Safe and Effective Histotripsy Ablation of Human Liver Tumors in a Genetically Modified Porcine Model.

BACKGROUND: Liver cancers are a major cause of morbidity and mortality in patients where effective, non-invasive treatment options remain limited. OBJECTIVE: Histotripsy is a non-invasive, non-thermal, image-guided focused ultrasound method of ablation that mechanically disrupts cells and offers a range of potential advantages over other ablation modalities. The lack of physiologically and anatomically relevant animal models of human liver cancer has significantly hindered biomedical device development, including histotripsy. METHODS: To address these limitations, we developed a clinically relevant large animal orthotopic, dual-tumor model of human liver cancer and utilized these unique animals to evaluate the safety and efficacy of histotripsy. Here, we utilized immunocompromised pigs with genetic modifications in their IL-2RG and RAG2 genes and orthotopically engrafted human hepatocellular carcinoma (HepG2/C3A) and pancreatic adenocarcinoma (Panc-1) cells within the liver. The models were designed to recapitulate primary and metastatic liver tumor phenotypes. RESULTS: Histotripsy enabled real-time visualization of the treatment by the formation of bubble clouds and accurate targeting of the lesions. Histological analysis confirmed the engraftment of tumor cells and the ablation of targeted tissue. Serum biomarkers demonstrated no significant differences in bilirubin, ALT, ALKP, or CK post-treatment, suggesting that histotripsy treatment was well tolerated with minimal hepatic dysfunction or hepatocellular injury. CONCLUSIONS: These findings establish a novel, clinically relevant porcine model of primary and metastatic liver tumors and demonstrate the safety and feasibility of using this model for evaluating histotripsy as a noninvasive modality for precise tumor ablation.