Ethan Joseph Halpern MD, Presenter: Grant, Bristol-Myers Squibb Company Equipment support, Toshiba Corporation

Flemming Forsberg PhD, Abstract Co-Author: Support, Regeneron Pharmaceuticals, Inc

Robert Linden MD, Abstract Co-Author: Nothing to Disclose

Paul R. Gittens MD, Abstract Co-Author: Nothing to Disclose

Edouard Trabulsi, Abstract Co-Author: Nothing to Disclose

Leonard G. Gomella MD, Abstract Co-Author: Nothing to Disclose

To evaluate prostate cancer detection with targeted biopsy using MicroFlow Imaging (MFI) as compared to conventional systematic biopsy.

Sixty patients referred for prostate biopsy were evaluated by transrectal US using the PVT-661VT end-fire endocavitary probe with the Aplio scanner (Toshiba America Medical Systems). The microbubble agent Definity (Bristol-Myers Squibb) was diluted into 50 mL of normal saline (concentration = 49.4uL/mL) and infused at a rate of 4 mL/min. MFI is a flash-replenishment technique that uses high power flash pulses to destroy bubbles, followed by low power pulses to demonstrate contrast replenishment. A composite image depicting vascular architecture is constructed through maximum intensity capture of temporal data in consecutive low power images. Up to 5 targeted biopsy cores were obtained from areas of abnormal vascular enhancement or morphology, followed by a systematic 10 core biopsy protocol.

Enhancement of capsular and intraprostatic vessels was observed in all patients. A positive biopsy for cancer was found in 79 cores from 18/60 (30%) of subjects. Positive biopsies were obtained in 50/600 (8.3%) of systematic cores and 29/225 (12.9%) of targeted cores (OR=2.01, p=0.034). Among 18 patients with cancer 2 were identified only by targeted biopsy with MFI, 5 were identified only by systematic biopsy and 11 were identified by both techniques (p>0.25). Cancer detection rate (per patient) as a function of the number of biopsy cores was 0.058 for targeted cores and 0.027 for systematic cores. The vascular pattern observed at positive biopsy sites frequently demonstrated increased vessel size, number and tortuosity.

Contrast-enhanced MFI provides a clear depiction of vascular flow patterns within the prostate. The vascular detail demonstrated with MFI is well suited for identification of suspicious areas for targeted biopsy. Although a minority of cancers are not detected with MFI targeted biopsy, the targeted biopsy technique detected more than twice as many positive patients per biopsy core.

Contrast-enhanced imaging of the prostate with MFI can facilitate targeted biopsy of regions with increased or abnormal vascular morphology.

Halpern, E, Forsberg, F, Linden, R, Gittens, P, Trabulsi, E, Gomella, L, Tarageted Biopsy of Prostate Cancer with Contrast-enhanced Microflow Imaging.  Radiological Society of North America 2007 Scientific Assembly and Annual Meeting, November 25 - November 30, 2007 ,Chicago IL. http://archive.rsna.org/2007/5000522.html