556 - Combined Intra-operative Percutaneous Microwave Liver Ablation with Robotic Ultrasound Image Guidance for Metastatic Neuroendocrine Tumor

Purpose: Minimally invasive robotic surgery for resection of enteropancreatic neuroendocrine tumors decreases the postoperative recovery period and pain {1}. However, liver metastases are often present at time of diagnosis which then require additional loco-regional therapies if resection is contraindicated {2}. The purpose of this study is to assess the safety of combined intra-operative percutaneous liver ablation under robotic image guidance in secondary tumors.

Materials and Methods: In this retrospective study, 16 tumors in 5 patients who underwent combined intra-operative percutaneous liver ablation under robotic ultrasound guidance from 7/2019 to 7/2025 were evaluated. Data collected included demographic, tumor characteristic, and procedural characteristics. Adverse events were categorized using the Society of Interventional Radiology adverse events classification.

Results: Total of 5 intra-operative percutaneous liver ablation sessions for 16 metastatic multifocal cancers in 5 patients were included. The mean patient age was 61.2 (51 – 71) years and 5/5 (100%) were male. The mean tumor size was 1.39 (0.5 -3.2) cm. Metastases comprised of pancreatic and small bowel neuroendocrine tumors. Microwave ablation was delivered at 65 watts using the Neuwave PR20XT probe (Johnson & Johnson Medtech) with a mean ablation length of 5.4 minutes. One patient developed a peri-pancreatic fluid collection post-operatively from a concurrent robotic pancreatectomy. No adverse events were noted related to the microwave ablation procedure.

Conclusion: Combined intra-operative percutaneous liver ablation with robotic image guidance appears to be a feasible option for the treatment of hepatic metastatic neuroendocrine tumor when performed concurrently with robotic pancreatoduodenectomy or robotic mesocolic excision to prevent conversion to open surgery or subsequent traditional percutaneous liver ablation.