High technical success rate for liver needle placement with the CT-guide navigation system

Purpose To evaluate the efficacy of using the ActiViews CT-Guide® navigation system in the accurate placement of needles in liver biopsy and liver ablation. The system allows registration of a CT data set to an optical navigation system allowing free-hand needle placement using a virtual image analogous to CT fluoro. The system easily allows needle placement in off-axial trajectories. Materials and Methods Cohort study of twenty sequential patients undergoing CT guided hepatic needle placement, for either biopsy or thermal ablation, were enrolled in this study. IRB approved. Informed consent. Demographics were captured. Adequacy of needle tip placement was measured. Target parameters such as lesion size and depth from skin were noted. Total navigation time, number of scans performed and radiation dose were noted. Device related adverse events were monitored. All procedures were performed by experienced radiologists. Results Of the 20 patients, there were 7 females/13 males. Average age was 63 (range 43-80 years). All twenty needle placement procedures were technically successful. Average lesion size was 3.3 cm, 3.6 cm for the 14 biopsies biopsies and 1.8cm for the 6 ablations. Lesion depth was 8.1cm on average, 7.2 cm for biopsies and 9.7 cm for ablations. Navigation time was 3.9 minutes on average; 3.3 minutes for biopsies and 5.3 minutes for ablations. Radiation dose, measured as Dose Linear Product, DLP, was 1779 for all, 1675 for biopsies, and 2010 for ablations. There were no device related adverse events in the study group. Conclusion The CT-Guide® navigation system (ActiViews Inc., Wakefield, MA) has proven to be safe and effective in assisting in CT guided needle navigation. Our technical success rate was 100%. The system is easy-to-use after a short learning curve and proved especially useful in situations where lesions are only transiently visible on arterial phase, and in cases requiring multiple ablations. At our institution it has become standard to use this device for almost all ablations and most challenging biopsies.