[Radiofrequency ablation combined with ethanol injection for liver cancer treatment---an experimental study]

Radiofrequency ablation (RFA), which is widely used in treating primary and secondary liver cancer, is regarded as one of the most effective and promising regional therapies to date. However, limited necrosis region and high local recurrence are the major disadvantages of RFA. Researches on RFA are mostly focused on how to widen necrosis regions and decrease local recurrence. This study was to investigate whether RFA combined with ethanol injection (PEI) would widen necrosis region.

Ex-swine and rabbit VX2 liver cancer models were used for in vitro and in vivo experiments, respectively. Four groups of each model were treated with RFA, PEI, RFA-PEI, and PEI-RFA, respectively. The size, shape, and volume of necrosis lesions, parameters (time and power) of RFA, and adverse events in the 4 groups were analyzed.

In in vitro study, compared with those of groups PEI, RFA, and RFA-PEI, the mean size of necrosis regions in group PEI-RFA was significantly larger (2.05 cm x 2.35 cm vs. 0.63 cm x 1.45 cm, 1.58 cm x 1.94 cm, 1.63 cm x 2.02 cm, P <0.05); the mean volume was greater [(6.33+/-2.86) cm(3) vs. (0.33+/-0.18) cm(3), (3.21+/-1.18) cm(3), (3.67+/-1.58) cm(3); P <0.05], and the isoperimetric ratio (parallel diameter/vertical diameter) was closer to 1.0 (0.87 vs. 2.36, 0.82, 0.80; P <0.05). In in vivo study, compared with those of groups PEI, RFA, and RFA-PEI, the mean size of necrosis regions in group PEI-RFA was significantly larger (1.92 cm x 2.22 cm vs. 1.00 cm x 1.56 cm, 1.17 cm x 1.55 cm, 1.23 cm x 1.64 cm; P <0.05); the mean volume was greater [(5.26+/-2.22) cm(3) vs. (0.93+/-0.61) cm(3), (1.60+/-0.87) cm(3), (1.90+/-1.15) cm(3); P <0.05], and the isoperimetric ratio was closer to 1.0 (0.87 vs 1.61, 0.75, 0.75; P <0.05).

RFA following PEI (PEI-RFA) increases the size and volume of necrosis region significantly, and makes the shape of necrosis region more similar to that of small liver cancer.