Clinical analysis of the treatment of recurrence after liver metastasis of colorectal cancer by radiofrequency ablation under percutaneous ultrasound

Interventions: repeat hepatic resection group vs. RFA group:repeat hepatic resection vs. RFA
Primary outcome(s): Overall survival;Disease-free survival
Study Design: Non randomized control

干预措施：重复肝切除术组与射频消融（RFA）组，即比较重复肝切除术与射频消融的疗效。
主要结局指标：总生存期（Overall survival）、无病生存期（Disease-free survival）。
研究设计：非随机对照研究。