Transrectal ultrasound shear wave elastography for distinguishing prostate cancer from benign tissue

Objective: To discuss the value of transrectal ultrasound shear wave elastography (SWE) in the differential diagnosis of prostate cancer and benign tissue. Methods: A total of 31 patients with external gland nodules of prostate identified by transrectal ultrasound or MRI, with abnormal results after digital rectal examination, or with increased serum levels of PSA, were included in this study and examined with SWE and biopsy. SWE was performed by two senior sonographers. According to the pathological results, the patients were assigned into the prostate cancer group or the benign group. A total of 249 biopsies were sampled, with an average of 8.03 biopsies per patient, and 133 biopsies detected cancer and 116 were benign or without cancer.The elasticity moduli Emean, Emax and Emin were compared between the two groups. Results: The Emean, Emax and Emin in the cancer group were significantly higher than those in the hyperplasia group. When Emean = 39.65kPa, the sensitivity, specificity, Youden Index, positive predictive value (PPV) and negative predictive value (NPV) for prostate cancer diagnosis were 82.57%, 88.03%, 70.61%, 88.61% and 81.74%, respectively; when Emax = 52.2kPa, the sensitivity, specificity, Youden Index, PPV and NPV were 89.39%, 73.5%, 62.9%, 79.19% and 86%, respectively; and with Emin = 30.3kPa, the sensitivity, specificity and Youden Index were 43.6%, 30.2% and 13.4%, respectively. Conclusion: Prostate cancer and benign tissue was significantly different on SWE images. Hence, SWE might help to differentially diagnose prostate cancer and benign tissue.