Abstract:Objective: Needle tract tumor seeding was one of the complications after RFA, the risk was not consistent as reported. The present study analysis of a retrospective data base of 117 patients with malignant liver tumor who had undergone RFA, with the aim to determine the incidence and the risk factors associated with tumor seeding after RFA. Materials and Methods: A retrospective data base of 117 patients with liver tumor who had undergone RFA in Shengjing Hospital from April 2005 to March 2008 was reviewed to identify the patients with needle tract tumor seeding. The rate of tumor seeding after RFA was determined and some of the risk factors were evaluated. Results: The tumor seeding was identified in 5 out of 117(4.3%) patients based on CT image findings, which corresponded to a rate of 5 of 128(3.9%) per treated lesion. All the patients with tumor seeding were identified within 6 months after RFA. Conclusion: RFA was an effective therepy for liver tumors with a low risk of needle tract tumor seeding. The risk factors associated with tumor seeding included no electrocoagulation of the electrode tract and subcapsular tumor location. A close follow up and recheck was necessary within half a year after RFA.