Results of single-probe microwave ablation of metastatic liver cancer

Abstract

Aims: Microwave ablation (MWA) is the most recent development in the field of local ablative therapies. The aim of this study was to evaluate the variability and reproducibility of single-probe MWA vs. radiofrequency ablation (RFA) of liver metastases smaller than 3 cm in patients without underlying liver disease. Methods: Sixteen liver metastases were treated using MWA, and matched for size and localisation with 13 metastases treated by RFA. Tumour diameters and postoperative ablation diameters were recorded (D1 transverse; D2 antero-posterior; D3 cranio-caudal; mm) on computed tomography scans. Results: Median D1, D2, and D3 ablation diameters after MWA vs. RFA were 18.5 (12-64) vs. 34 (16-41) mm (p = 0.003), 26 (14-60) vs. 35 (28-40) mm (p = 0.046), and 20 (10-73) vs. 32 (20-45) mm (p = 0.025), respectively. As compared to RFA, the variability between the lesions after MWA was significantly higher for D2 (p < 0.0001) and D3 (p = 0.002) but not for D1 (p = 0.15). The ablation diameters were less uniform after MWA than after RFA (p < 0.001). Conclusion: Ablation diameters after single-probe MWA of metastatic liver tumours are highly variable and suboptimal. Improvements are needed before MWA can be implemented routinely. (C) 2010 Elsevier Ltd. All rights reserved.