As an oncologist, I'm always looking for new and effective treatments that will help my patients live longer and healthier lives.
Electrochemotherapy (ECT) is not a new treatment, but it is effective. It's been a bit slow to catch on in veterinary oncology over the past decade. Only recently has the practice begun to pick up, with over 30 veterinary oncologists offering the treatment in the U.S. and one practitioner in Canada.
What are the indications for electrochemotherapy?
The most common indication for ECT is when a tumor is narrowly or incompletely removed, leaving microscopic tumor cells at the surgery site. In this case, a second surgery is always ideal, but sometimes there isn't enough skin available for a successful second surgery. If nothing is done, the tumor could grow back, sometimes as a more aggressive cancer (which we want to avoid). If a second surgery is not possible, our options are usually radiation therapy or electrochemotherapy.
Radiation is an excellent option and is very effective. The downside of radiation is that it typically involves 18 daily treatments, each under a brief period of general anesthesia.
Although there have been fewer studies looking at ECT, studies also show that this is a good option for mast cell tumors and soft tissue sarcomas (amongst others). The benefit of ECT is that there are only two treatments and the cost is usually about half of what radiation therapy costs.
ECT also works well for certain cases of cutaneous (the skin form of) lymphoma, small oral tumors, anal sac adenocarcinoma, cutaneous hemangiosarcoma, and many other types of cancer.
ECT has also been shown to be effective against incompletely resected feline injection site sarcomas and squamous cell carcinoma of the nasal planum in cats.
Just as with any other type of case/cancer, we evaluate each patient individually prior to knowing if a patient would be a good candidate for electrochemotherapy.
What side effects are associated with ECT?
Side effects can be quite variable with ECT. Some patients don't look like they received treatment at all a week afterward, while others have more significant skin side effects.
As with radiation therapy, the skin can appear red, inflamed, ulcerated or scabbed. Sometimes, the second treatment is delayed while we wait for side effects to resolve and for the skin to heal.
Patients undergoing ECT must wear an E-collar throughout treatment until all skin side effects heal. This prevents the skin in the treatment site from becoming damaged and infected from licking.
How does ECT work?
ECT is an outpatient procedure - this means that the patient is dropped off in the morning and goes home later in the afternoon. Patients are either heavily sedated or anesthetized, then they receive an injection of intravenous chemotherapy. We find that this chemotherapy injection is well-tolerated and doesn't tend to cause nausea or other side effects.
The treatment site (which is usually a surgical scar) is then clipped and cleaned in preparation for electroporation. Chemotherapy is then injected into the skin around the scar, which bathes all of the tissues that might be harboring cancer cells. The electroporator's probe (which looks like a tuning fork) is then briefly placed over all areas of the skin (we're usually treating a shaved rectangle of skin) that might be harboring cancer cells. The electroporator delivers electrical pulses to the skin. The pulses cause cell membranes to temporarily become leaky, allowing the chemotherapy that we previously injected into the skin to flow inside the cells and kill them.
I'm very thankful to have had the opportunity to learn this treatment modality. I've been able to help many patients with ECT because frankly, radiation is often financially and logistically out of reach for many clients.
If you think your dog might be a candidate for ECT and you're wondering if you have an ECT practitioner nearby, contact your local oncologist or specialty clinic.
Dr. Lori Cesario
Board Certified Veterinary Oncologist
PS: I'm happy to now offer online oncology consultations. Learn more about how this service can help by visiting the Vet Cancer Consultants site.
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