Things You Need To Know About Radiation for Dog Cancer
ByThis is a continuation of the previous blog topic, radiation therapy in dog cancer.
We looked at some benefits of radiation previously, both in terms of life quality and lifespan.
This time, I would like to look at some of the downsides. I am not interested in painting a darker picture than is necessary. This is a treatment where a rationale approach in needed, where good and bad are evaluated. As an owner and guardian of your dog, you should be advised of things so you can make educated decisions.
Radiation therapy is no joke. Each treatment requires general anesthesia, and protocols for designed for cancer remissions involve multiple treatments each week, sometimes even daily. Multiple rounds of general anesthesia should be taken into account when making a decision about radiation, especially in senior dogs. Most vets would agree that an aged canine and 30 rounds of general anesthesia may not be a good mix.
Palliative treatment, radiation designed for the comfort (pain control) of the dog, is less frequent, perhaps weekly for a month or so. This seems a bit “easier on the system” overall.
The radiation in the beam, if it contacts other living tissue, will damage it as well. Sometimes there is radiation scatter, which is where the beam directed at the tumor actually ends up hitting a bit of normal (non cancerous) body tissue.
There can be some side effects that may be seen immediately following treatment, when the beam contacts normal body parts.
The skin can get a little inflamed, similar to a sunburn. There may be nausea, vomiting, diarrhea, and loss of appetite. If radiation contacts the mouth, irritation and sores may occur within mucus membranes lining the mouth. This can be painful and require care. If the beam or scatter contacts the gland that makes tears to lubricate the eye, injury can occur to the glands. This requires lifetime lubricating ointment to be put in the eyes. Similarly, the lining of the lungs can become damaged if they are exposed to radiation.
All of these effects can occur within days or weeks of radiation treatment and examples of acute toxicity.
Radiation consequences can occur years later…delayed radiation toxicity. This can include injury to kidneys, nerves or spinal cord, and ligament damage.
A bizarre delayed toxicity form is the development of new cancers, as a consequence of the radiation. This is documented with cases of osteosarcoma (bone cancer), bladder tumors, and connective tissue tumors.
Take home message? Radiation is not a minor therapy. Consider it carefully. Be advised if you have a young dog that you are considering radiation for, you may see delayed toxicity, years later but during the dog’s lifespan, even in the form of new cancers.
About the Author
Dr. Demian Dressler, DVM is known as the "dog cancer vet" and is author of Dog Cancer Survival Guide: Beyond Surgery, Chemotherapy & Radiation. Visit his blog and sign up free to get the latest information about canine cancer. Go to http://DogCancerBlog.com.
19 Comments
November 25th, 2008 at 12:38 pm
I wish we would have known more about the effects of the radition toxicity and other complications. It would have saved us I think a lot of heart ache. We had a chocolate lab that had an osteosarcoma on the spinal cord. We went through the 4 weeks of daily radiation treatments. Had wonderful results. A dog who could barely walk and squat to potty came out to where she could run, jump and play again. It was a godsend to us. Then two weeks home and the day before her second chemo treatment she suddenly lost all motor function in the rearend again and lost bowel movement. It was heartsickening. It was due to radition toxity. It killed the spinal cord. Our hopes of recovery were dashed.
November 25th, 2008 at 5:15 pm
I’m sorry that Carrie had a negative experience with radiation with her Lab.
However, there is always good and bad results with anything in life.
I think the advise in the Blog was good……… know the possible consequences and make decisions based on that information. We had a 13 years old boy who, with a combination of radiation and surgery, outlived oral melanona for over
a year. His demise was simply an old boy whose body literally gave out.
Oral cancer did not kill him.
November 27th, 2008 at 11:45 am
Candy is now 14.5 years old. At age 7 she had about 4 radiation treatments for a plasmacytoma on her palate. I never thought she would live this long. She now has another cancer, coincidentally in the mouth–mycosis fungoides or Cutaneous T cell lymphoma. I feel that she is a success story though with the radiation. Maybe she has this cancer secondarily to the radiation but I cannot complain. I don’t think it would be advisable at her age now but in hindsight, I was glad she had it then. The weird thing was that she got this cancer after some acupuncture and I had read somewhere that it “could” activate a cancer in remission. I regret doing it but all the vets said it wasn’t a problem. We should listen to our gut instincts. The acupuncture “stimulated” her immune system. In lymphoma, you don’t want the immune system stimulated. She got sick after the first treatment and after the second she urinated a day later in the house (she doesn’t usually do that. I am not an acupuncture fan at all.
Lilly
November 30th, 2008 at 5:22 pm
I have mixed feelings going into the need to make a decision of what to do next …we had the mast removed and now need to have the consult for what to do next. Our vet recommends chemo/radiation to give us more time w/our dear friend. As opposed to how much time w/out treatment. I appreciate the blog which shares w/us some idea what can happen after treatment and of what questions to ask going into the consult. This is difficult not only emotionally but financially. Blessing to the blogs participants
November 30th, 2008 at 5:26 pm
does anyone have the absolute on hemangiosarcoma? my dogs mast was on the left chest outside the ribcage. I am unclear before our next consult as to the malignancy having been derived from the vascular endothelial cells. I am guessing that something bad invaded the dogs body broke down the immune system and developed this mast (we just had removed). thanks for any input
December 12th, 2008 at 7:52 am
I have a 12 year old Italian Greyhound. He started having resperatory problems 6 months ago. Was diagnosed with Pnuemonia and put on antibiotics which really seemed to help. He want off the antiobiotics and starting having sinus problems. Went back on and they got a little better although didn’t clear up. As time went on, his sinus congestion continued to get worse. We took him to a specialist who did an MRI and biopsy and the initial reading showed no tumors and biopsy was negative. Also no infection was found. The MRI was re-read at a university and they said they saw something which looked like a tumor mass, but very far back in the nasal cavity. When our doctor questioned them, they said on second review, it could have just been shadowing. Now the specialist wants us to take him to the university for another biopsy and is leaning toward a cancer diagnosis. Other than some days having pretty sever nasal congestion (breaths out of his mouth), he is fine, happy, has a huge appetite, etc. At 12 years old and the postiion of the “potential” tumor I wouldn’t put him through radiation. Is it worth doing anymore tests to confirm or rule out Cancer? I just feel that they are missing something here. Maybe some type of infection that is not showing up on the culture.
December 14th, 2008 at 10:31 pm
Jeff,
make sure they did a nasal culture (bacterial and fungal) of a nasal wash using a polypropaline urinary catheter or the like bent at the tip and introduced above the soft palate (entering via the mouth) to flush sterile fluids back through the sinus for collection as it comes out of the nostrils. You can have a cytology done at the same time. This is a nice high yield procedure.
The logic here is that you can do something with the information (new antibiotic or antifungal).
If you are not going to have radiation done, there is little point in getting another biopsy. The nasal sinus flush is not invasive or painful and the information has some practical application.
Don’t forget about tooth root abcess, another treatable problem that might present like this.
Best to your IG!!
D
February 5th, 2009 at 7:36 am
Dr Dressler,
We are dealing with a soft tissue sarcoma in our 12 yr old shepherd’s shoulder. The options given by the oncologist are radiation or amputation. She is scheduled for amputation this coming monday. I dont think we can afford radiation and I know we cant afford multiple rounds of it. Do you know anything about radiation causing a breakdown of the immune system? Statistically, how likely are complications from radiation?
February 6th, 2009 at 1:44 pm
Thanks Dr. Dressler for this excellent information. It’s a lot to think about in making our decisions, but I feel better about being able to make a good decision.
February 8th, 2009 at 11:06 pm
You are welcome!
February 8th, 2009 at 11:20 pm
Karen, there is an 11% complication rate for fracture of the humerus and/or bone cancer from the radiation. I do not have stats for the more minor side effects or toxicities, and they also depend on the doses used. Talk to the oncologist. Yes, radiation could cause bone marrow suppression (immune compromise) but it usually goes away.
D
February 11th, 2009 at 9:00 am
Does anyone have any information on treating squamous cell carcinoma of the nasal planum? My sheltie has been diagnosed with it. It has spread to the lymph nodes. I have taken him to an integrative vet for intravenous megadoses of Vitamin C and then will follow up with immune booster shots and oral Vitamin C. Radiation not an option. Has anyone had success with this or are there any other options? He is 7 years old.
February 14th, 2009 at 10:36 am
On the positive side, I have a 12 year old rescue terrier mix who was diagnosed with nasal adenocarcinoma in August of ‘06. Literature at that time recommended radiation with limited results. When I went for a consult with a well known oncologist/radiologist, he recommended surgery and radiation due to new statistics gained using newer radiation equipment. The tumor was still well enclosed in the sinus. I decided to be agressive and almost 21/2 years later he is still here. He has lost sight in one eye and did have a bad initial reaction to radiation for about 10 days. He also had a delayed reaction (we think) one year later with severe eye pain which was treated with prednisone and is now gone. At that time it was discovered that the tumor had returned and it is progressing but slowly. Metacam has helped to hold it at bay for 8 months. I do use lubricating drops as well as other supplements. He is happy and still loves to walk/run.
March 26th, 2009 at 4:30 am
Dr. Dressler:
My almost 9 year old Cocker Spaniel/English Springer mix has been diagnosed with extramedullary plasmacytomas. She has a good sized oral tumor and then numerous small cutaneous tumors. The tumors are benign, but because they are behaving more “aggressively” (systemic vs isolated) then the oncologists are recommending a combined chemo and radiation treatment. We started her on vincristine yesterday and will be doing a vincristine/cyclophosphamide treatment. The radiation oncologists are recommending that we treat her oral tumor with radiation. I am trying to determine the side effects of this treatment and whether we should proceed with it, or just wait and see what the chemo does for the oral tumor. Since plasmacytomas are very responsive to radiation, it seems like it would “work” in shrinking the tumor — but it means that she will be exposed to repeated anesthesia over 6 weeks, and the tumor is close to her eye. Not to mention, it is very expensive (although we would certainly do it if that is what she needs). Any thoughts on the costs/benefits of proceeding solely with chemo for now? I realize that it is partly dependent on whether she is responsive to the chemo.
Thank you! And thank you for this wonderful blog — I have already found a lot of answers to my questions.
July 4th, 2009 at 9:44 am
My mom has a 13 year old min. schnauzer that was recently diagnosed with a nerve sheath tumor. They removed it and sent her to purdue university animal hospital to see what options they had. They gave my mother two options. She could do a definative radiation therapy mon- fri for a month for a “cure” or wait until another tumor shows up and then do palliative radiation once a week for 4 weeks. We have only about 1 to 2 weeks to make our decision. There seems to be so many pros and cons with each treatment. I believe her age is the major factor. I do not want her to go through that intensive radiation and her body starts a downward spiral because of her age and then shortens her life, but I also do not know when or if the tumor will come back. She had a intermediate diagnosis on the previous tumor and the vet seems to think it will return, the question is when. My thoughts are that she could just wait to have the palliative radiation and possibly live out the same amount of time because of her age. But what if she could live to be 17 or older and we choose the wrong path? Can you give any advice as to your feelings on her age and which direction would be in her best interest. We are very confused about what to do. Thanks, this site has been very helpful.
February 3rd, 2010 at 8:20 am
how do i know if my dog has cancer of the nasal planum and do you know any web sights that have pics of dogs with it?
thanks
February 5th, 2010 at 9:41 am
Our dog was diagnosed with Stage V a Lymphosarcoma 9/28/98 (Chemo started 9/29/09). She has completed chemo at MSU Vet School and went into remission within the first two weeks. We have a consultation in a week to discuss a recommended radiation program to prolong her remission. I believe it is a 1/2 body at a time treatment at a low dose level of radiation. It is not a long term radiation program. I don’t see this type of radiation program discussed in Dr. Dressler’s book. Have any of you been through this type of program and if so what were the side effects?
Thank you,
Bobby Bidwell
February 5th, 2010 at 12:13 pm
Dr. Dressler,
Dr. Dressler,
I didn’t realize these comments/questions were going to you directly. Please read above email comment about radiation. I have read where the combination of chemo and 1/2 1/2 body radiation can increase Lymphoma remission up to 2 years or more. I can’t remember the book but I read it at the book store and it was Complete Guide to Canine Health (I think it was something like that). It was a huge technical book. I was looking up supplement information.
Bobby Bidwell
February 7th, 2010 at 9:11 pm
Dear Miranda,
I assume you have had a veterinary examination for this problem, right? Sadly, most lesions require a biopsy for diagnosing cancer, in spite of how they look to the naked eye. Here is a link so you can see what is involved in this:
http://www.youtube.com/watch?v=nmcxG8TIvQw&feature=related
I hope this helps,
Dr D