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 3cm 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.

Keywords: Malignancy, Liver, Microwave, Surgery