Prostate cancer is the most common male cancer in the United States, and the third most common worldwide. Prostate biopsies are often performed to confirm a cancer diagnosis and examine suspect tissue. Prostate biopsies are most often performed under transrectal ultrasound imaging (TRUS) guidance. TRUS images in real-time, at relatively low cost, and shows both prostate and boundaries. However, major problems with TRUS imaging are poor spatial resolution and low sensitivity for cancer detection. Fusion of TRUS images with preoperative images such as Magnetic Resonance (MR) or CAT may improve accuracy and resolution. But, this approach still requires TRUS imaging during the procedure and negates some of the relatively low cost. In addition, fusion of TRUS and MR images requires sensors such as electromagnetic (EM) tracking to determine position and orientation. This increases the expense and complicates the process. The TRUS imaging process itself is invasive, stressful to patients, and increases infection risk.
Researchers at Clinical Center (CC) developed a system that enables less-invasive prostate biopsies without the need for a tracking sensor. This is done through elimination of the TRUS probe in favor of a 3D ultrasound probe and custom image pre-registration to preoperative high-resolution volume scan (such as MR or CAT). The use of the 3-D probe allows for ultrasound image acquisition via perineal placement. The ultrasound images are registered to a biopsy needle guidance grid. To improve accuracy, the image registration to the grid trajectories is fused with grid registration images from preoperative MR or CAT images. The specific apertures in the needle guidance grid is selected based on the optimal trajectories to target tissue area for biopsy. This system offers a simpler, more accurate, less invasive and less expensive procedure than traditional TRUS-guided fusion biopsy.