 and 83%, respectively, and statistically similar to that of men < 70 years: 71, 81, and 85% (log-rank test p = 0.24). Multivariable analyses demonstrated no significant difference in return to continence between the two age groups (p = 0.28 and p = 0.17). In addition, clinical stage and type of nerve sparing (unilateral, bilateral or non-nerve sparing) were found to be independently predictive of pad-free continence recovery. CONCLUSIONS: Regardless of age, return to continence in men with aggressive prostate cancer undergoing RARP continues to improve way beyond the first 12 months after surgery. Considering the dire effects of post-operative radiotherapy on continence in this aggressive cancer cohort, advanced age alone should not discourage recommending multimodal therapy involving RARP.

[What does the nonradiologist expect from the radiologist?] / Was erwartet der Nichtradiologe vom Radiologen?

BACKGROUND: Positron-emission tomography/computed tomography (PET/CT) and positron-emission tomography/magnetic resonance imaging (PET/MRI) are hybrid medical imaging techniques that are becoming increasingly important in the diagnostic workup of cancer. Correct definition and interpretation of results are key challenges for both radiologists/specialists in nuclear medicine as well as for the treating clinician. Strong interdisciplinary communication is prerequisite to solve the upcoming complexity of retrieved information generated by hybrid imaging. OBJECTIVES: Different indications for hybrid medical imaging and review of current theranostic principles from the perspective of clinicians/clinical oncologists. MATERIALS AND METHODS: The GBA guidelines and recommendations retrieved from the corresponding German S3 guidelines for the use of PET imaging are summarized, followed by a review of innovative clinical trials that promote PET-based therapeutic strategies and radioligand therapies. RESULTS: Next generation PET/CT and PET/MRI imaging are being increasingly used for diagnostic purposes and follow-up staging in malignant tumors. Radioligand therapy may have the potential to be a further cornerstone in personalized antitumor therapy. CONCLUSIONS: Careful implementation of hybrid medical imaging can clearly improve the quality of the diagnosis in cancer patients and even increase the quality of care for cancer patients. Close interdisciplinary collaboration is essential to optimize therapeutic strategies for each patient.

Classification of Cancer at Prostate MRI: Deep Learning versus Clinical PI-RADS Assessment.

Background Men suspected of having clinically significant prostate cancer (sPC) increasingly undergo prostate MRI. The potential of deep learning to provide diagnostic support for human interpretation requires further evaluation. Purpose To compare the performance of clinical assessment to a deep learning system optimized for segmentation trained with T2-weighted and diffusion MRI in the task of detection and segmentation of lesions suspicious for sPC. Materials and Methods In this retrospective study, T2-weighted and diffusion prostate MRI sequences from consecutive men examined with a single 3.0-T MRI system between 2015 and 2016 were manually segmented. Ground truth was provided by combined targeted and extended systematic MRI-transrectal US fusion biopsy, with sPC defined as International Society of Urological Pathology Gleason grade group greater than or equal to 2. By using split-sample validation, U-Net was internally validated on the training set (80% of the data) through cross validation and subsequently externally validated on the test set (20% of the data). U-Net-derived sPC probability maps were calibrated by matching sextant-based cross-validation performance to clinical performance of Prostate Imaging Reporting and Data System (PI-RADS). Performance of PI-RADS and U-Net were compared by using sensitivities, specificities, predictive values, and Dice coefficient. Results A total of 312 men (median age, 64 years; interquartile range [IQR], 58-71 years) were evaluated. The training set consisted of 250 men (median age, 64 years; IQR, 58-71 years) and the test set of 62 men (median age, 64 years; IQR, 60-69 years). In the test set, PI-RADS cutoffs greater than or equal to 3 versus cutoffs greater than or equal to 4 on a per-patient basis had sensitivity of 96% (25 of 26) versus 88% (23 of 26) at specificity of 22% (eight of 36) versus 50% (18 of 36). U-Net at probability thresholds of greater than or equal to 0.22 versus greater than or equal to 0.33 had sensitivity of 96% (25 of 26) versus 92% (24 of 26) (both P > .99) with specificity of 31% (11 of 36) versus 47% (17 of 36) (both P > .99), not statistically different from PI-RADS. Dice coefficients were 0.89 for prostate and 0.35 for MRI lesion segmentation. In the test set, coincidence of PI-RADS greater than or equal to 4 with U-Net lesions improved the positive predictive value from 48% (28 of 58) to 67% (24 of 36) for U-Net probability thresholds greater than or equal to 0.33 (P = .01), while the negative predictive value remained unchanged (83% [25 of 30] vs 83% [43 of 52]; P > .99). Conclusion U-Net trained with T2-weighted and diffusion MRI achieves similar performance to clinical Prostate Imaging Reporting and Data System assessment. © RSNA, 2019 Online supplemental material is available for this article. See also the editorial by Padhani and Turkbey in this issue.

Histopathological to multiparametric MRI spatial mapping of extended systematic sextant and MR/TRUS-fusion-targeted biopsy of the prostate.

PURPOSE: MRI has limited ability to detect multifocal disease or the full extent of prostate involvement with clinically significant prostate cancer (sPC). We compare the spatial co-localization at sextant resolution of MRI lesions and histopathological mapping by combined targeted and extended systematic biopsies. MATERIALS AND METHODS: Sextants were mapped for sPC (ISUP group ≥ 2) by 24-core transperineal systematic biopsies in 316 patients with suspicion for sPC and by MR lesions of PI-RADS score of ≥ 3. The gold standard is combined systematic (median 23 cores) and targeted biopsies. RESULTS: Of 316 men, 121 (38%) harbored sPC. Of these 121 patients, 4 (3%) had a negative MRI. MRI correctly identified 117/121 (97%) patients with sPC. In these patients, mpMRI missed no additional sPC in 96 (82%), while MRI-negative sPC lesions were present in 21 patients (18%). Of 1896 sextants, 379 (20%) harbored sPC. MR-positive sextants contained sPC in 26% (337/1275), compared to 7% (42/621) in MR-negative sextants. On a patient basis, sensitivity was 0.97, specificity 0.22, positive predictive value 0.43, and negative predictive value 0.91. On a sextant basis, sensitivity was 0.73, specificity 0.38, positive predictive value 0.26, and negative predictive value 0.93. CONCLUSION: MpMRI mapping agreed well with histopathology with, at the observed sPC prevalence and on a patient basis, excellent sensitivity and negative predictive value, and acceptable specificity and positive predictive value for sPC. However, 18% of sPC was outside the mpMRI mapped region, quantifying limitations of MRI for complete localization of disease extent. KEY POINTS: • Currently, exclusive MRI mapping of the prostate for focal treatment planning cannot be recommended, as significant prostate cancer may remain untreated in a substantial number of cases. • At the observed sPC prevalence and on a patient basis, mpMRI has excellent sensitivity and NPV, and acceptable specificity and PPV for detection of prostate cancer, supporting its use to detect suspicious lesions before biopsy. • Despite the excellent global performance, 18% of sPC was outside the mpMRI mapped region even when a security margin of 10 mm was considered, indicating that prostate MRI has limited ability to completely map all cancer foci within the prostate.

Retzius-sparing robot-assisted laparoscopic radical prostatectomy: functional and early oncologic results in aggressive and locally advanced prostate cancer.

BACKGROUND: Retzius-sparing robot-assisted laparoscopic radical prostatectomy (rsRARP) allows entire prostatectomy procedure via the pouch of Douglas. In low- and intermediate-risk prostate cancer (PCa) there is level 1 evidence that the Retzius-sparing approach impacts early continence recovery. Since specific data on aggressive and locally advanced cancer is lacking and avoiding rsRARP is presently suggested, we investigated urinary and sexual recovery, perioperative complications and early oncologic outcomes after rsRARP in this particular cohort. METHODS: Prospectively collected data of 50 consecutive men (median age 66 years) with high-risk PCa who underwent rsRARP in a single institution was analysed retrospectively. The follow-up for all patients was 12 months after surgery. RESULTS: 3 vs. 12 months after surgery, 82% vs. 98% of men used no pad or one safety pad and 50% vs. 72% used no pad. 89% of patients did not observe a decline of continence if postoperative radiotherapy was carried out. Considering the 17 preoperatively potent patients who underwent bi- or unilateral nerve-sparing surgery, 41% reported their first sexual intercourse within 1 year after rsRARP. 84% of patients had ≥pT3a disease and 42% positive surgical margins. A lymphadenectomy was done in 94% of patients with a median lymph node removal of 15 and lymph node metastasis in 13%. 34% underwent adjuvant radiotherapy and 22% adjuvant androgen deprivation therapy (ADT). 1-year recurrence-free survival was 96%, including 25% of patients on adjuvant or salvage ADT. CONCLUSIONS: RsRARP in high-risk PCa is feasible and results in excellent continence rates, even after postoperative radiotherapy. The potency rates are promising but need further clarification in larger cohorts. Reliable oncologic outcomes require longterm follow-up and are awaited.

Radiomic Machine Learning for Characterization of Prostate Lesions with MRI: Comparison to ADC Values.

Purpose To compare biparametric contrast-free radiomic machine learning (RML), mean apparent diffusion coefficient (ADC), and radiologist assessment for characterization of prostate lesions detected during prospective MRI interpretation. Materials and Methods This single-institution study included 316 men (mean age ± standard deviation, 64.0 years ± 7.8) with an indication for MRI-transrectal US fusion biopsy between May 2015 and September 2016 (training cohort, 183 patients; test cohort, 133 patients). Lesions identified by prospective clinical readings were manually segmented for mean ADC and radiomics analysis. Global and zone-specific random forest RML and mean ADC models for classification of clinically significant prostate cancer (Gleason grade group ≥ 2) were developed on the training set and the fixed models tested on an independent test set. Clinical readings, mean ADC, and radiomics were compared by using the McNemar test and receiver operating characteristic (ROC) analysis. Results In the test set, radiologist interpretation had a per-lesion sensitivity of 88% (53 of 60) and specificity of 50% (79 of 159). Quantitative measurement of the mean ADC (cut-off 732 mm2/sec) significantly reduced false-positive (FP) lesions from 80 to 60 (specificity 62% [99 of 159]) and false-negative (FN) lesions from seven to six (sensitivity 90% [54 of 60]) (P = .048). Radiologist interpretation had a per-patient sensitivity of 89% (40 of 45) and specificity of 43% (38 of 88). Quantitative measurement of the mean ADC reduced the number of patients with FP lesions from 50 to 43 (specificity 51% [45 of 88]) and the number of patients with FN lesions from five to three (sensitivity 93% [42 of 45]) (P = .496). Comparison of the area under the ROC curve (AUC) for the mean ADC (AUCglobal = 0.84; AUCzone-specific ≤ 0.87) vs the RML (AUCglobal = 0.88, P = .176; AUCzone-specific ≤ 0.89, P ≥ .493) showed no significantly different performance. Conclusion Quantitative measurement of the mean apparent diffusion coefficient (ADC) improved differentiation of benign versus malignant prostate lesions, compared with clinical assessment. Radiomic machine learning had comparable but not better performance than mean ADC assessment. © RSNA, 2018 Online supplemental material is available for this article.

Prospective comparison of transperineal magnetic resonance imaging/ultrasonography fusion biopsy and transrectal systematic biopsy in biopsy-naïve patients.

OBJECTIVES: To evaluate the value of multiparametric magnetic resonance imaging (mpMRI) in the detection of significant prostate cancer (PCa) and to compare transperineal MRI/ultrasonography fusion biopsy (fusPbx) with conventional transrectal systematic biopsy (sysPbx) in biopsy-naïve patients. PATIENTS AND METHODS: This multicentre, prospective trial investigated biopsy-naïve patients with suspicion of PCa undergoing transperineal fusPbx in combination with transrectal sysPbx (comPbx). The primary outcome was the detection of significant PCa, defined as Gleason pattern 4 or 5. We analysed the results after a study period of 2 years. RESULTS: The study included 214 patients. The median (range) number of targeted and systematic cores was 6 (2-15) and 12 (6-18), respectively. The overall PCa detection rate of comPbx was 52%. FusPbx detected more PCa than sysPbx (47% vs 43%; P = 0.15). The detection rate of significant PCa was 38% for fusPbx and 35% for sysPbx (P = 0.296). The rate of missed significant PCa was 14% in fusPbx and 21% in sysPbx. ComPbx detected significantly more significant PCa than fusPbx and sysPbx alone (44% vs 38% vs 35%; P < 0.005). In patients presenting with Prostate Imaging Reporting and Data System (PI-RADS) 4 and 5 lesions there was a higher detection rate of significant PCa than in patients presenting with PI-RADS ≤3 lesions in comPbx (61% vs 14%; P < 0.005). CONCLUSIONS: For biopsy-naïve men with tumour-suspicious lesions in mpMRI, the combined approach outperformed both fusPbx and sysPbx in the detection of overall PCa and significant PCa. Thus, biopsy-naïve patients may benefit from sysPbx in combination with mpMRI targeted fusPbx.

Multiparametric MRI and MRI/TRUS Fusion Guided Biopsy for the Diagnosis of Prostate Cancer.

Purpose of this chapter To demonstrate the timing, benefits, limitations and current controversies of multiparametric magnet resonance imaging (mpMRI) combined with fusion guided biopsy and consider how additional incorporation of multivariable risk stratification might further improve prostate cancer (PC) diagnosis. Recent findings MpMRI has been shown to add important information to the diagnostic pathway for prostate cancer. Fusion biopsy has also shown advantages in comparison to standard practice for biopsy-naïve men and men with previous biopsy in large prospective studies providing level 1b evidence. Adding upfront multivariable risk stratification followed by or combined with mpMRI diagnostic accuracy can further be improved. Regarding active surveillance (AS), mpMRI in combination with fusion biopsy can support initial candidate selection and may help to monitor disease progression. However, mpMRI and fusion biopsy are not without failure and conflicting data exists to what extend (systematic) biopsies can be omitted. Summary The integration of mpMRI into the diagnostic pathway for PC can add important information for further decision making, yet more prospective and randomized data is needed to establish reliable procedure standards after mpMRI acquisition.

Effective downsizing but enhanced intratumoral heterogeneity following neoadjuvant sorafenib in patients with non-metastatic renal cell carcinoma.

OBJECTIVES: To evaluate the safety and feasibility of sorafenib prior to surgery for downsizing tumors in patients with non-metastatic cT1-3 renal tumors together with a characterization of functional intratumoral heterogeneity (ITH). MATERIALS AND METHODS: The effects of 4-week sorafenib prior to curative surgery were assessed in a prospective, single-center, randomized, placebo-controlled, double-blinded, pilot trial in patients with T1-3N0M0 renal cell carcinoma (RCC). Patients received sorafenib or placebo for 28 days prior to surgery. MRI was performed at baseline and prior to surgery to calculate tumor volume. The clinical responses were further characterized on the molecular level by immunohistochemical stainings for Ki-67, cleaved caspase-3, and CD31. RESULTS: After enrolling 20 patients into the study, 14 patients were randomized, of which 12 patients were available for analysis. While no significant change in tumor volume was seen for placebo (range = -24.2-0.2%) a reduction of 29.0% (range = -4.9-61.1%) was detected for sorafenib (p < 0.05). Primary renal tumor diameter changed from 10.6 cm (range = 6.5-10.8) to 10.7 cm (range = 6.7-11.1) in the placebo group, and from 5.4 cm (range = 4.3-7.3) to 4.4 cm (range = 3.5-6.8) for the sorafenib group, at baseline vs. 28 days of treatment. Correlative assessment of proliferation, apoptosis, and microvessel density revealed an enhanced degree of functional ITH in treated patients suggesting adaptive and/or regenerative processes with potential relevance for the development of drug resistance. CONCLUSIONS: Sorafenib in standard dosage, given preoperatively for 28 days, was clinically active in downsizing tumors in patients with locally confined, non-metastatic RCC together but led to an enhanced functional ITH in the residual tumor tissue.

Diagnostic Accuracy of Transperineal MRI Fusion Biopsy in Comparison to Transrectal Biopsy with Regard to Incidental Histopathological Findings in Transurethral Resection of the Prostate.

OBJECTIVE: To investigate the diagnostic accuracy of transperineal MRI/transrectal ultrasound (TRUS) fusion prostate biopsy vs. transrectal prostate biopsy in transurethral resection (TUR) specimen of men undergoing TUR of the prostate (TURP) for symptomatic bladder outlet obstruction. MATERIAL AND METHODS: From a database of 3,509 men receiving prostate biopsy, all those undergoing TURP and negative prostate biopsy (n = 95; 45 transrectal, 50 transperineal fusion) were analysed. TURP specimens were compared with regard to incidental prostate cancer. RESULTS: Pre- and peri-interventional parameters in transrectal vs. fusion biopsy groups for age (65.2 ± 7.8 vs. 65.5 ± 7.3 years; p = 0.84), prostate specific antigen (10.7 ± 8.5 vs. 10.9 ± 8.7 ng/mL; p = 0.93), preoperative prostate volume (72.5 ± 26.1 vs. 71.8 ± 28.1 mL; p = 0.91) and resected weight (43.7 ± 21.9 vs. 41.4 ± 20.7 g; p = 0.61) showed no significant differences. Analysing the TURP specimen, 5 incidental T1a prostate cancers were found (3 Gleason 3 + 3 = 6; 2 Gleason 3 + 4 = 7, all in the transrectal biopsy group). Although, more biopsy cores were obtained in the MRI/TRUS fusion biopsy group (26 cores [interquartile range, IQR 24-28] vs. 14 cores [IQR 12-24], p < 0.01), there was no statistical impact of the obtained number of cores (p = 0.9) on diagnostic accuracy. Statistical analyses revealed significantly better diagnostic accuracy favoring image-guided fusion biopsy (p = 0.02). CONCLUSIONS: Our findings showed that a combination of MRI-targeted and systematic transperineal prostate biopsy improves patient safety. This is associated with a combination of transperineal biopsy technique and pre-interventional MRI.