CyberKnife RadioSurgery in Pets
Sue Ettinger, DVM. Dip. ACVIM (Oncology). Dr. Sue is a boarded veterinary medical cancer specialist. As a Diplomate of the American College of Veterinary Internal Medicine (Oncology), she is one of approximately 400 board-certified veterinary specialists in medical oncology in North America. She is a book author, radio co-host, and an advocate of early cancer detection and raising cancer awareness. Along with Dr. Demian Dressler, Dr. Sue is the co-author of The Dog Cancer Survival Guide: Full Spectrum Treatments to Optimize Your Dog’s Life Quality and Longevity.
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!
Sue Ettinger, DVM. Dip. ACVIM (Oncology). Dr. Sue is a boarded veterinary medical cancer specialist. As a Diplomate of the American College of Veterinary Internal Medicine (Oncology), she is one of approximately 400 board-certified veterinary specialists in medical oncology in North America. She is a book author, radio co-host, and an advocate of early cancer detection and raising cancer awareness. Along with Dr. Demian Dressler, Dr. Sue is the co-author of The Dog Cancer Survival Guide: Full Spectrum Treatments to Optimize Your Dog’s Life Quality and Longevity.
I made a typo it was a 20 minute swim not 20 hours! Before the event. (i.e. He was not preparing to swin the English Channel)
Our 12 year old mixed breed short haired terrier who weights about 40Lbs was diagnosed with a 1CM X .5 CM left side trigeminal nerve sheath tumor by MRI that had not traveled into the brain. He was then put on 10 Mg.of Prednezone in anticipation of Cyberknife at UC Davis Veterinary Medical Center under the direction of its chief of that Department Dr Theon which he had on October 23, 2012. He tolerated the procedure well and we drove him home to Seattle a weak later and was then slowly weened off the Prednezone gradually over the next few months until he was down to 2.5 Mg every 3 days. in February. We were advised by Dr. Theon it would be safe for him to fly to our winter home in Arizona in January while he was still on that dose, but we waited until February when he’d had his last dose. He seemed fine after the flight and he’d been off Prednezone totally for about 5 days. However shortly after (after one brief 20 hour swim in the pool — he’s usually good for an hour or more), he developed a marked weakness in his right side became disoriented and could barely keep his feet from sliding out when standing on tile floors, and could only walk with the assistance of leaning on a wall and began running into open door on the right. All this happened over the course of an afternoon. We rushed him to the Arizona Veterinary Hospital in Tucson where under Dr. Theon’s telephonic direction he was administered 15 Mg. Prednezone and that was continued for the next month. For the better part of that month he could hardly get out of bed to toilet (but he generally could he had only a couple of urine incidents when we weren’t paying attention — although he’d never done that before). His bowl movements were generally OK though and he was always hungry. Slowly he got so where he could walk again without use of walls but pulling to the right and finally in a straight line if he had the edge of the sidewalk to follow and walking over a mile. But on that heavy dose of Prednezone he had significant muscle wasting (and was ravenous all the time). Finally Dr. Theon decided the Prednezone was doing more harm than good and he reduced it to 10 and began weening him off again. He is now down to 2.5 daily and starting to gain a little muscle. He has however lost vision in his right eye (we are told permannetly) , it doesn’t tear properly and he has little sensation on the right side of his face and drops food when he eats from that side. But otherwise he’s walking, eating and toileting OK. He also has water therapy every day on an underwater treadmill. There was much speculation between his Oncologist in Tuscon, his Neurologist in Seattle and Dr. Theon at UC Davis as to just what occurred and in the absence of another MRI they can’t tell (and all say they might not treat differently if they did). The opinions ranged from a bleed caused by the void created by the Cyber knife that got into the brain, or an inflamation occasioned by his body attacking the dead cancer cells (and cutting off the Prednezone too soon), an unrelated stroke, or and everyone says this is highly remote a return of the cancer? Now Dr. Theon and the Neurologist say they would like to do another MRI to determine what the cause was although they say we might trying increasing the Prednezone first and seeing if he improves on that? The Oncologist in Tucson said that the University of Colorado has some sort of study that supports keeping them on Prednezone for 6-12 months is necessary to prevent dead cancer cell inflamation (she studied at U of Colorado but frankly seemed the least knowledgeable due to her youth). we only kept him on for four before his “stoke” or what ever you want to call it? There is a risk of loosing him in the anesthesia if we re-image him. But despite his muscle loss from the Prednezone his neurologist thinks he’s strong enough to survive it. WE’d like to get him off the prednezone as high doses really alter his personality and all doses even the 2.5 daily now do some and causes muscle wasting and we are concerned about permanent damage to his stomach (although he takes it with a pill to coat his stomach before hand). Is there a Colorado Study? How long do your keep dogs with this type of cancer on Prednezone after cyber knife? Should we re-image and what would that tell? And what could we do different depending on what they found? Dr. Theon said he’s not a good candidate for another Cyber knife treatment if the cancer returned. We are very worried? But he is much better than he was in February. But not what he was. If his personality returned when he got of Prednezone that would be a beautiful thing. But we are prepared to “go slow” and prolong his life. He was a very loving dog before but the heavy does of Prednezone makes him very hyper, fearful and a little mean less at 2.5 but still not the same dog. His name is Phinney!
My girl “Mushi” has a 2cm right brain stem, possible Trigeminal Nerve Sheath Tumor and had Cyberknife 4 1/2 months ago.
Within the past few weeks, we are seeing the same signs return that she had prior to CyberKnife treatments…. feet slipping when walking, difficulty getting up and down and the inseccent circling to the right(the side of the tumor).
She seemed to have improvement signs following the first CyberKnife treatment, but unfortunately was not able to be weaned off the prednisone (5mg 2x/day).
She has experienced a couple episodes of post-therapy swelling that can occur that requires a five days course of increased prednisone to 5mg/AM and 10mg/PM) to resolve the swelling/pressure.
Your experience and timeframe of symptoms seems to coincide with ours.
We have not undergone a post CyberKnife MRI to check to tumor size/status.
I would appreciate any details you could provide as to your experience after this post.
Did you have a follow up MRI? If so, what did it reveal?
Did they offer another course of CyberKnife treatments? We were advised by our radiation oncologist that it could be repeated in January( if needed). Her original treatment ended 8/23/2018.
I hope that your pup did well after this episode.
Thank you for your time and info. It’s greatly appreciated and desperately needed.
Dr. Ettinger
Our 8 yr old Boston Terrier is presently with a pituitary macroadanoma approx
8mm. one week ago we took her to the Emergency Hospital with excessive panting of sudden onset. The staff performed a comprehensive work up.
(Several chest & neck xrays, scope of throat, us of abdomen, several CT’s of
neck and head and blood work) Cushings Disease and C6 vertebral herniation were diagnosed. We decided to have decompression of the disk per the recommendation of the surgeon. Her panting was not relieved so a second surgery was performed. The Surgeon was not able to remove all of the disc material on the first and second surgery. She remained to pant excessively. It was then decided to perform a contrast CT and it revealed the macroadanoma. Seven days later we are at home. She was prescribed a fentanyl patch, tramadol, gabapentin & pednisone. She does very well with anesthesia, going under 5 times in seven days (she had her palate resected two years ago). She only has subtle neurochanges – nothing dramatic except for the excessive panting.
We are interested in Cyberknife radiation, but cost is a concern because of
recent treatment amounts. Could you provide an approximate cost range? Also, how many treatments are typical for a Pituitary Macroadenoma? – speculatively. We live in Texas. We plan to see a general vet on Monday to address the Cushing medication needs. We would also like to have the first radiation treatment next week if possible. Who should provide the referral the surgeon who did the CT or our regular vet?
Thank you for your time, Wendy Finch
Wendy,
Please contact Dr Joseph and the Neurology Service at my practice tomorrow. 914-457-4000
Pituitary Macroadenomas come in through Neuro, and they will be able to give you all the info.
For those traveling to NY, planning would be Monday and treatment later that week. Some neuro cases are 1 treatment, some are 3 (Wed to Friday)
All my best, Dr Sue
Aloha Dr. Ettinger,
Our 7.5 year old Cairn Terrier, Bonnie, was just diagnosed with oral squamous cell on the maxilla during a dental clean. Our Vet removed 2 teeth, but referred us to an internal medicine specialist (not a Board Certified Oncologist–apparently none in Honolulu) for further treatment. After reading your section in the Dog Cancer Survivor Guide, we believe that radiation therapy, preferably Cyberknife, is the one of the best treatments for this type of cancer and its location, but in Hawaii there is no radiation therapy option for pets.
We will consider taking Bonnie to the mainland for Cyberknife treatment, but would like to understand how many treatments are typically involved for this type of surgery and what the typical period is between Cyberknife treatments.
Thanks in advance for any advice you can offer.
John
John,
Thanks for your interest in CyberKnife. If you are still interested, please call mu hospital tomorrow/this week. One of my nurses will give you an overview. Typically my radiation oncologist will then talk to cases that are traveling so far prior to your trip. While we would be happy to help in NY, there is also radiosurgery at CSU (Colorado State) if you think that is easier. Again, we are happy to help. Our # is 914-457-4000.
Aloha, Dr Sue
Hello Dr. Ettinger,
My 8 year old spayed female Rottweiler, Abigail was diagnosed with Brain Cancer on the overnight of December 21st, after having a seizure
I took her to GSVS in Red Bank, NJ, where they did tests and an MRI, which showed the brain cancer. I was told it was 2x3x2 CN and it was right sided. They also mentioned “old factory lobe”, which I have no idea what that is. Was also told that it was aggressive and had already eaten so e of the bone.
Abigail is not and has never acted any differently than she has her whole life.
Would appreciate and be ever so grateful for any and all information.
Do you think cyberknife would help her?
Currently, she’s only on Phenobarbital (90 mg twice a day). She weighs approximately 104 lbs.
Thanking you in advance,
Elinore.
Hi Elinore,
Sorry to hear about Abigail and her brain tumor. She may be a candidate for CyberKnife. Patients with brain tumors come in through the Neuro Service (not my Medical Oncology Service), so if you are interested, you can call 914-457-4000 to make an appointment. One of the neurology nurses can answer some basic questions on logistics, etc. We are in Yonkers NY so not too far from Red Bank. You can check our our web site too!
Good luck to you and Abigail.
Dr Sue
Hi-
I wanted to check in because I posted on this article 6-27-12. Our dog Owen has an inoperable liver tumor…it is right-lobed and is pushing on the vena cava. UW-Madison vet tried to remove it but because of the size (16cm) and location, Owen likely wouldn’t have survived the surgery. We looked into all of his options including the cyber knife at Colorado State U and Dr. LaRue looked over his scans but said the procedure would be too damaging to his other organs. We then took him for a study in NYC at AMC where they performed a Transarterial Chemoembolization. That was done in July and only shrunk his tumor by a very small amount. The tumor has now grown a little but we will be checking him to see if Palladia is helping keep the tumor from growing too fast. He is in fabulous heath otherwise–eating great, tons of energy and most of all happy! We will take however long we have with him and we know that even though this procedure didn’t shrink his tumor a lot, it has made a huge difference in how he feels. Other candidates have had the tumor shrink enough to surgically remove. So that is another option for liver cancer.
I have been told that my dog, rufus has a brain tumor, I have a CT scan appointment for Tuesday August 14th at blue pearl. Do you know of anywhere in Minnesota where they perform cyberknife?
Hi Larri,
Sorry about Rufus. No, CyberKnife is still pretty uncommon. If travel is an option, you could come to my practice in NY or Colorado State U also preforms stereotactic radiosurgery.
All my best, Dr Sue
Dr. Ettinger,
My dog Roxy had Cyberknife in February of this year. She is having a tough time with what is described as a late effect brain injury most likely caused by the cyberknife. When I heard about cyberknife I never found any articles that mentioned that things can go wrong. I know of other dogs that have had the cyberknife and have had issues too. How do you address this? I was hoping for 16 months with my dog and now it seems that if we make it to 6 we will be lucky.
You can read Roxy’s blog at: http://roxycyberknifebraintumor.blogspot.com/
“Late side effects, which are rare, occur months or years following treatment and are often permanent. They include:
brain changes
spinal cord changes
lung changes
kidney changes
colon and rectal changes
infertility
joint changes
lymphedema
mouth changes
secondary cancer
fracture of bones”
Hi Anne,
I am sorry Roxy did not do as well as expected. There are always dogs that happily do better than the statistics and some that sadly do worse. When I do a consultation for a potential CyberKnife (CK) case, myself and the radiation oncologist always review the specific side effects based on where the tumor is located and where we are radiating. Unfortunately there are still side effects with CK and they will vary case by case. In general the side effects are much less severe than they would be with connventional radiation.
As for the list of side effects you posted, they too will vary with the tumor. Clearly if you are radiating near the colon, it may have side effects, but you won’t have this with nasal CK. That’s why a one on one consultation with a specialist is so important.
I am simply trying to educate Guardians about CK so they know it MAY be an option for some cases.
Again sorry about Roxy’s results. While I do not know her case personally, I know it is heartbreaking.
All my best, Dr Sue
Dr. Ettinger, we have been told that our 10 yo Wheaten Terrier (Zoey) has an inoperable menengioma on the brain stem. We met today with the Oncologist (Dr. Feinmehl) at Veterinary Specialty Center in Buffalo Grove, Illinois. We were shown the MRI visualizing the tumor. Dr. Feinmehl indicated that radiation therapy might give Zoey 1-2 years more with us and that Cyberknife might give her 2-3 years. We are very concerned about Zoey’s quality of life post procedure. I think Dr. Feinmehl is contacting your program on our behalf.
Hi Greg,
Sorry to hear about Zoey, but I am glad you know about CyberKnife! Brain tumor cases come in thru Neuro Department for CyberKnife, so your vet would be speaking to Dr Joseph or Dr Berg. Were they able to contact them? If not email me through my website and I can try to help.
All my best, Dr Sue
Thanks Dr. Ettinger. You’re correct that what was used at WSU was a gas anasthetic, specifically desflourane (which I’m guessing is related to sevoflourane). I’ll have to see if the clinic with whom I’m currently in consultation can use it if we go ahead with the UGELAB procedure, assuming it is a strong enough anasthetic for the procedure.
You’re also correct that it was stereotactic radiosurgery which the specialist with whom I discussed this said that it was not, unfortunately, an option for bladder TCC, as you noted. However, you also mentioned that it can be used for urethral tumors. Does that mean that this could be a palliative procedure for my girl’s TCC that has spread to her urethra?
Thanks.
Hi Chris,
Glad you have been getting more info that is helping answer your questions. CyberKnife can be used for the urethra, but remind me, is she getting conventional radiation to the bladder?
Dr Sue