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Pilot study of partial ablation using high-intensity focused ultrasound (HIFU) in feline sarcomas


To determine if high-intensity focused ultrasound (HIFU), a treatment that can destroy tissue using sound waves, will result in tumor cell death and immunologic activation in cats with sarcomas.


Soft tissue sarcomas are a common form of cancer in cats, and are sometimes associated with injections or vaccines. They can invade tissues that are vital to normal function, and complete surgical removal can be impossible without amputation or radiation therapy. In some cases, a tumor may be removable by surgery, but it could still recur at the surgical site or in a distant site like lymph node or lung.

One attractive option for such cases is immunotherapy. We propose using mechanical high-intensity focused ultrasound (HIFU) to kill tumor cells and release antigens from tumors, stimulating the patient’s anti-tumor immune response. We hope to find out if HIFU application can both kill tumor cells and activate the immune system in cats. To determine if the treatment is effective, we are recruiting cats with soft tissue sarcomas located in the skin to undergo HIFU treatment prior to surgical removal of the tumor.

This study is funded by the Focused Ultrasound Foundation.


  • Cats with a diagnosis of a soft tissue sarcoma that is at least 3 cm in diameter. Cats must currently have a measurable tumor in order to enroll.
  • Tumor must be able to be removed by surgery, and owner must agree to surgery
  • Life expectancy of at least six weeks
  • Free from serious systemic illness


  • Cats who have received any tumor-directed therapy (e.g. radiation) or immunosuppressive drugs within 4 weeks prior to study enrollment
  • Cats who have received chemotherapy within three weeks prior to study enrollment

Study Design

Prior to enrolling in the study, your cat must undergo cancer staging, including a complete physical exam, lab work, tumor biopsy and a CT scan. These procedures are at owner expense.

If your cat meets the eligibility criteria, s/he will be scheduled for the HIFU treatment within ten (10) days of enrollment. HIFU will be applied to the tumor under general anesthesia. Your cat’s fur/hair will be clipped over the tumor as is standard for any ultrasound in cats. The treatment will be delivered in a series of bursts of sound that will be focused on the tumor to kill the cancerous cells through unbroken skin surface. The HIFU treatment is expected to take 30-60 minutes, but may take longer for some patients. Your cat may be sent home the same day, or if due to timing of the treatment or for the safety of your pet, s/he may need to stay overnight while recovering from anesthesia. Your cat's surgery will take place at the Veterinary Teaching Hospital in Blacksburg, VA 4-6 days following treatment. Your cat will be discharged according to standard procedures, based on the surgeon’s discretion. Your cat will return for a recheck 2 weeks after the surgery.


The screening (eligibility) tests, surgery, and post-surgery recheck visits are not fully covered by the study. Your total out of pocket costs are estimated to be between $2900 and $3400.

Screening: Labwork and chest x-rays cost, approximately $900 if performed at ACCRC. If performed by your regular veterinarian, they can be sent to ACCRC to begin the screening process. Tests and images of insufficient quality will not be accepted. An exam and CT scan with the oncologists at ACCRC will be necessary to fully determine whether your cat is eligible to enroll.

Baseline visit: If, at the baseline CT scan, the surgeons deem that the tumor cannot be safely removed or you do not agree to the recommended surgery, the cost of the CT scan and biopsy will be out-of-pocket at $2000.

Surgery: If your cat is enrolled, it is expected that the surgery visit out-of-pocket fees will be $2000-2500.

Once your cat is eligible and enrolled, the study will provide $5,000 worth of diagnostics, treatment, and medical care. Specifically: The entire cost of the baseline CT scan and radiologist interpretation, up to $350 for general anesthesia for the CT scan, $250 for the biopsy and histopathology, the exam fees and study-required labwork, up to $350 for the general anesthesia and HIFU/histotripsy treatment, and $2,000 of the cost of the surgery visit. You are responsible for any clinical fees exceeding the above costs, fees for surgery and post-operative care exceeding $2,000, any fees associated with medical complications of the HIFU therapy, and diagnostics or treatments performed not associated with the study or other medical problems that arise during the study. 


Mindy Quigley, Clinical Trials Coordinator
Office Phone: 540-231-1363 | Email:

Dr. Shawna Klahn, Medical Oncology
Phone: 540-526-2300 | Email:

If your query is urgent, please call the Animal Cancer Care and Research Center on 540-526-2300.

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