Quaternary Zinc Alloys with Magnesium, Calcium and Strontium after Hydrostatic Extrusion-Microstructure and Its Impact on Mechanical and Corrosion Properties.

The development of bioabsorbable implants from Zn alloys is one of the main interests in the new generation of biomaterials. The main drawbacks of Zn-based materials are their insufficient mechanical properties. In the presented studies, a quaternary alloy composed of zinc with magnesium (0.2-1 wt. %), calcium (0.1-0.5 wt. %) and strontium (0.05-0.5 wt. %) was prepared by gravity casting followed by hot extrusion and then by hydrostatic extrusion. Microstructural characterization using scanning electron microscopy (SEM) and X-ray diffraction (XRD) phase analysis was performed. The mechanical properties were examined, using static tensile tests. Corrosion properties were analyzed using immersion tests. Samples were immersed in Hanks' solution (temperature = 37 °C, pH = 7.4) for 14 days. All alloys were subjected after corrosion to SEM observations on the surface and cross-section. The corrosion rate was also calculated. The microstructure of the investigated quaternary alloy consists of the α-Zn grains and intermetallic phases Mg2Zn11, CaZn13 and SrZn13 with different grain sizes and distribution, which impacted both mechanical and corrosion properties. Thanks to the alloying by the addition of Mg, Ca, and Sr and plastic deformation using hydrostatic extrusion, outstanding mechanical properties were obtained along with improvement in uniformity of corrosion rate.

Validation of the updated Bosniak classification (2019) in pathologically confirmed CT-categorised cysts.

INTRODUCTION: The updated Bosniak classification in 2019 (v2019) addresses vague imaging terms and revises the criteria with the intent to categorise a higher proportion of cysts in lower-risk groups and reduce benign cyst resections. The aim of the present study was to compare the diagnostic accuracy and inter-observer agreement rate of the original (v2005) and updated classifications (v2019). METHOD: Resected/biopsied cysts were categorised according to Bosniak classifications (v2005 and v2019) and the diagnostic accuracy was assessed with reference to histopathological analysis. The inter-observer agreement of v2005 and v2019 was determined. RESULTS: The malignancy rate of the cohort was 83.6% (51/61). Using v2019, a higher proportion of malignant cysts were categorised as Bosniak ≥ III (88.2% vs 84.3%) and a significantly higher percentage were categorised as Bosniak IV (68.9% vs 47.1%; p = 0.049) in comparison to v2005. v2019 would have resulted in less benign cyst resections (13.5% vs 15.7%). Calcified versus non-calcified cysts had lower rates of malignancy (57.1% vs 91.5%; RR,0.62; p = 0.002). The inter-observer agreement of v2005 was higher than that of v2019 (kappa, 0.70 vs kappa, 0.43). DISCUSSION: The updated classification improves the categorisation of malignant cysts and reduces benign cyst resection. The low inter-observer agreement remains a challenge to the updated classification system.

Multicenter Randomized Trial Assessing MRI and Image-guided Biopsy for Suspected Prostate Cancer: The MULTIPROS Study.

Background The optimal diagnostic pathway for prostate cancer (PCa) is evolving, requiring further evaluation in a randomized controlled trial. Purpose To assess the diagnostic accuracy of prebiopsy multiparametric MRI in the identification of clinically significant PCa (csPCa) using radical prostatectomy (RP) specimens as the reference standard, and to test the diagnostic accuracy of combined US and MRI fusion-targeted biopsy with systematic biopsies. Materials and Methods In a prospective randomized controlled trial including university hospitals, men with suspected PCa were recruited between January 2015 and August 2020 to assess the diagnostic accuracy of multiparametric MRI before biopsy in detection of csPCa at biopsy and RP histopathologic structure (primary outcome). Men with lesions suspicious for cancer (Prostate Imaging and Reporting Data System [PI-RADS] ≥3) at multiparametric MRI were first randomized to either systematic random prostate biopsies alone (control group) or US and MRI fusion-targeted biopsies with systematic random prostate biopsies (intervention group) at a one-to-one ratio to compare the diagnostic accuracy of systematic random versus combined fusion with systematic random biopsies (secondary outcome). A subset of recruited participants (n = 89) underwent RP and histologic sectioning. Results There were 582 participants who were eligible to undergo multiparametric MRI (mean age, 65 years ± 6 [SD]). In total, 413 had a PI-RADS score of at least 3 and were randomized into either the intervention group (207 of 413; 50.1%) or control group (206 of 413; 49.9%). The csPCa detection rate in the intervention group was higher, with an adjusted odds ratio of 1.79 (95% CI: 1.14, 2.79; P = .01). A subgroup of 89 men underwent RP (21.5%; 89 of 413). Multiparametric MRI helped correctly identify 131 of 182 csPCa foci in 89 men (sensitivity, 72%; 95% CI: 65, 78). The specificity, positive predictive value, and negative predictive value were 71% (91 of 128), 78% (131 of 168), and 64% (91 of 142), respectively. Conclusion Prebiopsy multiparametric MRI was accurate in the depiction of clinically significant PCa. Combining US and MRI fusion-targeted biopsies with systematic biopsies helped detect more clinically significant lesions than did systematic biopsies alone. Clinical trial registration no. NCT02745496 © RSNA, 2023 Supplemental material is available for this article.

Preoperative imaging accuracy in size determination of prostate cancer in men undergoing radical prostatectomy for clinically localised disease.

OBJECTIVES: To compare the accuracy of pre-surgical prostate size measurements using mpMRI and USWE with imaging-based 3D-printed patient-specific whole-mount moulds facilitated histopathology, and to assess whether size assessment varies between clinically significant and non-significant cancerous lesions including their locations in different zones of the prostate. METHODS: The study population included 202 men with clinically localised prostate cancer opting for radical surgery derived from two prospective studies. Protocol-based imaging data was used for measurement of size of prostate cancer in clinically localised disease using MRI (N = 106; USWE (N = 96). Forty-eight men overlapped between two studies and formed the validation cohort. The primary outcome of this study was to assess the accuracy of pre-surgical prostate cancerous size measurements using mpMRI and USWE with imaging-based 3D-printed patient-specific whole-mount moulds facilitated histopathology as a reference standard. Independent-samples T-tests were used for the continuous variables and a nonparametric Mann-Whitney U test for independent samples was applied to examine the distribution and median differences between mpMRI and USWE groups. RESULTS: A significant number of men had underestimation of prostate cancer using both mpMRI (82.1%; 87/106) and USWE (64.6%; 62/96). On average, tumour size was underestimated by a median size of 7 mm in mpMRI, and 1 mm in USWE. There were 327 cancerous lesions (153 with mpMRI and 174 for USWE). mpMRI and USWE underestimated the majority of cancerous lesions (108/153; 70.6%) and (88/174; 50.6%), respectively. Validation cohort data confirmed these findings MRI had a nearly 20% higher underestimation rate than USWE (χ2 (1, N = 327) = 13.580, p = 0.001); especially in the mid and apical level of the gland. Clinically non-significant cancers were underestimated in significantly higher numbers in comparison to clinically significant cancers. CONCLUSIONS: Size measurement of prostate cancers on preoperative imaging utilising maximum linear extent technique, underestimated the extent of cancer. Further research is needed to confirm our observations using different sequences, methods and approaches for cancer size measurement.

Prostate Cancer Gleason Score From Biopsy to Radical Surgery: Can Ultrasound Shear Wave Elastography and Multiparametric Magnetic Resonance Imaging Narrow the Gap?

OBJECTIVES: To investigate the impact of ultrasound shear wave elastography (USWE) and multiparametric magnetic resonance imaging (mpMRI) in predicting a change in biopsy-assigned Gleason Score (GS) after radical surgery for localised prostate cancer (PCa). METHOD: A total of 212 men opting for laparoscopic radical prostatectomy (LRP) between September 2013 and June 2017 were recruited into this study. All the participants had 12-core transrectal ultrasound (TRUS) biopsies and imaging using USWE and mpMRI before radical surgery. The predictive accuracy for imaging modalities was assessed in relation to upgrading and downgrading of PCa GS between the biopsies and radical prostatectomy using Student's t-test and multivariable logistic regression analyses. A decision analysis curve was constructed assessing the impact of nomogram on clinical situations using different thresholds of upgrading probabilities. RESULTS: Most GS 6 diseases on biopsies were upgraded on radical surgery (37/42, 88.1%). Major downgrading was seen in GS 8 category of disease (14/35; 37.1%), whereas no alteration was observed in GS 7 on biopsies in most men (55/75; 73.3%). In univariate analysis, higher preoperative prostate-specific antigen (PSA) (p = 0.001), higher prostate-specific antigen density (PSAD) (p = 0.002), stiffer USWE lesions (p = 0.009), and higher prostate imaging-reporting and data system (PIRADS) (p = 0.002) on mpMRI were significant predictors of upgrading. In multivariate logistic regression analyses, only PSA (p = 0.016) and USWE-measured tissue stiffness (p = 0.029) showed statistical significance in predicting upgrading. CONCLUSIONS: Measurement of tissue stiffness using USWE in clinically localised PCa can predict upgrading of GS and has the potential to improve patient management options.

Dynamic Recrystallization and Its Effect on Superior Plasticity of Cold-Rolled Bioabsorbable Zinc-Copper Alloys.

High plasticity of bioabsorbable stents, either cardiac or ureteral, is of great importance in terms of implants' fabrication and positioning. Zn-Cu constitutes a promising group of materials in terms of feasible deformation since the superplastic effect has been observed in them, yet its origin remains poorly understood. Therefore, it is crucial to inspect the microstructural evolution of processed material to gain an insight into the mechanisms leading to such an extraordinary property. Within the present study, cold-rolled Zn-Cu alloys, i.e., Zn with addition of 1 wt.% and 5 wt.% of Cu, have been extensively investigated using scanning electron microscopy as well as transmission electron microscopy, so as to find out the possible explanation of superior plasticity of the Zn-Cu alloys. It has been stated that the continuous dynamic recrystallization has a tremendous impact on superior plasticity reported for Zn-1Cu alloy processed by rolling to 90% of reduction rate. The effect might be supported by static recrystallization, provoking grain growth and thereby yielding non-homogeneous microstructures. Such heterogeneous microstructure enables better formability since it increases the mean free path for dislocation movement.

Quantitative ultrasound shear wave elastography (USWE)-measured tissue stiffness correlates with PIRADS scoring of MRI and Gleason score on whole-mount histopathology of prostate cancer: implications for ultrasound image-guided targeting approach.

OBJECTIVE: To correlate quantitative tissue stiffness measurements obtained by transrectal ultrasound shear wave elastography (USWE) with PI-RADS scoring of multiparametric magnetic imaging resonance (mpMRI) using Gleason scores of radical prostatectomy as a reference standard. PATIENTS AND METHODS: 196 men with localised prostate cancer were prospectively recruited into the study and had quantitative prostate tissue stiffness measurements in kilopascals (kPa) using transrectal USWE prior to radical prostatectomy. PI-RADS scores of mpMRI were also obtained in all the men. Imaging and histopathology of radical prostatectomy specimen were oriented to each other using patient specific customised 3D moulds to guide histopathology grossing of radical prostatectomy specimens. All included patients had confirmed PCa on TRUS-guided biopsies, had both USWE and mpMRI imaging data, and underwent radical prostatectomy. Chi-square test with 95% confidence interval was used to assess the difference between Gleason score (GS) of radical prostatectomy and PI-RADS classification, as well as GS of radical prostatectomy and stiffness (in Kpa) using USWE. The correlation coefficient (r) was calculated in order to investigate relation between PI-RADS classification and tissue stiffness in kPa. RESULTS: There was a statistically significant correlation between USWE-measured tissue stiffness and GS (χ2 (2, N = 196) = 23.577, p < 0.001). Also, there was a statistically significant correlation between Gleason score and PI-RADS score (χ2 (2, N = 196) = 12.838, p = 0.002). High PIRADS on MRI and high stiffness on USWE (> 100 kPa) detected more than 80% and 90% high risk prostate cancer disease. However, a weak correlation coefficient of 0.231 was observed between PI-RADS score and level of tissue stiffness measured in kPa. CONCLUSION: Quantitative USWE and mpMRI using PI-RADS classification provide a good degree of prediction for Gleason score of clinically significant prostate cancer (csPCa). Stiffer lesions on ultrasound showed a weak correlation with PI-RADS scoring system. USWE could be used to target suspected prostate cancer.

Enhancing communication between foundation doctors and radiologists: a quality improvement project.

Facilitating radiological imaging for patients is an essential task for foundation year (FY) doctors. Achieving competence in this task can significantly enhance patient management. We evaluated the confidence and skills of FY doctors in facilitating radiological imaging before and after introduction of formal training. Twenty surgical FYs working at a large teaching hospital were surveyed to evaluate their baseline level of competence in booking and discussing imaging with radiology colleagues. Parameters were measured on a Likert scale, including confidence in discussing requests and satisfaction of their own performance following discussions with radiologists. Eight radiology consultants were surveyed to evaluate their opinions on FYs' communication and established areas for improvement. A teaching session was then delivered to improve communication skills. Furthermore, Previous investigation results, Answer you need from the scan, Clinical status and story, Crucial: how urgent is the scan, Safety (PACCSS) poster was introduced to remind the FYs of the salient information required when discussing imaging. One month after the intervention, the initial participants were resurveyed. Based on a 10-point Likert scale, the FYs demonstrated a mean improvement in self-reported confidence (2.1±1.1, p<0.01), and in satisfaction of own performance after a discussion (1.7±1.1, p<0.01). We identified deficiencies in surgical FY doctors' confidence and skills in facilitating radiological imaging. There was a demonstrable benefit with focused training in improving these skills. This could potentially provide significant benefits in patient care and management. Interspecialty communication should be introduced into undergraduate and postgraduate educational curriculum.

Predicting the Performance of Concurrent Systematic Random Biopsies during Image Fusion Targeted Sampling of Multi-Parametric MRI Detected Prostate Cancer. A Prospective Study (PRESET Study).

The study was aimed to develop a predictive model to identify patients who may benefit from performing systematic random biopsies (SB) in addition to targeted biopsies (TB) in men suspected of having prostate cancer. A total of 198 patients with positive pre-biopsy MRI findings and who had undergone both TB and SB were prospectively recruited into this study. The primary outcome was detection rates of clinically significant prostate cancer (csPCa) in SB and TB approaches. The secondary outcome was net clinical benefits of SB in addition to TB. A logistic regression model and nomogram construction were used to perform a multivariate analysis. The detection rate of csPCa using SB was 51.0% (101/198) compared to a rate of 56.1% (111/198) for TB, using a patient-based biopsy approach. The detection rate of csPCa was higher using a combined biopsy (64.6%; 128/198) in comparison to TB (56.1%; 111/198) alone. This was statistically significant (p < 0.001). Age, PSA density and PIRADS score significantly predicted the detection of csPCa by SB in addition to TB. A nomogram based on the model showed good discriminative ability (C-index; 78%). The decision analysis curve confirmed a higher net clinical benefit at an acceptable threshold.

Prediction of prostate cancer Gleason score upgrading from biopsy to radical prostatectomy using pre-biopsy multiparametric MRI PIRADS scoring system.

An increase or 'upgrade' in Gleason Score (GS) in prostate cancer following Transrectal Ultrasound (TRUS) guided biopsies remains a significant challenge to overcome. to evaluate whether MRI has the potential to narrow the discrepancy of histopathological grades between biopsy and radical prostatectomy, three hundred and thirty men treated consecutively by laparoscopic radical prostatectomy (LRP) between July 2014 and January 2019 with localized prostate cancer were included in this study. Independent radiologists and pathologists assessed the MRI and histopathology of the biopsies and prostatectomy specimens respectively. A multivariate model was constructed using logistic regression analysis to assess the ability of MRI to predict upgrading in biopsy GS in a nomogram. A decision-analysis curve was constructed assessing impact of nomogram using different thresholds for probabilities of upgrading. PIRADS scores were obtained from MRI scans in all the included cases. In a multivariate analysis, the PIRADS v2.0 score significantly improved prediction ability of MRI scans for upgrading of biopsy GS (p = 0.001, 95% CI [0.06-0.034]), which improved the C-index of predictive nomogram significantly (0.90 vs. 0.64, p < 0.05). PIRADS v2.0 score was an independent predictor of postoperative GS upgrading and this should be taken into consideration while offering treatment options to men with localized prostate cancer.

Anisotropy of Mechanical Properties of Pinctada margaritifera Mollusk Shell.

The mechanical properties such as compressive strength and nanohardness were investigated for Pinctada margaritifera mollusk shells. The compressive strength was evaluated through a uniaxial static compression test performed along the load directions parallel and perpendicular to the shell axis, respectively, while the hardness and Young modulus were measured using nanoindentation. In order to observe the crack propagation, for the first time for such material, the in-situ X-ray microscopy (nano-XCT) imaging (together with 3D reconstruction based on the acquired images) during the indentation tests was performed. The results were compared with these obtained during the micro-indentation test done with the help of conventional Vickers indenter and subsequent scanning electron microscopy observations. The results revealed that the cracks formed during the indentation start to propagate in the calcite prism until they reach a ductile organic matrix where most of them are stopped. The obtained results confirm a strong anisotropy of both crack propagation and the mechanical strength caused by the formation of the prismatic structure in the outer layer of P. margaritifera shell.

A multicentre parallel-group randomised trial assessing multiparametric MRI characterisation and image-guided biopsy of prostate in men suspected of having prostate cancer: MULTIPROS study protocol.

BACKGROUND: There is growing evidence suggesting that multiparametric magnetic resonance imaging (mpMRI) is a marker for prostate cancer (PCa) aggressiveness and could be used to plan treatment. Improving early detection of clinically significant PCa with pre-biopsy mpMRI would very likely have advantages including optimising the diagnosis and treatment of diseases and diminishing patient anxiety. METHODS AND MATERIALS: This is a prospective multicentre study of pre-biopsy mpMRI diagnostic test accuracy with subgroup randomisation at a 1:1 ratio with respect to transrectal ultrasound (TRUS) and MRI/US fusion-guided biopsy or TRUS-only biopsy. It is designed as a single-gate study with a single set of inclusion criteria. The total duration of the recruitment phase was 48 months; however, this has now been extended to 66 months. A sample size of 600 participants is required. DISCUSSION: The primary objective is to determine whether mpMRI can improve PCa detection and characterisation. The key secondary objective is to determine whether MRI/US fusion-guided biopsy can reduce the number of false-negative biopsies. Ethical approval was obtained from the East of Scotland Research Ethics Committee 1 (14/ES/1070) on 20 November 2014. The results of this study will be used for publication and presentation in national and international journals and at scientific conferences. TRIAL REGISTRATION: ClinicalTrials.gov, NCT02745496. Retrospectively registered on 20 April 2016.

Prediction of Postprostatectomy Biochemical Recurrence Using Quantitative Ultrasound Shear Wave Elastography Imaging.

Objectives: To determine the prognostic significance of tissue stiffness measurement using transrectal ultrasound shear wave elastography in predicting biochemical recurrence following radical prostatectomy for clinically localized prostate cancer. Patients and Methods: Eligible male patients with clinically localized prostate cancer and extraperitoneal laparoscopic radical prostatectomy between November 2013 and August 2017 were retrospectively selected. Information of potential biochemical recurrence predictors, including imaging (ultrasound shear wave elastography and magnetic resonance imaging), clinicopathological characteristics, and preoperative prostate specific antigen (PSA) levels were obtained. Recurrence-free survival (Kaplan-Meier curve) and a multivariate model were constructed using Cox regression analysis to evaluate the impact of shear wave elastography as a prognostic marker for biochemical recurrence. Results: Patients experienced biochemical recurrence in an average of 26.3 ± 16.3 months during their follow-up. A cutoff of 144.85 kPa for tissue stiffness measurement was estimated for recurrence status at follow-up with a sensitivity of 74.4% and a specificity of 61.7%, respectively (p < 0.05). In univariate analysis, shear wave elastography performed well in all preoperative factors compared to biopsy Gleason Score, PSA and magnetic resonance imaging; in multivariate analysis with postoperative pathological factors, shear wave elastography was statistically significant in predicting postoperative biochemical recurrence, which improved the C-index of predictive nomogram significantly (0.74 vs. 0.70, p < 0.05). Conclusions: The study revealed that quantitative ultrasound shear wave elastography-measured tissue stiffness was a significant imaging marker that enhanced the predictive ability with other clinical and histopathological factors in prognosticating postoperative biochemical recurrence following radical prostatectomy for clinically localized prostate cancer.

Periprostatic fat adipokine expression is correlated with prostate cancer aggressiveness in men undergoing radical prostatectomy for clinically localized disease.

OBJECTIVES: To investigate the relationship between periprostatic adipose tissue (PPAT) adipokine expression and prostate cancer (PCa) aggressiveness using both pathological features of radical prostatectomy (RP) and multiparametric magnetic resonance imaging ( MRI) variables. PATIENTS AND METHODS: Sixty-nine men were recruited to assess immunohistochemical expression of tumour necrosis factor (TNF)α and vascular endothelial growth factor (VEGF) of periprostatic fat of RP specimens. Per cent immunopositivity was quantified on scanned slides using the Aperio Positive Pixel Count algorithm for PPAT TNFα, VEGF and androgen receptors. Periprostatic fat volume (PFV) was segmented on contiguous T1 -weighted axial MRI slices from the level of the prostate base to apex. PFV was normalized to prostate volume (PV) to account for variations in PV (normalized PFV = PFV/PV). MRI quantitative values (Kep , Ktrans and apparent diffusion coefficient) were measured from the PCa primary lesion using Olea Sphere software. Patients were stratified into three groups according to RP Gleason score (GS): ≤6, 7(3 + 4) and ≥7(4 + 3). RESULTS: The mean rank of VEGF and TNFα was significantly different between the groups [H(2) = 11.038, P = 0.004] and [H(2) = 13.086, P = 0.001], respectively. Patients with stage pT3 had higher TNFα (18.2 ± 8.95) positivity than patients with stage pT2 (13.27 ± 10.66; t [67] = -2.03, P = 0.047). TNFα expression significantly correlated with Ktrans (ρ = 0.327, P = 0.023). TNFα (P = 0.043), and VEGF (P = 0.02) correlated with high grade PCa (GS ≥ 7) in RP specimens and also correlated significantly with upgrading of GS from biopsy to RP histology. CONCLUSIONS: The expression levels of TNFα and VEGF on immunostaining significantly correlated with aggressivity of PCa. As biomarkers, these indicate the risk of having high grade PCa in men undergoing RP.

Diagnostic accuracy of image-guided biopsies in small (<4 cm) renal masses with implications for active surveillance: a systematic review of the evidence.

OBJECTIVE:: To determine the safety and diagnostic accuracy of renal tumour biopsies in a defined population of small renal masses (SRMs) only <4 cm using 3 × 2 table, intention to diagnose approach. 3 × 2 table approach examines indeterminate results as a separate category rather than pushing these through traditional 2 × 2 table (four-cell matrix) approach. METHODS:: A highly sensitive search was performed in the Cochrane Library, Database of Abstracts of Reviews of Effects; MEDLINE and MEDLINE in Process, EMBASE and conference proceedings (1966-2016) for the acquisition of data on the diagnostic accuracy and complications of RTB in patients with SRM <4 cm. Methodological quality and risk of bias was assessed using QUADAS-2. Test characteristics were calculated using conventional 2 × 2 contingency table analysis excluding non-diagnostic biopsies, and an intention-to-diagnose approach with a 3 × 2 table for pooled estimates of the sensitivity and specificity. RESULTS:: A total of 20 studies were included with a total sample size of 974. The pooled estimates for sensitivity and specificity of RTB based upon univariate analysis using 2 × 2 table observed sensitivity 0.952 [confidence interval (CI) 0.908-0.979] and specificity 0.824 (CI 0.566-0.962). Using the 3 × 2 table and intention-to-diagnose principle, sensitivity 0.947 (CI 0.925-0.965) and specificity 0.609 (CI 0.385-0.803) decreased. CONCLUSION:: RTB in SRMs (<4 cm) is associated with a high diagnostic sensitivity but poor specificity when non-diagnostic results are included by a 3 × 2 table for analysis (intention to diagnose approach). Risk of non-diagnostic results and poor quality of research need addressing through future studies, preferably by a well-designed prospective study appropriately powered for diagnostic accuracy using valid reference standards. ADVANCES IN KNOWLEDGE:: A comprehensive synthesis of literature on image-guided biopsies in SRMs using a different methodology and study design.

Quantitative transrectal shear wave elastography undergoing salvage extraperitoneal laparoscopic radical prostatectomy following failed radiotherapy.

BACKGROUND: To evaluate pre-surgical quantitative transrectal shear wave elastography (SWE) in the detection and characterisation of radioresistant prostate cancer. METHODS: Twelve men with recurrent prostate cancer following external beam radiotherapy were included in a prospective protocol-driven study. All underwent MR imaging and quantitative shear wave elastographic assessment of recurrent disease prior to salvage laparoscopic radical prostatectomy procedures. Images were used to construct 3D mold printing and histopathological processing of surgical specimen. Statistical analyses including ROC were generated using software programmes. RESULTS: There were 48 cancer foci identified on final histopathology using patient-specific mold-based approach in 12 patients. Mean number of lesion was 3.4 (range 2-4). Quantitative transrectal SWE showed a sensitivity and specificity 0.77 (95% CI 0.627-0.880) and 0.82 (95% CI 0.642-0.942), respectively. The diagnostic accuracy increased with increasing size of the lesions with overall AUC of 0.89. CONCLUSIONS: In our series, quantitative transrectal SWE showed a good diagnostic accuracy in the detection and characterisation of recurrent prostate cancer following failed radiotherapy treatment. These findings may help in targeting biopsies or future focal treatment options.

Quantitative parameters in dynamic contrast-enhanced magnetic resonance imaging for the detection and characterization of prostate cancer.

OBJECTIVES: to assess the diagnostic accuracy of quantitative parameters of DCE-MRI in multi-parametric MRI (mpMRI) in comparison to the histopathology (including Gleason grade) of prostate cancer. PATIENTS AND METHODS: 150 men with suspected prostate cancer (abnormal digital rectum examination and or elevated prostate-specific antigen) received pre-biopsy 3T mpMRI and were recruited into peer-reviewed, protocol-based prospective study. The DCE-MRI quantitative parameters (Ktrans (influx transfer constant) and kep (efflux rate constant)) of the cancerous and normal areas were recorded using four different kinetic models employing Olea Sphere (Olea Medical, La Ciotat, France). The correlation between these parameters and the histopathology of the lesions (biopsy and in a sub-cohort 41 radical prostatectomy specimen) was assessed. RESULTS: The quantitative parameters showed a significant difference between non-cancerous (benign) and cancerous lesions (Gleason score≥3+3) in the prostate gland. The cut-off values for prostate cancer differentiation were: Ktrans (0.205 min-1) and kep (0.665 min-1) in the extended Tofts model (ET) and Ktrans (0.205 min-1 and kep (0.63 min-1) in the Lawrence and Lee delay (LD) models respectively. The mean Ktrans value also showed a difference between low-grade cancer (Gleason score=3+3) and high-grade cancer (Gleason score ≥ 3+4). With the addition of DCE-MRI quantitative parameters, the sensitivity of the PIRAD scoring system was increased from 56.6% to 92.1% (Ktrans _ET), 93.1% (kep _ET), 91.0%, (Ktrans _LD) and 89.4% (kep _LD). CONCLUSION: Quantitative DCE-MRI parameters improved the diagnostic performance of conventional MRI in distinguishing normal and prostate cancers, including characterization of grade of cancers. The ET and LD models in post-image processing analysis provided better cut-off values for prostate cancer differentiation than the other quantitative DCE-MRI parameters.

Performance Characteristics of Transrectal Shear Wave Elastography Imaging in the Evaluation of Clinically Localized Prostate Cancer: A Prospective Study.

PURPOSE: We tested the diagnostic accuracy of shear wave elastography to detect and phenotypically characterize prostate cancer compared with whole mount radical prostatectomy histopathology. MATERIALS AND METHODS: In this prospective, protocol driven, diagnostic accuracy study 212 consecutive men undergoing laparoscopic radical prostatectomy for clinically localized prostate cancer were recruited. Quantitative stiffness data on the prostate gland were obtained in each patient using an endocavitary transrectal transducer before laparoscopic radical prostatectomy. Those data were compared with a detailed histopathological examination of the radical prostatectomy specimen using 3-dimensional printing mold based technology to ensure an improved image histology orientation. ROC curves were assessed between the groups. RESULTS: Quantitative stiffness data estimated in kPa were significantly higher in malignant compared with benign areas. At a cutoff of 82.6 kPa the sensitivity and specificity of shear wave elastography were 96.8% and 67.8%, respectively (p <0.01). Significant differences were observed for different cancer grades with the Young moduli, including 91.6, 102.3 and 131.8 kPa for low grade (Gleason score 6), intermediate grade (Gleason score 7) and high grade (Gleason score 8 or greater) prostate cancer, respectively (p <0.05). Shear wave elastography also detected capsular breaches with significant prediction of prostate cancer pathological staging. Potential limitations include selection bias and study being single center site. CONCLUSIONS: Quantitative shear wave elastography via the transrectal approach accurately detected cancer foci and revealed significant differences between cancerous and benign tissue. Moreover, this technique can be used to reliably phenotype prostate cancer aggressiveness.

Normalized periprostatic fat MRI measurements can predict prostate cancer aggressiveness in men undergoing radical prostatectomy for clinically localised disease.

Periprostatic and pelvic fat have been shown to influence prostate cancer behaviour through the secretion of chemokines and growth factors, acting in a paracrine mode. We have measured periprostatic fat volume (PFV) with normalisation to prostate gland volume on pelvic magnetic resonance imaging (MRI) and have correlated this with grade (Gleason score; GS) and pathological staging (pT) of prostate cancer (PCa) following radical prostatectomy (RP). PFV was determined using a segmentation technique on contiguous T1-weighted axial MRI slices from the level of the prostate base to the apex. The abdominal fat area (AFA) and subcutaneous fat thickness (SFT) were measured using T1-weighted axial slices at the level of the umbilicus and the upper border of the symphysis pubis, respectively. PFV was normalised to prostate volume (PV) to account for variations in PV (NPFV = PFV/PV). Patients were stratified into three risk groups according to post-operative GS: ≤6, 7(3 + 4), and ≥7(4 + 3). NPFV was significantly different between the groups (p = 0.001) and positively correlated with post-operative GS (ρ = 0.294, p < 0.001). There was a difference in NPFV between those with upgrading of GS from 6 post prostatectomy (2.43 ± 0.98; n = 26) compared to those who continued to be low grade (1.99 ± 0.82; n = 17); however, this did not reach statistical significance (p = 0.11).