New aspects in shear-wave elastography of prostate cancer

Abstract

AimThis study was designed to evaluate the performance of shear-wave elastography as a diagnostic tool for prostate cancer in a larger cohort of patients than previously reported.Patients and methodsSeventy-three patients with suspected prostate carcinoma were investigated by ultrasound elastography followed by directed biopsy. The elastographic and histological results for all biopsies were compared.ResultsAfter exclusion of invalid and non-assessable results, 794 samples were obtained for which both a histological assessment and an elastometric result (tissue stiffness in kPa) were available: according to the histology 589 were benign and 205 were malignant. Tissue elasticity was found to be weakly correlated with patient's age, PSA level and gland volume. ROC analysis showed that, for the set of results acquired, elastometry did not fulfil literature claims that it could identify malignant neoplasia with high sensitivity and specificity. However, it did show promise in distinguishing between Gleason scores ≤6 and >6 when malignancy had already been identified. Unexpected observations were the finding of a smaller proportion of tumours in the lateral regions of the prostate than generally expected, and also the observation that the elasticity of benign prostate tissue is region-sensitive, the tissue being stiffest in the basal region and more elastic at the apex.ConclusionsShear-wave elastography was found to be a poor predictor of malignancy, but for malignant lesions an elasticity cut-off of 80 kPa allowed a fairly reliable distinction between lesions with Gleason ≤6 and those with Gleason >6. We demonstrate an increase in elasticity of benign prostate tissue from the basal to the apical region.

An experimental study: quantitatively evaluating the change of the content of collagen fibres in penis with two-dimensional ShearWave™ Elastography

“…As SWV is determined by the component and content of tissue, in theory, 2D‐SWE can be used to evaluate the component and content of tissue. At present, studies have shown that 2D‐SWE could detect the change of component and content of thyroid, breast, liver and prostate and so on (Berg et al., ; Cassinotto et al., ; Guibal et al., ; Magri et al., ; Porsch et al., ; Tanter et al., ; Veyrieres et al., ), but the research on using 2D‐SWE to evaluate the change of the content of collagen fibres in penis has not been reported. Age is one of the factors that could induce the change of the content of collagen fibres in penis.…”

Elastografia fali poprzecznej nie pozwala na odróżnienie zmian w sterczu o charakterze złośliwym i łagodnym – analiza porównawcza wyników biopsji, badania histopatologicznego i elastografii

“…The prostate glands were divided notionally into 12 regions of approximately equal volume (details are given elsewhere ( 1 ) ; for a summary see Fig. 1 ).…”

“…This information is color-coded and overlaid on the B-mode image of the prostate in real time. An elastometric analysis of all the regions of the prostate glands has been described in an earlier publication ( 1 ) ; here, we focus on the ten patients in whom the radical prostatectomy allowed a detailed, region-by-region comparison between histological and elastometric results. It was previously reported that elasticity is a weak criterion for distinguishing between benign and malignant prostate tissue, as well as between different D’Amico risk groups or Gleason scores, respectively ( 1 ) .…”

“…The more recent is shear-wave elastography (SWE) ( 4 ) in which an ultrasound probe sends a transverse wave into the tissue and detects the reflected wave, thus measuring the tissue’s distribution of elasticity in three dimensions and allowing this to be displayed by a computer-generated color map ( 5 ) , potentially showing any malignant growth, prostatitis or benign enlarged prostate nodules. SWE has shown promising preliminary results in the detection of prostate cancers and the assessment of their malignity in small-scale studies ( 6 , 7 ) and in larger cohorts of patients ( 1 , 8 ) .…”

Elastography in prostate gland imaging and prostate cancer detection

“…The sensitivity and specificity of systematic biopsy were improved by 31% (94% vs 63 %) and by 10% (92% vs 82%) respectively, after addition of elastography to standard biopsy protocols. Interestingly, Porsch et al unexpectedly showed a poor prediction rate of malignancy by SWE and demonstrated a significant increase in elasticity of benign prostate tissue from the basal to the apical region [56].…”