The Master of Science Seminar and Examination of Jennifer Carroll

Biography

Jennifer completed her medical oncology residency at Virginia Tech in 2021 and is currently working in Pennsylvania. She has a special interest in minimally invasive cancer ablation techniques and the impact various techniques can have on the local tumor microenvironment and systemic immunity.

Funded by

• Veterinary Cancer Society Thelien Resident Grant 
• Grayton Frielander Memorial Fund 
• Focused Ultrasound Foundation 
• VMF 
• Virginia-Maryland College of Veterinary Medicine Office of Research and Graduate Studies

Awards and Academic Achievements

• January 2023: Diplomate of the ACVIM of Oncology

Lay Language Abstract 

Surgery is generally considered the treatment of choice for solid tumors because it can extend survival and make cancer patients feel better. Unfortunately, not everyone is a good candidate for surgery. Tumor ablation, a term used to describe techniques that use various methods to destroy tumors in a minimally invasive way, has the ability to help cancer patients who are ineligible for surgery. Additionally, it may also help the body fight the cancer. 

In our first study, we looked at using High Intensity Focused Ultrasound (HIFU) to treat solid tumors in dogs. Our objectives were to see if it was safe and if it could change the tumor in a way that might help the body fight the cancer. We recruited dogs with solid tumors and performed scans to localize the tumors. We took samples of the tumors before treatment with HIFU. We subsequently removed the tumors. We also looked to see if treatment altered the genes inside the tumors.  

Microscopic evaluation of tissue samples showed that HIFU was effective in killing the tumors with an increase in IBA-1+ immune cells at the border between the destroyed and untreated portions. Expression of 28 genes changed after treatment and suggests the environment inside the tumor is more inflamed. 

In our second study, we looked at using High-Frequency Irreversible Electroporation (H-FIRE) to treat liver cancer in dogs. Based on previous research, we thought that H-FIRE might be able to kill cancer cells while sparing normal liver. Our objective was to see how both liver cancer and normal liver respond to H-FIRE. We recruited dogs with liver cancer and used H-FIRE to treat the tumor and a small portion of normal liver. Our treatment settings were based on previous studies and personalized 3D modeling. After treatment, we removed a sample of the tumor. We performed follow-up scans at various timepoints to see how the normal liver tissue responded. We evaluated tumor samples under the microscope and analyzed the levels of certain molecules in the blood as well as the genes in tumors following treatment. 

We treated three dogs without complications. Examination of the treated tumor showed complete destruction. Follow-up scans suggested that normal liver was affected to a lesser extent when compared to tumor. We also found hints that H-FIRE might trigger the body's immune system to fight cancer. 

Both studies suggest that tumor ablation is effective, generally safe, and may help the body fight cancer. More research is needed to confirm our results and to understand the immune system’s response to treatment. 

Publications

“First report of primary tonsillar salivary gland adenocarcinoma in a dog”. Vet Rec Case Rep. 2024;e827. https://doi.org/10.1002/vrc2.827 

"High Intensity Focused Ultrasound for the Treatment of Solid Tumors: A pilot study in canine cancer patients”.  Int J Hyperthermia. 2022;39(1):855-864.doi:10.1080/02656736.2022.2097323

“Focused ultrasound tumour ablation in small animal oncology”. Vet Comp Oncol. 2021 Sep;19(3):411-419. doi:10.1111/vco.12742 

Presentations

• Early feasibility trial of High-Frequency Irreversible Electroporation (H-FIRE) for the treatment of canine hepatocellular carcinoma; Poster presentation VCS 2021  
• High Intensity Focused Ultrasound For Treatment Of Subcutaneous Solid Tumors In Dogs; Recorded Virtually VCS, 2020   
• 7th International Symposium on Focused Ultrasound 2020; Virtual Meeting November 9-13th 2020  
• First In Patient Trial of High Intensity Focused Ultrasound (HIFU) For Treatment Of Canine Solid Tumors; Presented VCS, Houston 2019     

Examination Graduate Committee

Major Advisor/Chair:

Nikolaos Dervisis DVM, PhD, DACVIM-Oncology 
Associate Professor Medical Oncology 
Department of Small Animal Clinical Sciences; VA-MD College of Veterinary Medicine 

Graduate Advising Committee Members:

Shawna L Klahn, DVM, DACVIM-Oncology 
Associate Professor Medical Oncology 
Department of Small Animal Clinical Sciences; VA-MD
College of Veterinary Medicine 

Sheryl Lynn Coutermarsh-Ott,DVM,PhD, DACVP 
Virginia Department of Agriculture and Consumer Services, Adjunct Faculty Department of Biomedical Sciences and Pathobiology 

Eli Vlaisavljevich, PhD 
Associate Professor 
Department of Biomedical Engineering and Mechanics