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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. Key points: The study assessed size of prostate cancer on MRI and ultrasound shear wave elastography (USWE) and compared with size on microscopic examination (histopathology) after radical prostatectomy. In comparison to histopathology, there was significant underestimation of prostate cancer size by imaging using MRI and USWE. Specific message is for men opting for focal treatment of prostate cancer [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

This exploratory study investigates the cost-effectiveness of ultrasound shear wave elastography (SWE) imaging in comparison to pre-biopsy multiparametric magnetic resonance imaging (mpMRI) in men with suspected prostate cancer. This research is motivated by the early evidence of the good performance of SWE in distinguishing cancerous from benign prostate tissues. We used a decision analysis model representing the care-pathways of men referred with a high prostate specific antigen (PSA) and/or abnormal digital rectal examination (DRE) in a UK setting from the payer's perspective with results reported in 2016 GBP. We then appraised the cost-effectiveness of a novel approach based on SWE compared to the more conventional and widely practiced mpMRI-based approaches using data reported in the literature. Deterministic and probabilistic sensitivity analyses were used to address uncertainty regarding the parameter values utilised. Our exploratory results implied that SWE approach yielded an additional quality-adjusted life year (QALY) at the cost of GBP 10,048 compared to the standard mpMRI-based approach in the UK. This is lower than the official willingness to pay threshold of GBP 20,000 (the UK healthcare system guidelines) and is therefore a suitable replacement for the current practice. Sensitivity analyses confirmed the robustness of our results. [ABSTRACT FROM AUTHOR]

Background: Shear wave imaging (SWI) is a new ultrasound technique whose application facilitates quantitative tissue elasticity assessment during transrectal ultrasound biopsies of the prostate gland. The aim of this study was to determine whether SWI quantitative data can differentiate between benign and malignant areas within prostate glands in men suspected of prostate cancer (PCa). Methods: We conducted a protocol-based, prospective, prebiopsy quantitative SWI of prostate glands in 50 unscreened men suspected of prostate cancer between July 2011 and May 2012. The ultrasound image of whole prostate gland was arbitrarily divided into 12 zones for sampling biopsies, as is carried out in routine clinical practice. Each region was imaged by grey scale and SWI imaging techniques. Each region was further biopsied irrespective of findings of grey scale or SWI on ultrasound. Additional biopsies were taken if SWI abnormal area was felt to be outside of these 12 zones. Quantitative assessment of SWI abnormal areas was obtained in kilopascals (kPa) from abnormal regions shown by SWI and compared with histopathology. Sensitivity, specificity, positive and negative predictive values, and likelihood ratios were calculated for SWI (histopathology was a reference standard). Results: Fifty patients, with a mean age of 69 ± 6.2 years, were recruited into the study. Thirty-three (66 %) patients were diagnosed with PCa, while an additional 4 (8 %) had atypia in at least one of the 12 prostate biopsies. Thirteen (26 %) patients had a benign biopsy. Data analysed per core for SWI findings showed that for patients with PSA <20 μg/L, the sensitivity and specificity of SWI for PCa detection were 0.9 and 0.88, respectively, while in patients with PSA >20 μg/L, the sensitivity and specificity were 0.93 and 0.93, respectively. In addition, PCa had significantly higher stiffness values compared to benign tissues ( p <0.05), with a trend toward stiffness differences in different Gleason grades. Conclusion: SWI provides quantitative assessment of the prostatic tissues and, in our preliminary observation, provides better diagnostic accuracy than grey-scale ultrasound imaging. [ABSTRACT FROM AUTHOR]

Purpose: Quantification of stiffness changes may provide important diagnostic information and aid in the early detection of cancers. Shear wave elastography is an imaging technique that assesses tissue stiffness using acoustic radiation force as an alternate to manual palpation reported previously with quasistatic elastography. In this study, the elastic properties of tissue mimicking materials, including agar, polyacrylamide (PAA), and silicone, are evaluated with an objective to determine material characteristics which resemble normal and cancerous prostate tissue. Methods: Acoustic properties and stiffness of tissue mimicking phantoms were measured using compressional mechanical testing and shear wave elastography using supersonic shear imaging. The latter is based on the principles of shear waves generated using acoustic radiation force. The evaluation included tissue mimicking materials (TMMs) within the prostate at different positions and sizes that could mimic cancerous and normal prostate tissue. Patient data on normal and prostate cancer tissues quantified using biopsy histopathology were used to validate the findings. Pathologist reports on histopathology were blinded to mechanical testing and elastographic findings. Results: Young's modulus values of 86.2 ± 4.5 and 271.5 ± 25.7 kPa were obtained for PAA mixed with 2% Al2O3 particles and silicone, respectively. Young's modulus of TMMs from mechanical compression testing showed a clear trend of increasing stiffness with an increasing percentage of agar. The silicone material had higher stiffness values when compared with PAA with Al2O3. The mean Young's modulus value in cancerous tissue was 90.5 ± 4.5 kPa as compared to 93.8 ± 4.4 and 86.2 ± 4.5 kPa obtained with PAA with 2% Al2O3 phantom at a depth of 52.4 and 36.6 mm, respectively. Conclusions: PAA mixed with Al2O3 provides the most suitable tissue mimicking material for prostate cancer tumor material, while agar could form the surrounding background to simulate normal prostate tissue. [ABSTRACT FROM AUTHOR]