Abstract No. 144 Percutaneous Thermal Ablation of Metastatic Prostate Cancer to the Liver: A Single-Center Retrospective Study

To evaluate the efficacy and safety of percutaneous thermal ablation of prostate cancer liver metastases. This single-center retrospective analysis included patients from 2005 to 2022. Forty-four patients were treated with 54 procedures for 90 lesions (Table 144.1). All percutaneous liver ablation procedures were performed under imaging guidance and general anesthesia. Follow-up imaging was assessed for residual disease, local tumor progression, and intrahepatic and extrahepatic progression. The median size of treated lesions was 1.6 cm (range 0.4-11.6), and the median number of lesions treated per patient was 2 (range 1-5). Of 90 total lesions, 67 (74%) lesions were treated with microwave ablation (MW), and 23 (26%) were treated with radiofrequency ablation (RFA). The overall survival for the entire cohort was 85.8% at 6 months, 58.6% at 1 year, and 35.7% at 2 years. Local tumor progression-free survival (LPFS) for the entire cohort was 98.9% at 1 month, 80.0% at 6 months, 64.2% at 1 year, and 59.9% at 2 years. LPFS also varied with respect to treatment modality; patients treated with MW demonstrated better LPFS (83.0% at 6 months and 72.8% at 12 months) compared with those treated with RFA (70.3% at 6 months and 42.2% at 12 months, P = 0.04). Percutaneous thermal ablation of prostate cancer liver metastases is a safe intervention with high rates of local control. In this single arm study, the median overall survival rate was greater than similar cohorts from the literature. Locoregional approaches to treat liver metastases may provide improvements in overall outcomes in this patient population.