First clinical use of the EchoTrack guidance approach for radiofrequency ablation of thyroid gland nodules

  • Alfred Michael Franz
  • Alexander Seitel
  • Nasrin Bopp
  • Christian Erbelding
  • Dominique Cheray
  • Stefan Delorme
  • Frank Grünwald
  • Hüdayi Korkusuz
  • Lena Maier-Hein
Original Article



Percutaneous radiofrequency ablation (RFA) of thyroid nodules is an alternative to surgical resection that offers the benefits of minimal scars for the patient, lower complication rates, and shorter treatment times. Ultrasound (US) is the preferred modality for guiding these procedures. The needle is usually kept within the US scanning plane to ensure needle visibility. However, this restricts flexibility in both transducer and needle movement and renders the procedure difficult, especially for inexperienced users. Existing navigation solutions often involve electromagnetic (EM) tracking, which requires placement of an external field generator (FG) in close proximity of the intervention site in order to avoid distortion of the EM field. This complicates the clinical workflow as placing the FG while ensuring that it neither restricts the physician’s workspace nor affects tracking accuracy is awkward and time-consuming.


The EchoTrack concept overcomes these issues by combining the US probe and the EM FG in one modality, simultaneously providing both real-time US and tracking data without requiring the placement of an external FG for tracking. We propose a system and workflow to use EchoTrack for RFA of thyroid nodules.


According to our results, the overall error of the EchoTrack system resulting from errors related to tracking and calibration is below 2 mm. Navigated thyroid RFA with the proposed concept is clinically feasible. Motion of internal critical structures relative to external markers can be up to several millimeters in extreme cases.


The EchoTrack concept with its simple setup, flexibility, improved needle visualization, and additional guidance information has high potential to be clinically used for thyroid RFA.


Ultrasound guidance Electromagnetic tracking Computer-assisted interventions Thyroid radiofrequency ablation 



This work was supported by the European Union through the ERC starting Grant COMBIOSCOPY under the New Horizon Framework Programme Grant Agreement ERC-2015-StG-37960. We further thank Jennifer Mosebach for helping with measuring the volume of the thyroid lobes of our volunteers.

Compliance with ethical standards

Conflict of interest

The authors declare that they have no conflict of interest.

Ethical approval

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 amendments or comparable ethical standards.

Informed consent

Informed consent was obtained from all individual participants in the study.


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Copyright information

© CARS 2017

Authors and Affiliations

  • Alfred Michael Franz
    • 1
  • Alexander Seitel
    • 1
  • Nasrin Bopp
    • 1
  • Christian Erbelding
    • 2
  • Dominique Cheray
    • 1
  • Stefan Delorme
    • 3
  • Frank Grünwald
    • 2
  • Hüdayi Korkusuz
    • 2
  • Lena Maier-Hein
    • 1
  1. 1.Division of Computer Assisted Medical InterventionsGerman Cancer Research Center (DKFZ)HeidelbergGermany
  2. 2.Department of Nuclear MedicineUniversity Hospital FrankfurtFrankfurtGermany
  3. 3.Division of RadiologyGerman Cancer Research Center (DKFZ)HeidelbergGermany

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