Can Microwave Ablation be an Alternative to Resection for the Treatment of Neuroendocrine Liver Metastases?

Abstract

Objective: Surgical resection of neuroendocrine tumor liver metastases has been proven to improve survival, but the benefit of microwave ablation as an alternative or adjunct to surgery has yet to be assessed. Our hypothesis is that ablation is equal to surgery in terms of local recurrence and survival. Methods: We conducted a retrospective analysis including all patients treated with microwave ablation and/or surgical resection for neuroendocrine liver metastases in our institution between 2008 and 2017. Results: A total of 47 patients and 68 treatments were analyzed, including 34 liver resections, 20 ablations, and 14 combined procedures. A total of 130 individual metastases were treated with ablation, representing a median of 4 per session (range 1-30). While no major complications occurred after ablation, we observed 11 minor and 3 major complications after open surgical resection (P = .0135). Length of stay was significantly shorter after ablation (P = .0008). The majority of patients (33/47, 70.2%) underwent curative procedures, 14 patients underwent (29.8%) debulking procedures. There was no difference in local recurrence rate between tumors treated with ablation or resection. Liver-only disease progression was detected in 29% of the patients and overall progression was detected in 66% of the patients. The mean survival was not significantly different between patients treated with ablation only versus resection with or without ablation (P = .1570). Overall survival was mean 75.3 months (6 to 374 months). Conclusion: Depending on the extent of the liver metastases, microwave ablation might be a safe alternative or addition to resection for neuroendocrine tumor liver metastases with low morbidity and high local efficiency. Abbreviations: CT = computed tomography; MWA = microwave ablation; NET = neuroendocrine tumor; PET = positron emission tomography; RFA = radiofrequency ablation; RFS = recurrence-free survival; SMWA = stereotactic microwave ablation.