CT-guided liver biopsy with electromagnetic tracking: results from a single-center prospective randomized controlled trial

OBJECTIVE. The purpose of this study is to evaluate the effectiveness of electromagnetic tracking in assisting CT-guided liver biopsies. MATERIALS AND METHODS. This was a single-center prospective randomized controlled trial comparing nonfluoroscopic CT-guided liver biopsy using an advance-andscan technique with and without electromagnetic tracking. Fifty patients with a liver lesion referred for biopsy (women, 52%; mean age, 59.7 years; mean lesion size, 3.6 cm) were enrolled in the study and were randomly assigned to either arm. The primary and secondary objectives were to assess and quantify differences in the number of intraprocedural scans, cumulative effective radiation dose, number of needle manipulations, and procedure time from skin-stick to the target lesion with and without assistance. RESULTS. Electromagnetic tracking significantly decreased the number of scans, effective radiation dose, number of manipulations per procedure, and time from skin-stick to the target lesion. The ratio of the number of scans (electromagnetic tracking to control) was 0.55 (95% CI, 0.42-0.73; p <0.0001). The mean difference in effective radiation dose (electromagnetic tracking-control) was -4.7 mSv (95% CI, -7.01 to -2.44 mSv; p = 0.0001), and the median difference was -5.1 mSv (95% CI, -7.01 to -3.56 mSv; p <0.0001). The ratio of the number of manipulations (electromagnetic tracking to control) was 0.36 (95% CI, 0.24-0.54; p <0.0001). The mean difference for the time from skin-stick to the target lesion was -247.6 seconds (95% CI, -394.34 to -100.83 seconds; p = 0.0014) and the median difference was -253.0 seconds (95% CI, -325.00 to -124.00 seconds; p = 0.0001). CONCLUSION. Electromagnetic tracking assistance has the potential to decrease the number of intraprocedural CT scans and needle manipulations and to reduce patient radiation dose during CT-guided liver biopsy.