Diagnostic performance of multiple ultrasonic modalities for prostate cancer.

OBJECTIVE

To evaluate the performance of Grayscale Ultrasound (GSU), Color Doppler Ultrasound/Power Doppler Ultrasound (CDU/PDU), Transrectal Real-Time Tissue Elastography (TRTE) and Contrast-Enhanced Ultrasound (CEUS) in the diagnosis of Prostate Cancer (PCa).

METHOD: All analyzed patients underwent GSU, CDU/PDU, TRTE and CEUS examinations before radical prostatectomy. Receiver Operating Characteristic (ROC) curves were drawn, and the Areas Under the Curve (AUCs) were calculated for the four ultrasonic modalities alone and in combination. Binary logistic analysis was used to evaluate the predictive value of lesion features observed with the 4 modalities.

RESULTS

The results of the chi-square test showed that the sensitivity, specificity, positive predictive value, negative predictive value, and accuracy rate of TRTE for diagnosing PCa were higher than those of CEUS (p-values were < 0.05 for all). The ROC curves analysis showed that the diagnostic performance of TRTE for PCa was better than that of CEUS (p = 0.046). Moreover, the diagnostic performance of the combination of four ultrasonic technologies (AUC = 0.873) was significantly better than that of any technology alone. Multivariate binary logistic regression analysis showed that enhancement strength on CEUS, presence of a blue area on TRTE and total serum Prostate Specific Antigen (PSA) level were independent predictors for prostate malignancy.

CONCLUSIONS

The diagnostic performance of TRTE was higher than that of CEUS. Early hyperenhancement on CEUS and stiffness on TRTE had high predictive value for the diagnosis of PCa. The combination of multiple ultrasonic modalities can significantly improve the positive diagnostic rate for PCa over that of a single ultrasonic mode.