CT-guided Radiofrequency Ablation as a Salvage Treatment of Colorectal Cancer Hepatic Metastases Developing after Hepatectomy

Purpose: To evaluate the clinical outcomes of percutaneous radiofrequency (RF) ablation of colorectal cancer liver metastases (CLMs) that recur after hepatectomy. Materials and Methods: From December 2002 to December 2008, 71 CLMs that developed after hepatectomy were ablated in 56 patients. Medical records and imaging were reviewed to determine technique effectiveness/complete ablation (ie, ablation defect covering the entire tumor on 4-6-week postablation computed tomography [CT]), complications, and local tumor progression (LTP) at the site of ablation. LTP-free and overall survival were calculated by using Kaplan-Meier methodology. A modified clinical risk score (CRS) including nodal status of the primary tumor, time interval between diagnoses of the primary tumor and liver metastases, number of tumors, and size of the largest tumor was assessed for its effect on overall survival and LTP. Results: Tumor size ranged between 0.5 and 5.7 cm. Complete ablation was documented in 67 of 71 cases (94%). Complications included liver abscess (n = I) and pleural effusion (n = 1). Median overall survival time was 31 months. One-, 2- and 3-year overall survival rates were 91%, 66%, and 41%, respectively. CRS was an independent factor for overall survival (74% for CRS of 0-2 vs 42% for CRS of 3-4 at 2 y; P = .03) and for LTP-free survival (66% for CRS of 0-2 vs 22% for CRS of 3-4 at 1 y after a single ablation; P < .01). Conclusions: CT-guided RF ablation can be used to treat recurrent CLM after hepatectomy. A low CRS is associated with better clinical outcomes.