MRI-guided microwave ablation of hepatic malignancies: 4-year institutional outcomes

PURPOSE: We assessed the safety and efficacy of magnetic resonance (MR)-guided microwave ablation for treating hepatic malignancies. METHODS: This retrospective single-center review evaluated patients who underwent MR-guided microwave ablation for hepatic malignancies between 02/15/2017-04/22/2020. Complications were classified following CIRSE guidelines. Local tumor progression (LTP), local tumor recurrence (LTR), non-target progression (NTP), progression-free survival (PFS) and time to progression (TTP) were assessed, with data presented as mean ± standard deviation. RESULTS: Sixteen patients (60.75 ± 14.4 years; 9 males, 7 females) underwent 17 MR-guided microwave ablation for 21 hepatic malignancies (17 (81.0%) hepatocellular carcinoma, 1 (4.8%) cholangiocarcinoma, 2 (9.5%) metastases, and 1 (4.8%) suspicious lesion in a patient with primary sclerosing cholangitis). Lesion size was 12.2 ± 4.8 mm and total procedure time 138 ± 53 minutes. Complications included fever (N = 2), abdominal pain (N = 2), biloma (N = 1), and reactive cholecystitis (N = 1). These resolved with pain medication for one patient and antibiotics for another. No tumor recurrence was observed at ablation sites (LTP and LTR = 0%) at 36.7 ± 28.2 months. NTP occurred in 11 patients (68.8%) with a TTP of 14.8 ± 11.4 months. PFS was 44 months (95% CI: 10-85 months). Three patients died during follow-up - one from complications after liver transplantation and two from disease progression. Post-ablation liver transplantation was performed in two patients. CONCLUSION: MR-guided microwave ablation for hepatic malignancies is safe and effective, with no local tumor recurrences noted over a follow-up period of 36.7 ± 28.2 months. CLINICAL SIGNIFICANCE: MR-guided microwave ablation is a promising minimally invasive treatment for hepatic malignancies, demonstrating no LTR at 36.7 ± 28.2 months. Precise, radiation-free needle placement in real-time and effective targeting of small tumors may further improve future patient care.