Magnetic resonance-guided thermal ablation for small liver malignant tumor located on segment II or IVa abutting the heart: a retrospective cohort study.

Objective: This study aimed to evaluate the clinical safety and efficacy magnetic resonance (MR)-guided percutaneous thermal ablation for the treatment of small liver malignant tumors of segment II and IVa (≤3.0 cm) abutting the heart.

Method: The enrollment of 24 patients with 25 malignant liver lesions located on the II or IVa segment abutting the heart who underwent MRI-guided thermal ablation between August 2010 and February 2020 were retrospectively analyzed. Follow-up MRI was performed to evaluate the curative effect. Local tumor progression-free survival and overall survival rates were also calculated.

Results: The procedures including radiofrequency ablation (RFA) for 15 patients and microwave ablation (MWA) for 9 patients were successfully accomplished (technical success rate of 100%) without major complications. The mean duration time was 78.4 ± 29.4 min (40-140 min), and mean follow-up time was 31.5 ± 22.2 months (6-92 months). The technical efficacy was 100% following one ablation session with MRI assessment after one month. Local tumor progression was observed in one patient with a metastatic lesion located in segment II at 18 months follow-up. The progression-free survival time was 20.1 ± 16.9 months (median: 15 months). The 1-, 3-, and 5-year local tumor progression-free survival rates of this patient were 100%, 94.7%, and 94.7%, respectively. With regards to all the patients, the 1-, 3-, and 5-year estimated overall survival rates were 91.7%, 80.6%, and 50.1%, respectively.

Conclusion: MR-guided thermal ablation is safe and effective for the treatment of small liver malignant tumors located on the II or IVa segment abutting the heart.