Electromagnetic Navigation System-Guided Microwave Ablation of Hepatic Tumors: A Matched Cohort Study



To assess the accuracy and applicability of an electromagnetic navigation system (EMNS) for CT-guided microwave ablation (MWA) of hepatic tumors in comparison with conventional CT-guidance.

Materials and Methods

34 patients (m = 20/f = 14, mean age 34 y) with 34 liver tumors (primary = 22, metastases = 14, mean size 20 mm) referred for CT-guided MWA were included in this IRB-approved study. Interventions were performed prospectively using an EMNS in 17 patients (navigation group), and results were compared to a matched historic cohort of 17 patients using conventional CT-guidance (control group, t-test, p < 0.05 deemed significant). Primary outcome measurement: accuracy of antenna placement (deviation). Secondary outcome measurements: setup time, number of control scans, duration and radiation exposure for antenna placement.


Ablations were performed using a single or a double-angulated approach. Application of the EMNS was feasible in 14 cases (82%). Mean total deviation of the antenna feed point in the navigation and control group was 2.4 mm (range 0.2–4.8 mm) and 3.9 mm (range 0.4–7.8 mm), p < 0.05. Mean setup time for the EMNS was 6.75 ± 3.9 min (range 3–12 min). Mean number of control scans in the navigation and control group was 3 ± 0.9 (range 1–4) and 6 ± 1.3 (range 4–8), p < 0.0001; mean time for antenna placement was 9 ± 7.3 min (range 1.4–25.9 min) and 11.45 ± 6.1 min (range 3.9–27.4 min), p = 0.3164. Radiation exposure was significantly less in the navigation group.


Our experience in a limited number of patients suggests that EMNS enables intuitive CT-guided MWA of liver tumors with higher accuracy when compared to ablations performed without navigation and with fewer control scans needed.

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  1. 1.

    Jones C, Badger SA, Ellis G. The role of microwave ablation in the management of hepatic colorectal metastases. Surgeon. 2011;9:33–7.

    CAS  Article  Google Scholar 

  2. 2.

    European Association For The Study Of The Liver. EASL-EORTC clinical practice guidelines: management of hepatocellular carcinoma. J Hepatol. 2012;56:908–43.

    Article  Google Scholar 

  3. 3.

    Ahmed M, Solbiati L, Brace CL, et al. Image-guided tumor ablation: standardization of terminology and reporting criteria—a 10-year update. J Vasc Interv Radiol. 2014;25(1691–705):e1694.

    Google Scholar 

  4. 4.

    Vo Chieu VD, Werncke T, Hensen B, Wacker F. Ringe KI CT-guided microwave ablation of liver tumors in anatomically challenging locations. Cardiovasc Intervent Radiol. 2018;41:1520–9.

    Article  Google Scholar 

  5. 5.

    Moncharmont L, Moreau-Gaudry A, Medici M, Bricault I. Phantom evaluation of a navigation system for out-of-plane CT-guided puncture. Diagn Interv Imaging. 2015;96:531–6.

    CAS  Article  Google Scholar 

  6. 6.

    Durand P, Moreau-Gaudry A, Silvent AS, et al. Computer assisted electromagnetic navigation improves accuracy in computed tomography guided interventions: a prospective randomized clinical trial. PLoS ONE. 2017;12:e0173751.

    Article  Google Scholar 

  7. 7.

    Filippiadis DK, Binkert C, Pellerin O, Hoffmann RT, Krajina A, Pereira PL. Cirse quality assurance document and standards for classification of complications: the cirse classification system. Cardiovasc Interv Radiol. 2017;40:1141–6.

    CAS  Article  Google Scholar 

  8. 8.

    Moulin B, Tselikas L, De Baere T, et al. CT guidance assisted by electromagnetic navigation system for percutaneous fixation by internal cemented screws (FICS). Eur Radiol. 2020;30:943–9.

    Article  Google Scholar 

  9. 9.

    Teriitehau C, Rabeh H, Pessis E, Sénéchal Q, Besse F, Bravetti M. Reduction of patient radiation dose during percutaneous CT vertebroplasty: impact of a new computer-assisted navigation (CAN) system. Radioprotection. 2020;55:11–6.

    CAS  Article  Google Scholar 

  10. 10.

    Jiang C, Liu B, Chen S, Peng Z, Xie X, Kuang M. Safety margin after radiofrequency ablation of hepatocellular carcinoma: precise assessment with a three-dimensional reconstruction technique using CT imaging. Int J Hyperthermia. 2018;34:1135–41.

    CAS  Article  Google Scholar 

  11. 11.

    Zhang Z, Shao G, Zheng J, et al. Electromagnetic navigation to assist with computed tomography-guided thermal ablation of liver tumors. Minim Invasive Ther Allied Technol. 2019;8:1–8.

    Article  Google Scholar 

  12. 12.

    Volpi S, Tsoumakidou G, Loriaud A, Hocquelet A, Duran R, Denys A. Electromagnetic navigation system combined with high-frequency-jet-ventilation for CT-guided hepatic ablation of small US-undetectable and difficult to access lesions. Int J Hyperth. 2019;36:1051–7.

    Article  Google Scholar 

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This study was not supported by any funding.

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Corresponding author

Correspondence to K. I. Ringe.

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Conflict of interest

Hatem Rabeh is employed by IMACTIS. All other authors declare that they have no conflict of interest.

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All procedures performed in studies involving human participants were in accordance with the ethical standards of the institutional and/or national research committee and with the 1964 Helsinki Declaration and its later amendment or comparable ethical standards.

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This study has obtained IRB approval from Hannover Medical School and the need for informed consent was waived.

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Consent for publication was obtained for every individual person’s data included in the study.

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Ringe, K.I., Pöhler, G.H., Rabeh, H. et al. Electromagnetic Navigation System-Guided Microwave Ablation of Hepatic Tumors: A Matched Cohort Study. Cardiovasc Intervent Radiol 44, 500–506 (2021). https://doi.org/10.1007/s00270-020-02761-6

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  • Microwave ablation
  • Electromagnetic
  • Navigation
  • Computed tomography
  • Accuracy