The Efficacy of Electromagnetic Navigation to Assist with Computed Tomography–Guided Percutaneous Thermal Ablation of Lung Tumors

Abstract

Electromagnetic (EM) navigation is increasingly used to assist with bronchoscopic interventions such as biopsy or fiducial placement. Electromagnetic navigation can also be a useful adjunct to computed tomography (CT)-guided thermal ablation and biopsy of lung tumors. This study compares procedures carried out using an EM navigation system (Veran Medical Technologies Inc, St Louis, MO) with procedures using CT fluoroscopy only. Over a 23-month period, 17 patients scheduled for thermal ablation were prospectively enrolled in this study. The mean age was 72 years (range, 60-84 years). Seven patients were women. Patients were randomized to EM navigation (n = 7) or CT fluoroscopy alone (n = 10). In some cases, additional ablation or biopsies were performed with or without EM navigation depending on the randomization arm. All procedures were performed under general anesthesia either by a thoracic surgeon or a radiologist. A total of 23 procedures were performed in 17 patients: 20 were ablation procedures and 3 were biopsies. Fourteen were performed for non-small cell lung cancer, and 9 for pulmonary metastases from other organs. Despite randomization, patients receiving EM navigation had a trend for smaller tumors (mean diameter, 1.45 vs 2.90 cm; P = 0.06). For thermal ablation procedures, the time to complete intervention was significantly less when EM navigation was used (mean, 7.6 vs 19 minutes; P = 0.022). Although not statistically significant, there were fewer skin punctures (mean, 1 vs 1.25; P = 0.082), fewer adjustments (mean, 5.6 vs 11.8; P = 0.203), less CT fluoroscopy time (mean, 21.3 vs 34.3 seconds; P = 0.345), and fewer CT scans (mean, 7 vs 15; P = 0.204) whenever EM navigation was used. Electromagnetic navigation reduces the time to successfully place an ablation probe in a target tumor. Further study is required to determine whether EM navigation may also reduce the number of adjustments, skin punctures, and CT scans as well as decrease CT fluoroscopy time.