VCOM Research Day Program Book 2023

Faculty Research Biomedical

Alayna Hay 1 ; Haleigh Hixson 1 ; Alex Simon 2 ; Lauren Ruger 2 ; Jessica Gannon 2 ; Sheryl Coutermarsh-Ott 1,3 ; William Eward 4 ; Eli Vlaisavljevich 2 ; Nathan Neufeld 5 ; Joanne Tuohy 1 Corresponding author: jltuohy@vt.edu 02 Investigating the Feasibility of IN-VIVO Histotripsy Ablation for Osteosarcoma Using an Orthotopic Murine Model 1 Virginia Maryland College of Veterinary Medicine, 2 Virginia Tech, 3 Virginia Department of Agriculture and Consumer Services, 4 Duke Cancer Center, 5 VCOM Medicine, CTCA Pain and Palliative Care Program

Osteosarcoma (OS) is the most commonly occurring primary bone tumor in pediatric cancer patients and dogs, with estimated incidences of 3-4 cases per 1 million and 14 cases per 100,000, respectively. Current standard of care treatment results in a 70% median 5-year survival for humans and a 10-12-month median survival for dogs, and these survival expectations have not improved in 30 years. There is a critical need for novel treatment options to improve the prognosis for OS patients. The objective of this study was to investigate the ablative effects of

a novel focused ultrasound tissue ablation technique, histotripsy, in OS. We utilized orthotopic xenograft murine models with induced canine (D17) or human (143B) OS tumors. Ablative outcomes were assessed grossly and microscopically, and treatment effects on limb functionality were evaluated by monitoring lameness, grip capacity, nesting behavior, and body weight. Ablation was evident by histopathological evaluation where loss of cellular architecture, lytic and coagulative necrosis and delineation of treated and untreated tumor regions were observed.

Inflammation after histotripsy ablation resolved within 5-7 days and limb function returned to status prior to histotripsy treatment (143B and D17 groups) and/or resolved lameness due to decreased tumor size (D17 group). In conclusion our results suggest that histotripsy treatment has ablative potential for OS and support further investigation.

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