Characterisation of Prostate Lesions Using Transrectal Shear Wave Elastography (SWE) Ultrasound Imaging: A Systematic Review

Abstract

Background: ultrasound-based shear wave elastography (SWE) can non-invasively assess prostate tissue stiffness. This systematic review aims to evaluate SWE for the detection of prostate cancer (PCa) and compare diagnostic estimates between studies reporting the detection of all PCa and clinically significant PCa (csPCa).

Methods: a literature search was performed using the MEDLINE, EMBASE, Cochrane Library, ClinicalTrials.gov, and CINAHL databases. Studies evaluating SWE for the detection of PCa using histopathology as reference standard were included.

Results: 16 studies including 2277 patients were included for review. Nine studies evaluated SWE for the detection of PCa using systematic biopsy as a reference standard at the per-sample level, with a pooled sensitivity and specificity of 0.85 (95% CI = 0.74-0.92) and 0.85 (95% CI = 0.75-0.91), respectively. Five studies evaluated SWE for the detection of PCa using histopathology of radical prostatectomy (RP) specimens as the reference standard, with a pooled sensitivity and specificity of 0.71 (95% CI = 0.55-0.83) and 0.74 (95% CI = 0.42-0.92), respectively. Sub-group analysis revealed a higher pooled sensitivity (0.77 vs. 0.62) and specificity (0.84 vs. 0.53) for detection of csPCa compared to all PCa among studies using RP specimens as the reference standard.

Conclusion: SWE is an attractive imaging modality for the detection of PCa.

Keywords: prostate cancer; shear wave elastography; ultrasound.

Figure 1

Flow chart detailing the process of study inclusion in the review.

Figure 2

Methodological quality assessment, with respect to risk of bias and applicability concerns, of the included studies, according to the revised Quality Assessment of Diagnostic Accuracy Studies (QUADAS-2) tool.

Figure 3

Studies evaluating SWE for the detection of prostate cancer with the histopathology of SB as a reference standard. (a) Forest plot for per-sample level analysis. (b) Forest plot for per-patient level analysis. (c) Hierarchical summary receiver operating characteristic (HSROC) curves (solid lines), for per-patient (red) and per-sample (blue) level analyses, corresponding to the pooled sensitivity and false positive rate values, indicated by the solid red and blue circles, with 95% confidence intervals about the pooled results shown by the dashed lines; the open triangles refer to individual studies.

Figure 4

Studies evaluating SWE at the per-tissue level for the detection of prostate cancer with histopathology of radical prostatectomy (RP) specimens as the reference standard. (a) Forest plot and (b) HSROC curve corresponding to the pooled sensitivity and false positive rate value indicated by the solid black circle, with 95% confidence intervals about the pooled result shown by the dashed line; the open triangles refer to individual studies.

Figure 5

Funnel plot to assess for publication bias in studies evaluating SWE for the detection of prostate cancer at the sample level, with either SB or whole-mount histopathology of the RP specimen as the reference standard.