Safety and Clinical Efficacy of Histotripsy for Liver Cancers Adjacent to Major Intrahepatic Vessels

Malignant liver tumors are among the most common malignancies worldwide, with over 10,000 new cases diagnosed annually in Taiwan. Despite the variety of treatment options currently available for malignant liver tumors, the prognosis for patients with primary hepatocellular carcinoma or metastatic liver cancer remains disheartening. More than 8,000 people die from the disease each year. The majority of patients (approximately 70% to 85%) are diagnosed at an advanced stage or have tumors that are unresectable. In contrast, patients with smaller tumors have a much better chance of achieving a cure. Numerous studies have reported that patients who undergo hepatic lobectomy have a 5-year disease-free survival rate exceeding 50%. For tumors that are not surgically resectable, local ablation techniques such as Radiofrequency Ablation (RFA) have emerged as potentially curative alternatives. However, RFA has significant drawbacks: its percutaneous invasiveness can sometimes lead to bleeding or tumor seeding along the needle tract, and it may be less effective near blood vessels due to the heat-sink effect. Therefore, its application is currently limited to small liver tumors. Histotripsy is a tumor ablation technique developed in recent years that allows for non-invasive treatment of solid tumors using High-Intensity Focused Ultrasound (HIFU). This method works by physically focusing ultrasound energy at a single point within biological tissue, creating a focal zone of high-power, low-frequency ultrasound that induces mechanical fragmentation (histotripsy) and cavitation effects, dissolving the tissue into fragments and destroying tumor cells. Under real-time ultrasound imaging guidance, various scanning treatment protocols are used to move the focal point throughout the treatment zone, effectively ablating the tumor tissue. This clinical trial utilizes the Edison System, developed by HistoSonics Inc. (USA). The first multicenter Phase I human trial of this technology was co