This CT slice of a dog’s nose shows the nasal cavity to be full of tumor (gray area inside the white outline). After a cryoablation treatment, the tumor has been almost completely eliminated.
Dr. Michele Steffey is making great strides in the fight against cancer with multiple innovative procedures at the UC Davis Veterinary Medical Teaching Hospital. Her cutting-edge approaches may revolutionize the treatment of cancer in veterinary patients. Many of these procedures are in the clinical trial phase, and are seeing success as potential new standard protocols.
• Near-infrared fluorescence operative imaging
This exciting new form of surgical imaging uses an injectable tracer pharmaceutical that is detected by a special imaging system at very low doses, with a very high sensitivity, to highlight specific structures in the surgical field that otherwise may be unseen with the naked eye. In the context of cancer surgery, this provides the potential for improvement in the identification of tumors, identification of lymph nodes that should be examined for metastatic disease, and delineation of surgical margins. These improvements increase operative accuracy and decrease surgical time. Unlike many other types of imaging, there is no radiation dose to the patient with near-infrared fluorescent imaging, and this modality can be used in minimally-invasive surgery, as well as traditional open procedures. This exciting technique has also been extremely useful in identifying branches of the thoracic lymphatic duct at surgery, and is being applied to the treatment of chylothorax in dogs and cats with great success.
• Percutaneous cryoablation
This method of killing cancerous cells by freezing is achieved through the use of specialized hollow cryoprobes to freeze tumors located deep in the body in a minimally-invasive manner. Excitingly successful preliminary results are being achieved in a study evaluating treatment of intranasal tumors (within the nasal cavity) in this manner. With harder to reach tumors, such as bone tumors, larger surgical incisions may be necessary, but successful applications have the potential to spare some animals from amputation (which is currently the standard recommendation for this disease). Cryoablation is currently used in human health care for treatment of kidney, prostate, bone, lung and liver tumors.
• CT pneumocolonography
This imaging protocol has been developed for CT of colonic and rectal disease. Historically, CT has not been used in veterinary medicine for imaging the gastrointestinal (GI) tract because it remains collapsed when empty, making it difficult to accurately assess the extent of GI disease. In this protocol, the colon is inflated with gas to improve the anatomic understanding of relationships between normal and abnormal structures. An optimal protocol has been determined, and all patients with large bowel disease, whether cancer is suspected or not, are candidates for this new imaging technique. Preliminarily, we are finding that this technique improves surgical planning in dogs with cancer of the colon or rectum. Its potential role in differentiating benign from malignant disease is under active investigation.
• Interventional Oncology: Chemoembolization and Palliative Stenting
These palliative treatments of non-resectable tumors use specialized stents, catheters and the targeted delivery of chemotherapy directly to the tumor in order to improve quality of life. In chemoembolization, a mixture of chemotherapy and agents to block the tumor’s blood supply are delivered directly to the tumor with lower risk of systemic complications. Stents are used to address obstructions in the respiratory, GI, or urinary tracts. These minimally-invasive treatments are performed under general anesthesia and use fluoroscopy and either very small skin incisions or natural orifices; therefore, pain associated with the procedures is minimal, and recovery is quick.
Dr. Steffey is faculty member in the VMTH’s Soft Tissue Surgery Service. She is board certified in veterinary surgery, and is one of only 35 veterinarians worldwide who are Founding Fellows in Surgical Oncology in the American College of Veterinary Surgeons.
About the Veterinary Medical Teaching Hospital
The William R. Pritchard Veterinary Medical Teaching Hospital at the University of California, Davis—a unit of the School of Veterinary Medicine—provides state-of-the-art clinical care while serving as the primary clinical teaching experience for DVM students and post graduate veterinarian residents. The VMTH treats more than 45,000 animals a year, ranging from cats and dogs to horses, cows and exotic species. To learn more about the VMTH, please go to http://www.vetmed.ucdavis.edu/vmth. Timely news updates can be received on its Facebook (www.facebook.com/ucdavisvetmed) and Twitter (www.twitter.com/ucdavisvetmed) pages.
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