C-Arm Cone-Beam CT Combined with a New Electromagnetic Navigation System for Guidance of Percutaneous Needle Biopsies: Initial Clinical Experience

Abstract

Purpose: To evaluate the feasibility and efficacy of C-arm fluoroscopic cone-beam computed tomography (CACT) in combination with a new electromagnetic tracking (EMT) system for needle guidance during percutaneous biopsies.

Materials and methods: 53 patients were referred for biopsy of thoracic (n = 19) and abdominal (n = 34) lesions. CT-like images of the anatomical region of interest (ROI) were generated using a flat panel-based angiographic system. These images were transmitted to an EMT system. A coaxial puncture needle with a sensor in its tip was connected with the navigation system and tracked into an electromagnetic field created via a field generator. Data generated within this field were merged with the CACT images. On a monitor both the anatomical ROI and needle tip position were displayed to enable precise needle insertion into the target. Through the coaxial needle, biopsy specimens for the histologic evaluation were extracted. Number of representative biopsy samples, number of core biopsies/patient, total procedure time, dose-area product, fluoroscopic time, and complications were recorded.

Results: 53 CACT/EMT-guided biopsy procedures were performed, 48 of which (91 %) yielded representative tissue samples. Four core biopsies were obtained from each patient. 40 (75 %) lesions were malignant and 13 (25 %) lesions were benign. The total procedure time was 9 ± 5 min (range, 3 - 23 min), fluoroscopic time was 0.8 ± 0.4 min (range, 0.4 - 2 min). The mean dose-area product (cGy cm²) was 7373 (range, 895 - 26 904). The rate of complications (1 pneumothorax, 2 hemoptyses) was 6 %.

Conclusion: CACT combined with EMT appears to be a feasible and effective technique for the guidance of percutaneous biopsies with a low rate of therapeutically relevant complications.

Key points: • Guidance of percutaneous biopsies with a combination of CACT and EMT is technically feasible. • CACT/EMT-guided biopsies are associated with a good diagnostic yield. • The rate of complications appears to be low for this guidance technique.