An experimental protocol for in situ colorectal liver metastases ablation by radiofrequency toward a standard procedure.

BACKGROUND: Radiofrequency ablation (RF) is already a viable alternative to surgical resection for focal liver tumors treatment. The use of RF ablation in combination with surgery or chemotherapy and the large panel of RF tools need new experimental models to develop new opportunities for this kind of therapy. PURPOSE: The purpose of this study was to identify the optimal RF parameters that will allow in situ colic cancer liver metastases destruction with minimal secondary effects. MATERIALS AND METHODS: The CC531s colic cancer tumor cells were used to induce liver metastases in 30 synergic Wag/Rij rats. When metastases reached at least 1 cm in diameter, RF generator RITA 1500X, and expandable tip RF probe Starburst SDE (Angiodynamics, USA) was used for the RF ablation. The animal survival rate and the RF-induced lesions have been studied, while only the generator delivered power has been modified (90W, 20W, and 10W, respectively). RESULTS: Survival was significantly low in the group with 90W-delivered power RF. Moreover, statistically significant differences were revealed between groups with high and low RF power, regarding the morphological changes of the liver parenchyma and the adjacent organs, without significant difference on the RF therapeutically effect. CONCLUSIONS: In an experimental setting, an increased RF generator power induces important lesions of the abdominal organs with subsequently important mortality rate, without improving the RF therapeutic efficiency.