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Featuring Demian Dressler, DVM and Sue Ettinger, DVM, Dip. ACVIM (Oncology), authors of The Dog Cancer Survival Guide

CyberKnife RadioSurgery in Pets

Updated: December 18th, 2018

If you have been following me on Facebook at Dr. Sue Cancer Vet, you know that last week I was lecturing with what I call “ASC Team CyberKnife.” This team includes radiation oncologist Dr. Sarah Charney, neurologists Drs. Rick Joseph and Jason Berg, and me, the medical oncologist.  We manage all the CyberKnife patients that come to the Animal Specialty Center (ASC) in Yonkers NY.

So after work on two nights, we all traveled to Red Bank, NJ and then to Norwalk, CT to talk to veterinarians about CyberKnife RadioSurgery, what tumors it’s good for, and our experience over the last 4 years.

There is a lot of great information on radiation therapy in the Dog Cancer Survival Guide, but in case you haven’t read it yet, you should know that typically, radiation therapy is used for local disease control — to damage and ultimately kill the primary cancer, usually as a follow up treatment to surgery. For example, if a dog has an incomplete resection — which means that there are cancer cells detected in their surgical scar on the biopsy report (dirty margins) — we would follow the surgery with radiation treatments to “clean up” those microscopic cancer cells. This is pretty common when it comes to a mast cell tumor or a soft tissue sarcoma. These conventional radiation therapy treatments usually require fifteen to twenty treatments, which are also called fractions (see below). Each session requires a short anesthesia, and pets are usually treated daily Monday to Friday with the weekends off. That’s a lot of anesthesia.

Why SO many treatments? It’s all about the normal tissue in the radiation field.  To minimize damage to the normal cells, the dose is divided up into many small treatments. These “fractions” are helpful because normal cells can repair themselves more efficiently after smaller, multiple doses. For example, if your dog has a tumor in the nose, conventional radiation therapy will probably expose other nearby body parts to the harmful radiation: the mouth, eyes, and brain may get radiation because it is in the treatment field.

It’s this damage to otherwise healthy tissue that has motivated oncologists to look for a way to deliver radiation with more precision, fewer side effects, and fewer treatment sessions.  The new technique called radiosurgery aims at getting the radiation energy directly to the tumor – even inoperable tumors – while avoiding healthy body parts that might be damaged by the beam or by its scatter.

By the way, I personally think the radiosurgery name is silly because there is no surgery in radiosurgery. There is no actual cutting – the name is meant to imply that radiation is accomplishing what surgery would do if it could actually get to the tumor.

Radiosurgery is not good for every type of tumor (for example, mast cell tumors and soft tissue sarcomas are not good candidates). But it does offer hope to some patients whose tumors were once considered inoperable. Here’s why:

The new, modified linear accelerators (radiation therapy machines) can generate very controlled, narrow beams that deliver radiation very precisely. The machine has five “arms” and rotates around several axes. It can approach a tumor from almost any angle the radiation oncologist wants it to, and while a traditional linear accelerator has two to four ports (holes where the radiation exits), the CyberKnife has hundreds.

Planning the radiation is critical when you’re dealing with radiosurgery. First, a CT (computed tomography) scan is done to get a very detailed three-dimensional image of the tumor. (For brain tumors we need both a CT and MRI for planning.) Then, Dr. Charney, our radiation oncologist, uses a complex computer program to plan precise coordinates for the radiation beam.

The precision involved in radiosurgery is amazing, and it also makes radiation therapy more appealing to dog lovers. For example, a nasal tumor that requires fifteen to twenty conventional sessions and exposes the mouth, eyes, and brain to radiation can be treated in only three consecutive CyberKnife sessions. That’s five times less anesthesia, five times fewer trips to the hospital, and fewer side effects. And the results are comparable to traditional radiation therapy. Some brain tumors are treated in just one treatment. It is pretty amazing!

My practice was the first to offer CyberKnife Radiosurgery to animals, and we have been treating dogs and cats since March 2008. Currently, radiosurgery is only practiced at the University of Florida, Colorado State University, southern California, and my practice the Animal Specialty Center in New York.

In my next blog I will tell you what tumors we treat and our experience so far. Stay tuned – this is pretty exciting stuff!

Leave a Comment





  1. […] turned out to be a life saver! The one option that the teaching hospital could not offer was cyber knife treatment – targeted intense radiation – which was available through Hope Veterinary Specialists […]

  2. They want EFX on April 12, 2016 at 1:28 am

    What is the real cost of Cyberknife treatment? I have an 11 year old Scottie with Prostate and Bladder cancer. I was told 10k all in for about 8 months of life. The NC State study said 5.5k. I was just wondering… has anyone had 2-3 treatments with a CT scan and what was the cost?

    • Ellen Schlegel on December 11, 2018 at 6:21 pm

      For us it is $13 K in California( Cyberknife alone that includes placing the markers under a CT scan for the actual treatment, and it doesn’t include all the diagnostics prior. )

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    […] State University, southern California, and my practice the Animal Specialty Center in New York. CyberKnife RadioSurgery in Pets – Dog Cancer Blog […]

  4. My love bug Bella has cancer - Page 25 - Golden Retrievers : Golden Retriever Dog Forums on February 26, 2016 at 8:08 pm

    […] on the dog, there are fewer side affects, the treatment is more targeted and a lot less expensive. CyberKnife RadioSurgery in Pets – Dog Cancer Blog […]

  5. […] the prostate tumor pressing on his colon. His owners had come to me to consider a procedure called CyberKnife, a precise radiation of the […]

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    […] The Stereotactic Radiosurgery is a fairly new procedure. It has been used in humans for many years, but only in the last 5-6 […]

  8. Susan Kazara Harper on November 16, 2014 at 9:13 pm

    Kim, What did the MRI show? It’s not productive to pull stats out of the internet, as your dog is his own, beautiful, individual being. If you have any more info, do let us know and we’ll be glad to help untangle things, but of course your vet is right there with the results and the offer of treatment. An on site expert. Make sure your boy’s nutrition is a clean and natural as you can get it to support him.

  9. Kim on November 8, 2014 at 12:46 pm

    My 6 year old Rhodesian Ridgeback had cyberknife surgery on a femoral nerve root tumor last Oct. he is now showing the same symptoms again? I am having a MRI on him on Monday. What are the percentages than it could possibly reappeared? Also does scar tissue occur after Cyberknife? It just seemed like one day he was fine then he turned in my SUV and let out a loud yelp and since then hasn’t put his leg down, holding it up to walk? We had a X-ray and his legs and hips are great! Is is at all possible he could have torn scar tissue??? I know I’m pulling at straws! Thank you any insight would greatly appreciated. Thanks Kim from Anchorage AK.

  10. robert lahser on June 6, 2013 at 2:32 pm

    Hello- can you please please please give me a ball park price for Cyber Knife to treat a 1/4 marble sized mostly exposed Mast Cancer tumor on our 12 -year-old dog Murphy’s right flank. It’s a third re-curring MCT ,Murphy has had three surgeries over the past 28 months and is currently on Kinavet,a new MCT lump popped up a week ago and the Kinavet is not working. We are seeing an Onco in Matthews,NC and the best option for survival that we were given is 16 radiation treatments at $5k plus surgery. All three recurring MCT’s have popped in the same spot. Today 6/6/13 I called Vet Speciality Clinic in Yonkers and was told I would have to pay the $175 consult fee to get a cost on the Cyber Knife treatments. We are spending more than we can afford now on Murphy’s treatments. Can you please let me know a ball park price on Cyber Knife,you can email me privately. Many thanks,Robert in N.C.

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