Trans-urethral ultrasound imaging of the prostate for applications in prostate brachytherapy: Analysis of phantom and in vivo data

3D Trans-Urethral Ultrasound (TUUS) imaging is a new imaging technique for the diagnosis and treatment of prostate disease. Our current research focuses on the potential of TUUS in therapy guidance during transperineal interstitial permanent prostate brachytherapy (TIPPB). TUUS may complement or potentially replace x-ray fluoroscopy and TRUS in providing data for determining the prostate boundary and radiation source locations. Prostate boundary detection and source localization using TUUS were tested on an ultrasound-equivalent prostate phantom and in a patient during TIPPB. Data collection was conducted with a 10 French, 10 MHz ultrasound catheter controlled by an Acuson Sequoia™ workstation. 2D and 3D TUUS scans were acquired after radioactive seeds were placed in the phantom and in the patient. Data was reconstructed, processed, and analyzed using Analyze software. Segmentation of the prostate boundary was performed semi-automatically, and seed segmentation was performed manually. Image artifacts in TUUS data resulted in incorrect reconstruction of the seeds. Intelligent processing of the seed data improved reconstruction. Comparison to the CT data suggests that TUUS data provides: 1) greater spatial resolution, 2) greater temporal resolution and 3) better contrast for soft tissue differentiation. The reconstructed source sizes and locations were measured and found accurate. Placement of the TUUS catheter into the urethra provides excellent 2D sections which can be used to acquire volumetric data for 3D analysis of the prostate and radioactive sources. Preliminary results suggest that TUUS will be useful for guidance of seed placement, post-implant seed localization, and intra-operative dosimetry.