67th Annual Meeting Abstracts

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Flash Replenishment Imaging with Contrast-enhanced Ultrasound Identifies High Volume / High Grade Prostate Cancer
Steve Dong, *Ethan Halpern, *Flemming Forsberg, Leonard Gomella, Edouard Trabulsi
Thomas Jefferson University, Philadelphia, PA

Introduction: To evaluate the detection of prostate cancer using contrast-enhanced ultrasound with an advanced flash replenishment technique - MicroFlow Imaging (MFI).
Materials & Methods: 136 patients referred for prostate biopsy were evaluated by transrectal US. The microbubble agent Definity (Bristol-Myers Squibb) was diluted into concentration of 49.4uL/mL and infused at a rate of 4 mL/min. MFI uses high power flash pulses to destroy bubbles, followed by low power pulses to demonstrate contrast replenishment and depict vascular architecture. Up to 6 targeted biopsy cores were obtained from areas of abnormal vascular enhancement or morphology on MFI, followed by a systematic 12 core biopsy protocol.
Results: Enhancement of capsular and intraprostatic vessels was observed in all patients. Positive biopsies were obtained in 137/1632 (8.4%) of systematic cores and 93/555 (16.8%) of targeted cores (OR=3.3, p<0.001). Among the 49 patients detected by systematic biopsy, those 30 patients with a positive targeted core demonstrated an average of 3.7 positive systematic cores while those 19 patients who were missed by targeted biopsy demonstrated an average of 1.5 positive systematic cores (p=0.001). Mean percentage of systematic biopsy core involvement was 32% among patients with a positive targeted core, compared with 15% among patients who were missed by targeted biopsy (p=0.01). Higher grade cancer (Gleason score >6) was more common among patients with a positive targeted biopsy (47% versus 16%; p=0.03).
Conclusions: Targeted biopsy of the prostate using contrast-enhanced MFI imaging of the prostate identifies high volume/grade cancers which are most likely to be clinically significant.

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