Safety and efficacy of microwave ablation for medically inoperable colorectal pulmonary metastases: Single-centre experience.

INTRODUCTION: To evaluate the safety and therapeutic efficacy of percutaneous microwave ablation (MWA) for colorectal pulmonary metastases.

METHODS: Retrospective review of CT-guided lung MWA at a single tertiary institution. Adverse events within 30 days of MWA were considered procedure-related complications. Imaging follow-up was with 18F-fluorodeoxyglucose (FDG) positron emission tomography (PET)/CT and contrast-enhanced CT. Response of index tumours was assessed using modified response evaluation criteria in solid tumours (mRECIST).

RESULTS: The CT-guided lung MWA was performed in 14 patients with treatment of 20 colorectal pulmonary metastases during 19 procedures. Mean follow-up from completion of the treatment protocol was 24.4 ± 11.8 months. Primary and secondary technique effectiveness rates were 75% and 50% respectively. Mean pre- and post-procedural carcino-embryonic antigen (CEA) levels were 7.9 ± 10.8 µg/L and 2.5 ± 2.1 µg/L respectively. Procedure-related complications were major in three procedures (15.8%) and minor in six procedures (31.6%). No procedure-related deaths occurred.

CONCLUSION: Microwave ablation is safe and efficacious in the local control of colorectal pulmonary metastases. The frequent systemic disease progression despite local control would favour a minimally invasive treatment option over invasive surgery in the setting of oligometastatic disease.