Fiducial marker-assisted microwave ablation of hepatocellular carcinoma: achieving margins without contrast

Abstract Purpose To evaluate the technique of fiducial marker placement to guide cone-beam computed tomography (CBCT) trajectory planning and ablation predictive software for ablation of a segment IVB, biopsy-confirmed, 4.5 × 4.2 × 3.4 cm hepatocellular carcinoma in a patient refusing contrast administration. Methods Utilizing ultrasound guidance and fluoroscopic confirmation, six coils were placed at the anatomic margins of the lesion. Following placement, a microwave antenna was advanced under ultrasound and CBCT guidance to abut the first fiducial marker. CBCT was then performed to confirm suitable positioning. Ablation predictive software was utilized to determine the maximal, yet safe, ablation zone for the probe position. This process was repeated at each fiducial marker to encompass the entire lesion with appropriate margins. Results The total fluoroscopic time was 18.5 min; the cumulative dose was 1405 mGy. There were no intraoperative or immediate complications. The patient experienced mild post-ablation epigastric pain for 1 week following the procedure. At 1-month follow-up, the patient had no complaints. The initial post-procedure MRI, and now the most recent 26-month follow-up MRI, demonstrates complete response of the target lesion by mRECIST criteria. Conclusion Ultrasound-guided fiducial marker placement for guidance of cone-beam CT trajectory planning combined with ablation predictive software is a viable technique for ablation of > 3-cm hepatocellular carcinoma when contrast is contraindicated. Future prospective studies are indicated to further evaluate this approach.