Value of shear wave elastography for diagnosis of primary prostate cancer: a systematic review and meta-analysis

Abstract

Aim: To evaluate the difference in stiffness between prostate cancer (PCa) and benign tissue based on Young’s modulus determined by shear wave elastography (SWE). In addition, the diagnostic accuracy of SWE for the detection of PCa was evaluated comprehensively.Material and methods: We conducted our systematic review and meta-analysis based on databases of PubMed, Embase and Web of Science. Relevant studies regarding to the diagnostic accuracy of SWE for detecting PCa compared to a reference standard of histopathology were included. The pooled weighted mean difference (WMD) of Young’s modulus, sensitivity (SEN) and specificity (SPE), and area under the curve (AUC) were calculated using Stata software.Results: Based on our search strategy, 9 studies were ultimately included. The pooled results indicated that the mean Young’s modulus for detecting prostate cancer was significantly higher than that for prostate benign tissue (WMD = 38.01, 95%CI = 25.59–50.44, p<0.01). In addition, the pooled SEN was 0.86 (95%CI = 0.75–0.92), and the SPE was 0.89 (95%CI = 0.82–0.93). Moreover, an overall high degree of accuracy was indicated by the summary receiver operator characteristic curve with an AUC of 0.94 (95%CI = 0.91–0.95).Conclusion: Our study indicated that SWE is a useful technique for differentiating PCa and benign tissue with a high degree of diagnostic accuracy.

Causal contributors to tissue stiffness and clinical relevance in urology

“…Aging, neoplasia, and metabolic diseases can lead to fibrosis and an increase of tissue stiffness 5 . Thus, tissue stiffness is a clinically relevant parameter for diagnosis and prognosis purposes, as we have here shown that alteration of this mechanical parameter is coupled with the progression of diseases and malignancies associated with kidney cancer and fibrosis 143 , PCa 177 , 178 , bladder cancer 167 , testicular cancer 189 , and infertility related diseases 190 – 192 . Biochemical, topographical, and mechanical modification of the ECM occurs both at the primary and metastatic site 19 , 21 , 26 , but there is also an important cellular contribution to the altered tissue stiffness by means of cell density, contractility, and traction 82 , 93 .…”

“…PCa has a higher cell and vessel density, which is discernibly stiffer than both benign and normal tissues 177 . Given the noninvasive and cost-effective imaging technology of SWE, several studies have been published aiming to evaluate differences in stiffness between PCa and benign tissue based on Young’s modulus 178 (Table 2 ). For all studies discussed here, it was reported that the SWE-obtained Young’s modulus of PCa was significantly higher for benign prostate tissue.…”

“…For all studies discussed here, it was reported that the SWE-obtained Young’s modulus of PCa was significantly higher for benign prostate tissue. The stiffness of PCa in the peripheral area, where most PCa starts, gradually increases with the Gleason Score, which is the grade of the tumor: the higher the Gleason score, the stiffer the tissue is 178 , 179 . The stiffness values corresponding to each Gleason score differ when reported by different studies.…”

Prostate Cancer Ultrasound: Is Still a Valid Tool?

“…Correas et al, for example, in a study of 184 patients, established an elasticity threshold of 35-37 kPa [34], unlike Boehm et al which placed the threshold at a higher elasticity value of approximately 50 kPa [46]. However, apart from these differences, high percentages (over 70-80%) have always been found in terms of diagnostic accuracy, sensitivity, specificity, and negative predictive value, which confirmed the correlation between tissue rigidity and malignancy, which was always confirmed by the outcome of the histological examination [47]. In a study of 50 patients undergoing SWE-guided target biopsy on highly suspicious lesions, Ahmad et al report a specificity of 88% and a sensitivity of 90% in patients with PSA less than 20 mg/L and much higher values, both of about 93%, for PSA above 20 mg/L.…”

Artificial Intelligence System for Predicting Prostate Cancer Lesions from Shear Wave Elastography Measurements

“…The most important limitation of 2D-SWE is represented by its low performance in detecting tumors smaller than 5 mm [ 42 ]. Moreover, in order to determine the true sensitivity and specificity of the method, a correlation with histo-pathological sections of radical prostatectomy specimens is finally required [ 43 ]. A further limitation of the technique is represented by the operator subjectivity in detecting prostate areas with high rigidity.…”