A multiple microwave ablation strategy in patients with initially unresectable colorectal cancer liver metastases - A safety and feasibility study of a new concept.

AIMS: Resection for colorectal cancer liver metastases is indicated when an R0 resection with preservation of a sufficient future liver remnant (FLR) is achievable. Multimodality conversion of initially unresectable patients to resectable is possible in some patients. We present results of a downstaging strategy using microwave ablation (MWA). PATIENTS AND METHODS: In patients where resection was precluded by absence of a tumour-free FLR due to the extent of segmental tumour engagement, but with the potential to clear the whole liver with multiple local ablations, MWA was performed at laparotomy using ultrasound guidance or computer-assisted navigation. Mortality and morbidity was recorded and the overall and disease-free survival of the ablated patients was compared to data of two historic cohorts.
RESULTS: Ten of twenty treated patients were alive at median follow-up 25 months. There was no perioperative mortality, with MWA-associated complications being mild to moderate. The MWA group showed a 4-year overall survival of 41%, compared to 70% for a historic cohort of primarily resected patients and 4% for patients with palliative treatment.
CONCLUSION: Results of the multiple ablation strategy in the defined population suggest a survival benefit, compared to palliative chemotherapy alone with acceptable associated morbidity and no perioperative mortality.