Contrast-enhanced Transrectal Ultrasonography for Detection and Localization of Prostate Index Tumor: Correlation With Radical Prostatectomy Findings

Abstract

To evaluate the ability of contrast-enhanced transrectal ultrasonography (CETRUS) to detect and localize prostate index tumor. Eighty-three patients with biopsy-proven prostate cancer (PCa), who were scheduled to undergo radical prostatectomy, were enrolled in this prospective study. Each patient underwent baseline grayscale and CETRUS imaging of the prostate according to a standardized protocol before the operation. Ultrasonography findings (CETRUS and grayscale imaging) were correlated with step-section histopathology. Overall, 53 and 68 tumor foci were detected by grayscale imaging and CETRUS, respectively. The combination of grayscale imaging and CETRUS allowed identification of 89 of the 232 cancer foci (38.4%). The sensitivity of combined imaging was significantly superior to that of grayscale imaging (P<.01) and CETRUS (P<.05). Additionally, the prostate index tumor detection rate by the use of grayscale imaging, CETRUS, and their combination was 42 of 83 (50.6%), 53 of 83 (63.9%), and 67 of 83 (80.7%), respectively. The combined approach performed significantly better than grayscale and CETRUS imaging (P<.001 and P<.05, respectively). The index tumor detection rate of CETRUS was higher than that of grayscale imaging, but no significant difference was found (P>.05). Our study has demonstrated significantly improved detection of both PCa and index tumor with a combined approach of CETRUS and grayscale imaging compared with baseline grayscale technique only, and this technique may be applicable to focal therapy of PCa.