Hepatic Resection vs Minimally Invasive Radiofrequency Ablation for the Treatment of Colorectal Liver Metastases

Abstract

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 the median 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.

Radiofrequency Ablation: Inflammatory Changes in the Periablative Zone Can Induce Global Organ Effects, including Liver Regeneration

“…RF ablation is widely and routinely successfully practiced as an anticancer therapy for both primary and metastatic focal liver tumors (25). However, despite long-standing knowledge of the presence of a "red" inflammatory rim surrounding the ablation zone (5), little is known about the organ environment and cellular responses to the thermal …”

Thermal ablation of colorectal liver metastases: a position paper by an international panel of ablation experts, the interventional oncology sans frontières meeting 2013

“…The question of where ablation fits in the overall management of patients with metastatic colorectal cancer is still being debated. In the last few years there have been numerous reviews of the ablation literature [13][14][15][16][17][18][19][20][21][22][23][24][25][26]. All of these have concluded that there is insufficient data, in particular randomised controlled trial (RCT) data, and as a result have had difficulty providing recommendations on the role of ablation.…”

Oncogenesis: An “Off-Target” Effect of Radiofrequency Ablation

“…This method facilitates thermal injury and thus cell death by means of coagulation necrosis to the tumor through electromagnetic energy deposition and is also used for the treatment of other malignant diseases in the liver, lung, kidney, and bone (9)(10)(11)(12). Beyond serving as a bridge to liver transplantation (13), RF ablation has significantly extended the life expectancy of many patients (14). Furthermore, RF ablation provides additional potential advantages over surgical resection owing to reduced morbidity by ablating a relatively small portion of the liver and can be performed as an outpatient therapy (15).…”