Liver-directed therapy for hepatic metastases includes: intra-arterial techniques such as trans-arterial chemoembolization (TACE) and yttrium-90 resin (90Y) microsphere radioembolization and ablative technologies: cryoablation, radiofrequency ablation, and microwave ablation. Combining embolization techniques with liver ablation may enhance the therapeutic benefit of each and result in improved patient survival. We retrospectively reviewed our experience with combined intra-arterial therapies and ablation for unresectable hepatic colorectal metastases from 1996 to 2011. Patient demographics, tumor characteristics, specific liver-directed treatments, procedure-related morbidity and mortality, and overall survival were recorded. There were 17 (53%) males and 15 (47%) females. Average age for the group was 74.1 years (median, 75.5 years). Fifteen patients (46.9%) had a single hepatic metastasis. Eleven (34%) patients had bilobar tumor distribution and seven (22%) patients had vascular invasion of the portal vein or hepatic/caval venous structures. Seven (21%) tumors were greater than 5 cm in diameter. Twenty-seven (84.4%) patients received TACE and five (15.6%) received 90Y. Fourteen (43%) were embolized before any ablation. Fifty-three per cent of patients required multiple hepatic ablation sessions. Median length of hospital stay was 1 day. There were no procedure-related mortalities and complications occurred in six (18.8%) patients. Mean follow-up for the group was 33 months. Kaplan-Meier 1-, 3-, and 5-year estimated survival was 93.8, 50.0, and 10.1 per cent, respectively. Median survival for the group was 46 months. Hepatic ablation and embolization techniques can be combined safely with minimal morbidity. In our series, we observed 5-year survival in 10 per cent of patients.
Antenna design for microwave hepatic ablation using an axisymmetric electromagnetic model
