Role of Transrectal Ultrasound Elastography in the Diagnosis of Prostate Carcinoma

BACKGROUND: The purpose of this study was to evaluate the diagnostic value of transrectal real- time strain elastography (RTE) in identifying prostatic carcinoma (PCa). METHODS: 60 patients suspected of having PCa based on abnormal digital rectal examination and raised prostate specific antigen levels underwent transrectal ultrasound (TRUS), color Doppler (CD) and RTE. Elastograms were scored on a five point scale based on distribution of strain in relation to hypoechoic area on TRUS. Twelve core systematic biopsy as well as targeted biopsy was performed from suspicious areas on TRUS and RTE. Diagnostic performance of sonoelastography was evaluated using histopathology as reference standard. RESULTS: Histopathology revealed cancer in 28 out of 60 patients (47%) studied. Gleason score ranged from 6 to 9. The sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of TRUS in detecting prostate cancer were 78.57%, 81.25%, 78.57%, and 81.25%, respectively. On CD evaluation 87.5% (n = 28) of benign lesions showed symmetric, radial flow compared to 14.3% (n = 4) of malignant lesions (P < 0.0001). The sensitivity and specificity of RTE was 89.29% and 56.25% with PPV and NPV being 58.13% and 82.35%, respectively. Higher elastography score was found to be significantly associated with malignant histopathology (P = 0.004). Cancer detection rate with RTE was greater for tumors with higher Gleason score. CONCLUSION: RTE was found to have better sensitivity than TRUS as well as combination of TRUS and CD. Although less specific, RTE can be an effective adjuvant tool to TRUS for guidance of biopsy and improve detection rate of PCa.