Novel application of three-dimensional shear wave elastography in the detection of clinically significant prostate cancer.

The present study evaluated three-dimensional shear wave elastography (3D SWE) in the detection of clinically significant prostate cancer. Clinically significant prostate cancer was defined by a minimum of one biopsy core with a Gleason score of 3+4 or 6 with a maximum cancer core length >4 mm. Patients with serum prostate-specific antigen levels of 4.0-20.0 ng/ml who were suspected of having prostate cancer from multi-parametric magnetic resonance imaging (mpMRI) were prospectively recruited. The 3D SWE was performed pre-biopsy, after which patients underwent MRI-transrectal ultrasound image-guided targeted biopsies for cancer-suspicious lesions and 12-core systematic biopsies. The pathological biopsy results were compared with the mpMRI and 3D SWE images. A total of 12 patients who were suspected of having significant cancer on mpMRI were included. The median pre-biopsy PSA value was 5.65 ng/ml. Of the 12 patients, 10 patients were diagnosed as having prostate cancer. In the targeted biopsy lesions, there was a significant difference in Young's modulus between the cancer-detected area (median 64.1 kPa, n=20) and undetected area (median 30.8 kPa, n=8; P<0.0001). On evaluation of receiver operating characteristics, a cut-off value of the Young's modulus of 41.0 kPa was used for the detection of clinically significant cancer, with which the sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of cancer detection were 58, 97, 86 and 87%, respectively. When combining this cut-off tissue elasticity value with Prostate Imaging Reporting and Data System (PI-RADS) scores, the sensitivity, specificity, positive predictive value and negative predictive value of cancer detection were improved to 70, 98, 91 and 92%, respectively. In the cancer-detected lesions, a significant correlation was identified between the tissue elasticity value of the lesions and Gleason score (r=0.898, P<0.0001). In conclusion, PI-RADS combined with measurement of Young's modulus by 3D SWE may improve the diagnosis of clinically significant prostate cancer.