Robert Susil, PRESENTER: Nothing to Disclose

Abstract: HTML Purpose: A system for MRI-guided transperineal prostate biopsy and high-dose-rate brachytherapy (HDRT) in a 1.5T closed MR scanner is described. In a series of 6 procedures (in 3 patients), the technique allowed for localized tissue biopsy and brachytherapy catheter placement with an accuracy of <5 mm. Methods and Materials: An MR compatible system, including a positioning arm (Siemens Medical Systems, Erlanger, Germany), an intrarectal imaging coil (USA Instruments, Aurora, OH), and a custom-built perineal template, was designed for transperineal needle insertion under MR guidance. The patient, under general anesthesia, was placed in the left lateral decubitus position to maximize perineal exposure in the closed bore magnet. SSFP and T1 weighted images were used for online planning and placement of biopsy needles and brachytherapy catheters. T2 weighted axial MR images of the prostate and surrounding tissues were used for 3D optimization of HDRT dose delivery (PLATO, Nucletron, Columbia MD). Results: In each of the six procedures, an average of 3 core biopsies were collected and 14 brachytherapy catheters were inserted. Needle placement accuracy over all procedures was less than 5 mm. All patients tolerated the procedure very well and no unexpected adverse events were experienced. Overall procedure times and dosimetric parameters have both significantly improved through this series of procedures. MRI time is less than 2 hours, and the overall procedure can be completed in less than 5 hours. Target V100 (% of target receiving >100% of prescribed dose) is now consistently greater than 90% while respecting urethral dose tolerance (urethral V125 < 5%). Conclusion: While HDRT treatment planning and tissue biopsy were preformed using SSFP, T1, and T2 weighted images of the prostate (i.e. anatomical imaging), the platform allows for the use of functional imaging techniques (such as MR spectroscopy and dynamic contrast enhancement) to aid in tumor mapping and target delineation. By simultaneously delivering diagnostic quality 1.5 T MR images and transperineal needle access to the prostate, this platform can improve the accuracy of both prostate cancer diagnosis and minimally invasive therapeutics. (R.S. has an affiliation with Nucletron, Inc.)       Questions about this event email: rcs@jhu.edu

Susil, R, A System for Transperineal Prostate Biopsy and HDR Brachytherapy under 1.5 T MRI Guidance: Techniques and Clinical Experience.  Radiological Society of North America 2003 Scientific Assembly and Annual Meeting, November 30 - December 5, 2003 ,Chicago IL. http://archive.rsna.org/2003/3108235.html