To report our early clinical experience using C-arm Cone Beam Computed Tomography (C-arm CBCT) with fluoroscopic overlay for needle guidance during vertebroplasty.
Materials & Methods
Between November 2007 and March 2008, eight consecutive patients underwent vertebroplasty of ten vertebral levels. Target and needle entry points were selected on a C-arm CBCT image to determine a path for the needle. The needle path, target point, and 3D image are inherently registered to live fluoroscopy during the procedure and used to guide needle placement. The target point for each procedure was chosen to be at the midline of the anterior 1/3 of the vertebral body. We retrospectively reviewed the medical records and pertinent imaging studies. Procedural data including vertebral level, approach (transpedicular vs. extrapedicular), access (bilateral vs. unilateral) and complications were recorded. Success with the overlay technology was assessed based on accuracy which was defined as distance from planned path to final needle tip within 5 mm and distance from midline to final needle tip within 5 mm on multiplanar CBCT or fluoroscopy.
Results
Imaging data for 9 vertebral levels was available for review. Technical success for needle accuracy was achieved in all levels (100%) with a mean of 3.38mm from final needle tip position to planned path and a mean of 1.4 mm from final needle tip position to midline. The involved levels included 5 lumbar and 5 thoracic levels. All vertebrae were treated using unilateral access with all lumbar levels accessed via a transpedicular route and all thoracic levels via an extrapedicular approach. There was one case of cement extravasation into the disc space.
Conclusion
Target path overlay for needle guidance during fluoroscopy guided vertebroplasty is feasible and allows for reliable unilateral therapy of both lumbar and thoracic vertebral bodies.
1University of Texas M.D. Anderson Cancer Center, Houston, TX
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