Perioperative Radiofrequency Ablation or Microwave Ablation of Colorectal Liver Metastases: A Single Centre Experience

Introduction: Radiofrequency ablation (RFA) and microwave ablation (MWA) are generally accepted to treat colorectal liver metastases (CRLM) with a curative intent. MWA is considered to have better outcomes than RFA but true comparing data are scarce. Methods: This single centre retrospective cohort study analysed 121 consecutive patients who underwent open surgery and ultrasound guided ablation between January 2013 and August 2018. The main objective was to compare RFA with MWA ablation outcomes, including local tumor progression per lesion (LTP), complete ablation rates per lesion, overall survival (OS), progression-free survival (PFS) and postoperative complication rates. Logistic regression models were used for univariable and multivariable analysis to identify predictors of LTP. Results: Forty-two patients underwent RFA of 96 lesions between 2013 and 2015 and 79 patients MWA of 192 lesions between 2015 and 2018. The median number of ablated CRLM was 2 (range 1-12) with a median diameter of 11 mm (range 1-31). Incomplete ablations were observed in 2 CRLM (2.1%) for RFA and 5 CLRM (2.6%) for MWA (p=0.787). LTP after complete ablation within one year occurred in 6 CRLM (6.3%) treated with RFA and in 11 CRLM (5.7%) treated with MWA (p=0.860). Complications after RFA and MWA requiring re-intervention (e.g. abscess and biloma drainage) within 30 days were observed in 2 (4.8%) and 6 (7.6%) patients, respectively (p=0.550). Ablation technique, operator (surgeon or interventional radiologist), size of ablated lesion and neoadjuvant chemotherapy were not associated with LTP. Conclusion: Perioperative RFA seems equally effective as MWA for CRLM up to 31mm.