Hepatic resection vs minimally invasive radiofrequency ablation for the treatment of colorectal liver metastases: A Markov analysis

Hypothesis: Current literature evaluating radiofrequency ablation (RFA) for treatment of colorectal liver metastases describes high-risk surgical candidates or patients with unresectable disease. This creates bias when comparing RFA and hepatic resection. A Markov analysis would define theoretical outcomes necessary for RFA to demonstrate equivalence to resection. Design: A multistate Markov decision analytic model was constructed. Second-order Monte Carlo analysis was used to simulate a randomized controlled trial. Sensitivity analyses were performed to determine the projected outcomes necessary for RFA to achieve equivalence with resection. Setting: Tertiary care teaching hospital. Patients: A systematic review of published literature was performed, identifying studies involving patients with colorectal liver metastases treated with RFA or resection. Data were also included from a prospective database of patients undergoing laparoscopic RFA at our institution. Interventions: Percutaneous or laparoscopic RFA and hepatic resection. Main Outcome Measures: Quality-adjusted life expectancy and quality of life-adjusted survival. Results: The base-case analysis (60-year-old man) demonstrated a mean±SD quality-adjusted life expectancy of 5.67±0.71 years and a 5-year survival of 38.2% following resection. Based on current literature, the mean±SD quality-adjusted life expectancy for RFA was 3.61±0.49 years, with a 5-year survival of 27.2%. Sensitivity analyses demonstrated that RFA becomes the preferred strategy if themedian disease-free survival reaches 1.42 years. When limited to patients from our institution with resectable lesions, the quality-adjusted life expectancy for RFA improved to a mean±SD of 5.72±0.50 years. Conclusions: Classical Markov analysis demonstrates that based on current literature, resection is superior to RFA in the treatment of colorectal liver metastases. When input is limited to laparoscopic RFA in patients with resectable lesions, projected 5-year survival is superior to that of hepatic resection.