Effects of Liver Tumor and Post-Ablation Necrosis Volume on the Result of Radiofrequency Ablation

Background/Aims: To find out whether the total tumor mass and post-ablation necrosis volume influence the disease-free survival of patients following radiofrequency ablation (RFA). Methodology: Fifty nine patients with RFA of primary and secondary tumors were evaluated retrospectively in a four year period. Total liver mass, post-ablation necrosis volume and their ratio were evaluated using computed tomography examination in the relationship with the risk of insufficient tumor ablation and the disease-free patients survival. Results: A complete ablation was performed in 51 patients, non-ablation in 8 (13.6%) patients. Tumor, necrosis volume were 19.2+/-19.5, 58.7+/-44.7mL, respectively. The tumor and necrosis mass ratio was 0.39+/-0.45. The tumor or necroses mass volume or the tumor/necroses mass ratio had no effect on the patients progression-free survival. Patients with a necrosis volume <25mL had a 10-times higher risk of insufficient ablation (OR=9.9; 95% CI=1.9-51.5; p<0.002) and patients with the tumor/necrosis mass ratio >0.4 had a 8-times higher risk of insufficient ablation (OR=7.9; 95% CI=1.4-44.6; p<0.01). Conclusions: Necrosis volume after RFA and tumor/necrosis mass ratio are the important factors for insufficient ablation but do not have any influence on the patients progression-free survival.