Contrast Enhanced Transrectal Ultrasound for the Detection of Prostate Cancer: A Randomized, Double-Blind Trial of Dutasteride Pretreatment

Abstract

The identification of clinically significant disease is crucial for optimal treatment of prostate cancer. Selective detection of prostate cancer with increased microvessel density is possible with contrast enhanced ultrasound. Preliminary studies suggest that pretreatment with a 5α-reductase inhibitor may improve the efficiency of contrast enhanced ultrasound targeted biopsy. This study was designed to quantify prostate cancer detection with contrast enhanced ultrasound with or without short-term pretreatment with dutasteride. In this randomized, double-blind, placebo controlled trial of oral dutasteride pretreatment, contrast enhanced ultrasound findings were graded and used to direct targeted biopsy (up to 6 cores per prostate). A blinded 12-core systematic biopsy was subsequently performed on every subject based on standard medial and lateral sampling of each sextant. Of 311 subjects who underwent randomization, 272 completed participation. Positive biopsies were obtained in 276 of 3,264 (8.5%) systematic cores and 203 of 1,237 (16.4%) targeted cores (OR 2.1, 95% CI 1.7-2.6, p <0.001). ROC analysis for the detection of all prostate cancers demonstrated an increase in diagnostic accuracy from pre-contrast imaging to contrast enhanced ultrasound (A(z) 0.60 vs 0.64, p = 0.005). For the detection of high grade cancer (Gleason score 7 or greater) ROC analysis demonstrated improved accuracy for pre-contrast imaging (A(z) 0.74) and contrast enhanced ultrasound (A(z) 0.80, p = 0.0005). For the detection of high grade cancer with greater than 50% biopsy core involvement, excellent accuracy was demonstrated with pre-contrast and contrast enhanced ultrasound, A(z) 0.83 and 0.90, respectively (p = 0.001). Pretreatment with dutasteride had no significant impact on the detection of prostate cancer (p = 0.97). Contrast enhanced ultrasound targeted biopsy provides a significant benefit for the detection of high grade/high volume prostate cancer.