The role of microwave ablation as an alternative or adjunct to resection of neuroendocrine liver metastases

Abstract

Background: Surgical resection of neuroendocrine tumor liver metastases (NETLM) has been proven to improve survival, but the benefit of microwave ablation (MWA) as a minimally invasive, tissue-sparing alternative to curative surgery or debulking procedure has yet to be assessed. We present our center’s experience with MWA and/or surgery for NETLM in terms of safety and recurrence rates. Methods: Retrospective study including all patients treated with MWA and/or resection for NETLM between 2000 and 2017. Follow-up consisted in 3-monthly imaging according to the recommendation of the interdisciplinary conference. Results: A total of 47 patients, median age 60 years (27-76), were included in this analysis, receiving 68 interventions. Patients underwent between 1 and 4 interventions, including 34 liver resections (6 laparoscopic, 28 open), 20 MWAs (12 percutaneous, 8 open), and 14 combined procedures (3 laparoscopic, 11 open). A total of 130 individual lesions were treated with MWA, representing 4 lesions per session (1-30). While no complications occurred after MWA, after open resection 9 patients needed drainage for 8 biliomas and 1 abscess (IIIa) and 1 patient was transplanted for liver failure (IVb). The majority of patients (33/47, 70.2%) received curative procedures, 14 patients (29.8%) debulking procedures. Two patients (4.3%) had a local recurrence at the ablation site, both combined with disease progression in the liver. One patient (2.1%) had a recurrence at the resection site and underwent successful re-resection. Liver-only disease progression occurred in 17% of patients and overall progression in 47%, after median 7 months (range 0-43). Mean survival was not significantly different between the debulking and curative group (38.9 (SD 20.1) and 50.8 (SD 38.8) months respectively, p=0.2288). Conclusion: MWA might be a safe alternative or addition to resection for NETLM with low complication and local recurrence rates, allowing a liver-sparing minimal invasive treatment of this often recurring chronic disease.