Learning curve of microwave ablation for liver cancers

Background Microwave ablation (MWA) has been increasing accepted as a curative therapy in small liver tumors but its learning curve is still unknown. This study aims to evaluate MWA efficacy and safety by cumulative MWA volume and interventional experience. Materials This study included 3113 primary liver cancers treated by MWA by 7 operators. Conditional logistic regression was used to estimate within-operators effects of increasing cumulative MWA volume per year on major complication, technical success (TS) and local tumor progression (LTP) rates were adjusted for treatment-level characteristics. Changes were also evaluated by subgroups of tumor size and tumor location. Results Lower severe complication rate was detected only in higher MWA volume (P = 0.02). Previous interventional experience had no influence on major complication rate. TE rates increased with the increase of MWA volume (all P