The pooled #HOPE4LIVER trials demonstrated the safety and technical success of the HistoSonics System for the destruction of liver tumors using histotripsy, a non-thermal, mechanical process of focused US.

Objective: To evaluate the 1-year clinical outcomes of patients enrolled in the #HOPE4LIVER trial of hepatic histotripsy. Background: Histotripsy is a novel noninvasive, non-thermal–focused ultrasound therapy that liquefies tissue at the focal point of the transducer. Following diagnostic ultrasound targeting, an automated treatment is performed through a robotic arm to treat a user-defined volume of tissue. Methods: Forty-seven patients were enrolled at 14 sites in the United States and Europe. Included patients were ineligible for or had opted out of standard therapies. Tumor control was evaluated through a core laboratory with a primary assessment at each time point and a post hoc assessment performed following the completion of each time point to allow for a learning curve of interpreting imaging findings of this novel therapy. Overall survival and freedom from local tumor progression were evaluated through the Kaplan-Meier method. Results: Nineteen patients with hepatocellular carcinoma and 28 with metastatic disease were enrolled, of whom 89.5% (17/19) and 96.4% (27/28) had multifocal hepatic tumors at the time of treatment. Fifty-two tumors were treated. The 1-year local control rate was 63.4% using the primary assessment method and 90% using the post hoc method. There were 6 serious adverse device-related effects within 30 days of treatment. Only one nonserious adverse device-related effect was observed after 30 days of treatment. Overall survival at 1-year was 73.3% for patients with hepatocellular carcinoma and 48.6% for patients with metastatic disease. Conclusions: Histotripsy results in local control of liver tumors at 1 year, which is consistent with current locoregional therapies. The safety profile is favorable, and survival at 1 year is comparable with other therapies for similar disease stages.

Creation of a VX2 tumor model has traditionally required a laparotomy and surgical implantation of tumor fragments. Open surgical procedures are invasive and require long procedure times and recovery that can result in post-operative morbidity and mortality. The purpose of this study is to report the results of a percutaneous ultrasound guided method for creation of a VX2 model in rabbit livers. A total of 27 New Zealand white rabbits underwent a percutaneous ultrasound guided approach, where a VX2 tumor fragment was implanted in the liver. Magnetic resonance imaging was used to assess for tumor growth and necropsy was performed to determine rates of tract seeding and metastatic disease. Ultrasound guided tumor implantation was successful in all 27 rabbits. One rabbit died 2 days following the implantation procedure. Two rabbits had no tumors seen on follow-up imaging. Therefore, tumor development was seen in 24/26 (92%) rabbits. During the follow-up period, tract seeding was seen in 8% of rabbits and 38% had extra-hepatic metastatic disease. Therefore, percutaneous ultrasound guided tumor implantation safely provides reliable tumor growth for establishing hepatic VX2 tumors in a rabbit model with decreased rates of tract seeding, compared to previously reported methods.