Katherine C Longo1, Emily A Knott2, Rao F Watson3, John F Swietlik2, Eli Vlaisavljevich4, Amanda R Smolock5, Zhen Xu6, Clifford S Cho7, Lu Mao8, Fred T Lee2,9,10, Timothy J Ziemlewicz2. 1. Department of Radiology, University of Wisconsin Hospital and Clinics, 600 Highland Ave, Madison, WI, 53705, USA. klongo@uwhealth.org. 2. Department of Radiology, University of Wisconsin Hospital and Clinics, 600 Highland Ave, Madison, WI, 53705, USA. 3. Department of Pathology, University of Wisconsin, Madison, USA. 4. Department of Biomedical Engineering and Mechanics, Virginia Polytechnic and State University, Blacksburg, USA. 5. Division of Interventional Radiology, Department of Radiology, University of Pennsylvania, Philadelphia, USA. 6. Department of Biomedical Engineering, University of Michigan, Ann Arbor, USA. 7. Department of Surgery, University of Michigan, Ann Arbor, USA. 8. Department of Biostatistics and Medical Informatics, University of Wisconsin, Madison, USA. 9. Department of Biomedical Engineering, University of Wisconsin, Madison, USA. 10. Department of Urology, University of Wisconsin, Madison, USA.
Abstract
PURPOSE: Robotically assisted sonic therapy (RAST) is a nonthermal, noninvasive ablation method based on histotripsy. Prior animal studies have demonstrated the ability to create hepatic ablation zones at the focal point of an ultrasound therapy transducer; however, these treatments resulted in thermal damage to the body wall within the path of ultrasound energy delivery. The purpose of this study was to evaluate the efficacy and safety of a pulse sequence intended to mitigate prefocal body wall injury. MATERIALS AND METHODS: Healthy swine (n = 6) underwent hepatic RAST (VortxRx software version 1.0.1.3, HistoSonics, Ann Arbor MI) in the right hepatic lobe. A 3.0 cm spherical ablation zone was prescribed for each. Following treatment, animals underwent MRI which was utilized for ablation zone measurement, evaluation of prefocal injury, and assessment of complications. Each animal was euthanized, underwent necropsy, and the tissue was processed for histopathologic analysis of the ablation zone and any other sites concerning for injury. RESULTS: No prefocal injury was identified by MRI or necropsy in the body wall or tissues overlying the liver. Ablation zones demonstrated uniform cell destruction, were nearly spherical (sphericity index = 0.988), and corresponded closely to the prescribed size (3.0 × 3.1 × 3.4 cm, p = 0.70, 0.36, and 0.01, respectively). Ablation zones were associated with portal vein (n = 3, one occlusive) and hepatic vein thrombosis (n = 4, one occlusive); however, bile ducts remained patent within ablation zones (n = 2). CONCLUSIONS: Hepatic RAST performed with a modified ultrasound pulse sequence in a porcine model can mitigate prefocal body wall injuries while maintaining treatment efficacy. Further study of hepatic RAST appears warranted, particularly in tumor models.
PURPOSE: Robotically assisted sonic therapy (RAST) is a nonthermal, noninvasive ablation method based on histotripsy. Prior animal studies have demonstrated the ability to create hepatic ablation zones at the focal point of an ultrasound therapy transducer; however, these treatments resulted in thermal damage to the body wall within the path of ultrasound energy delivery. The purpose of this study was to evaluate the efficacy and safety of a pulse sequence intended to mitigate prefocal body wall injury. MATERIALS AND METHODS: Healthy swine (n = 6) underwent hepatic RAST (VortxRx software version 1.0.1.3, HistoSonics, Ann Arbor MI) in the right hepatic lobe. A 3.0 cm spherical ablation zone was prescribed for each. Following treatment, animals underwent MRI which was utilized for ablation zone measurement, evaluation of prefocal injury, and assessment of complications. Each animal was euthanized, underwent necropsy, and the tissue was processed for histopathologic analysis of the ablation zone and any other sites concerning for injury. RESULTS: No prefocal injury was identified by MRI or necropsy in the body wall or tissues overlying the liver. Ablation zones demonstrated uniform cell destruction, were nearly spherical (sphericity index = 0.988), and corresponded closely to the prescribed size (3.0 × 3.1 × 3.4 cm, p = 0.70, 0.36, and 0.01, respectively). Ablation zones were associated with portal vein (n = 3, one occlusive) and hepatic vein thrombosis (n = 4, one occlusive); however, bile ducts remained patent within ablation zones (n = 2). CONCLUSIONS: Hepatic RAST performed with a modified ultrasound pulse sequence in a porcine model can mitigate prefocal body wall injuries while maintaining treatment efficacy. Further study of hepatic RAST appears warranted, particularly in tumor models.
Authors: Emily A Knott; Katherine C Longo; Eli Vlaisavljevich; Xaiofei Zhang; John F Swietlik; Zhen Xu; Allison C Rodgers; Annie M Zlevor; Paul F Laeseke; Timothy L Hall; Fred T Lee; Timothy J Ziemlewicz Journal: Cardiovasc Intervent Radiol Date: 2021-07-09 Impact factor: 2.740
Authors: Alissa Hendricks-Wenger; Margaret A Nagai-Singer; Kyungjun Uh; Eli Vlaisavljevich; Kiho Lee; Irving C Allen Journal: Methods Mol Biol Date: 2022
Authors: Emily A Knott; Annie M Zlevor; J Louis Hinshaw; Paul F Laeseke; Colin Longhurst; Jenifer Frank; Charles W Bradley; Allison B Couillard; Annika E Rossebo; Zhen Xu; Fred T Lee; Timothy J Ziemlewicz Journal: Eur Radiol Date: 2022-09-01 Impact factor: 7.034
Authors: Alissa Hendricks-Wenger; Lauren Arnold; Jessica Gannon; Alex Simon; Neha Singh; Hannah Sheppard; Margaret A Nagai-Singer; Khan Mohammad Imran; Kiho Lee; Sherrie Clark-Deener; Christopher Byron; Michael R Edwards; Martha M Larson; John H Rossmeisl; Sheryl L Coutermarsh-Ott; Kristin Eden; Nikolaos Dervisis; Shawna Klahn; Joanne Tuohy; Irving Coy Allen; Eli Vlaisavljevich Journal: IEEE Trans Ultrason Ferroelectr Freq Control Date: 2021-12-31 Impact factor: 3.267
Authors: Alissa Hendricks-Wenger; Jacqueline Sereno; Jessica Gannon; Allison Zeher; Rebecca M Brock; Natalie Beitel-White; Alexander Simon; Rafael V Davalos; Sheryl Coutermarsh-Ott; Eli Vlaisavljevich; Irving Coy Allen Journal: IEEE Trans Ultrason Ferroelectr Freq Control Date: 2021-08-27 Impact factor: 3.267