This technology monitors for spread of tumors
A pet’s cancer diagnosis triggers owners’ emotional strain, confusion, and uncertainty about treatment and financial decisions. Thankfully, with the help of engineers and veterinarians at the University of Illinois, cancer detection and treatment in pets—and people—is advancing at rapid speed.
One of the many studies currently taking place at the University of Illinois Veterinary Teaching Hospital in Urbana involves more accurate detection of metastasis (spread of cancer through the body) for head and neck tumors. Dr. Laura Selmic, a veterinary surgeon who specializes in surgical oncology, is leading this study. The study evaluates new technology, developed by Dr. Viktor Gruev at the College of Engineering, that may help cancer specialists relieve some of the uncertainty about treatment decisions.
This is cutting-edge technology. It benefits pets significantly and helps doctors understand how the cancer is behaving and how to treat it. … eventually, the goal is for this technology to be used in human medicine as well.
Dr. Laura Selmic
Head and Neck Tumors
“Head and neck masses in dogs can be caused by a variety of cancers,” Dr. Selmic says. “Common ones are oral tumors, mast cell tumors (tumor of the immune system), or tumors from other parts of the body that have spread.”
The location of head and neck tumors makes them difficult to remove successfully. Vital structures, such as arteries that supply the head and nerves that travel from the brain to the rest of the body make surgery a very cautious procedure. “Many tumors in this area can also be extremely aggressive, such as oral melanoma tumors,” Dr. Selmic explains. “This means that if we miss even a little bit of the tumor or tumor spread, it can return quickly and cause more problems.”
Life expectancy varies for dogs afflicted by head and neck tumors. If the cancer is successfully treated and the tumor fully removed, the dog can have a normal life span. However, survival time can be as little as 6 to 9 months for dogs with oral melanoma. Being able to detect and monitor the tumor when it is still small can increase the length and quality of life of the patient.
The Role of Lymph Nodes
Monitoring for tumor spread is done primarily by monitoring lymph nodes. Lymph nodes are essentially the headquarters of the body’s immune system. They monitor the body for any infections or problems and sends cells to attack and break down invading bacteria, viruses, or cancer cells. To do this, the lymph system filters fluid and cells from all parts of the body—including tumors that have advanced past a certain point. When a tumor is mature enough to drain into a lymph node, cancer cells can spread to any part of the body.
“There is typically one lymph node the tumor drains into first, and this one can be tested for metastasis to see if the tumor is spreading to the rest of the body,” Dr. Selmic explains. “The key is to know which lymph node this is.”
Lasers, Dyes, and Goggles
In this new study, surgeons are injecting the tumors with two fluorescent dyes, called indocyanine green (ICG) and methylene blue. These dyes infiltrate the tumor and then drain into the lymph node. Both dyes are FDA-approved and have been used in human medicine as well for more than 50 years. In surgery, a special laser is used to excite these dyes so they fluoresce, or emit light. This fluorescence can be seen through goggles equipped with a special camera designed to detect these dyes with great precision.
“The surgeon who is wearing these goggles can see which lymph node, or lymph nodes, contain the dyes. This tells us which lymph nodes are draining the tumor,” Dr. Selmic explains. “We remove these specific lymph nodes and send them off to the lab to determine if there is cancer in them.”
“This is a very exciting step because now the surgeons know which lymph nodes to remove for cancer testing. In the past, human and veterinary doctors alike were removing all the lymph nodes in the affected area. Since lymph nodes play an important role in your body’s health, this can lead to complications.”
Technology for Human Medicine
This new method will allow doctors to more accurately monitor for spread of tumors. Doctors will be able to determine if further treatment, such as chemotherapy, is warranted at a given time or if the tumor is still safely localized.
Although the current study involves only dogs, this method will certainly work for cats and other animals.
“This is cutting-edge technology,” Dr. Selmic emphasizes. “It benefits pets significantly and helps doctors understand how the cancer is behaving and how to treat it. The camera is very accurate and eventually, the goal is for this technology to be used in human medicine as well.”
If you are interested in enrolling your dog in the study, contact Rebecca Kamerer at 217-333-5311 for more information.
By Danielle Engel