134 - Electromagnetic Navigation with Marker Guidance for Microwave Ablation of CT-Inconspicuous Liver Lesions: Prospective Feasibility and Outcomes Study

Monday, April 13, 2026

3:45 PM - 3:54 PM ET

Presenting Author(s)

Ornella Moschovaki-Zeiger, MD

INTERVENTIONAL RADIOLOGY TRAINEE
"ATTIKON" UNIVERSITY GENERAL HOSPITAL, Greece

Author/Co-author(s)

Vasileios Balomenos, MD

Radiology Resident
Attikon University General Hospital, Greece
MP

Myrto Papadopoulou, MD

Radiology Resident
Radiology Department, Evangelismos General Hospital, Greece
David-Dimitris Chlorogiannis, MD

Research Scholar
Brigham and Women's Hospital, Harvard Medical School, United States
AG

Athanasios Giannakis, MD

Radiology Consultant
2nd Department of Radiology, University General Hospital "ATTIKON", Medical School, National and Kapodistrian University of Athens, Greece
NK

Nikolaos Kelekis, MD

PROFESSOR OF RADIOLOGY, Greece
Dimitrios Filippiadis, MD, PhD (he/him/his)

Professor of Interventional Radiology
2nd Department of Radiology, University General Hospital "ATTIKON" Medical School, National and Kapodistrian University of Athens, Greece

Purpose: To evaluate the feasibility, safety, and efficacy of percutaneous microwave ablation (MWA) of malignant liver lesions that are invisible or poorly defined on non-contrast CT, using an electromagnetic navigation system with a marker function.

Materials and Methods: In this prospective study (March 2024–March 2025), all patients with hepatic tumors being inconspicuous on non-enhanced CT underwent percutaneous MWA guided by electromagnetic navigation with a marker function in combination with computed tomography. Technical success was confirmed with immediate post-ablation contrast-enhanced CT. Follow-up MRI was performed at 1, 3, and 6 months to assess local tumor control. Outcomes included probe placement accuracy, procedure duration, number of CT scans, and complications per modified CIRSE classification.

Results: Fifteen patients (12 men, mean age 66 years) with 16 lesions (mean diameter 15 mm) were treated. Lesion types included HCC (n=7), colorectal metastases (n=4), ocular melanoma (n=1), neuroendocrine tumor (n=1), intrahepatic cholangiocarcinoma (n=1), and breast cancer metastasis (n=1). Median procedure time was 53 minutes, with a median 1 mm needle placement deviation. No complications occurred. Local control was 94% after a single session and 100% after re-ablation, with no local progression during a median follow-up of 23 months. Three patients (20%) experienced systemic progression; two died (13%), one cancer-related.

Conclusion: Electromagnetic navigation with marker guidance enables highly accurate and safe MWA of CT-inconspicuous hepatic tumors, offering excellent local control and favorable long-term oncologic outcomes.