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

Radiation therapy and dog cancer?

Updated: October 10th, 2018

Radiation is a big gun in dog cancer therapy.  There are many out there that would not even consider it….to hardcore, too scary.  And honestly, many times they might be correct.  But in some cases radiation should be at least considered.

For many it is out of the question.  No nearby cancer referral center, no veterinary university, no money.  But for those that live fairly close to a facility that offers this modality, it is an option.

Why do people opt for radiation for their dogs? What is the point?

Radiation is to help dogs that have cancers that are hard to cure. These cancers either never go away, or go away with treatment only temporarily.  So people consider it as another way to increase their dog’s life expectancy or to hopefully improve life quality.

Radiation is used to decrease the tumor cell burden (kills certain types of cancer cells), in very few cancers can cure them.  More and more frequently, it is used to help with tumor pain. If a tumor cannot be removed with surgery (inoperable), radiation can be an option as well.

What cancers are very sensitive to radiation (where radiation can kill a lot of the cancer cells)? Lymphosarcoma is a biggie, perianal adenoma/adenocarcinoma, neuroblastoma, plasmacytoma, and transmissable venereal tumor.    Some other cancers that are moderately sensitive (radiation helps a bit) are nerve sheath tumors (hemangiopericytomas), fibrosarcomas, and histiocytomas.

Radiation can help control pain with osteosarcomas in dogs.

So that’s a bit of the good.  Let’s look at the bad in the next blog post.

Best to all,

Dr Dressler

Discover the Full Spectrum Approach to Dog Cancer

Leave a Comment

  1. Pearla on October 3, 2012 at 1:52 pm

    Hi Dr. Dressler

    My almost 5 year old American Bulldog was diagnosed with a sarcoma. The pathologists could not commit to which kind but leading towards Osteosarcoma. They found thru a CT scan that she had three areas of concern. Her spleen which they think was the mother ship, the inside of her rib bone and her scapula bone. We had her spleen removed and a biopsy done on her scapula. These were sent to the pathologist for review. Both tumors looks similar but not conclusive on what type of sarcoma it is. Can Osteosarcoma start on the spleen and metastasize to her bones? Or do you think it was the other way around?

    Lots of variables here but figured I would ask what the possibilities are that osteosarcoma can spread from the spleen to the bone.

    She had her first round of radiation today on her scapula because this is the most irritable area for her. She is limping a lot and in some pain.The suregon said there are possibilities that they could remove only a portion of the scapula and avoid amputation. Your thoughts on this?

  2. Gianna Cosme on September 25, 2012 at 9:41 am

    my case is even worst, my 7yo male Yorkie just got diagnosed with a oral malignant melanoma. I live in the Dominican Republic and we don’t have neither a facility or an animal oncologist in the whole island! even the test my vet did had to be sent a US lab, ANTECH Diagnostics in Southhaven, MS. and if you allow me, ill post the results here:

    Microscopic Description:
    Examined are two small sections of oral tissue derived from a single
    wedge speeimen. There is a densely cellular mass of neoplastic
    mesenchymal cells arranged in nests. sheets, and bundles supported by
    afine fibrovascular stroma. Tumor cells are polygonal to elongate.
    wilh small to moderate amounts of amphophllic cytoplasm which Is
    sometimes lightly pigmented, and round lo oval nuclei with
    variably-sized nucleoli. Thers ls modérate anlsocytosls .and
    anisokaryosis. Mitoses are 12 per ten 400x fields. Vascular or
    Iymphatic invasion is not observed. The lesion extends to the borders
    of the examined sections. AII tissue was submitted for processing.
    Microscopic Findings:
    Oral malignant melanoma.
    The mass is a malignant melanoma of the oral tissue. The lesion
    exhibits moderate atypia and mitotio activity. Oral malignant
    melanomas are typically aggressive neoplasms with a poor prognosis.
    and approximately 70% metastasize to regional Iymph nodes, and 67% to
    distant sites, especially the lung. These tumors often exhibit
    invasive growth. and recurrences following surgery are frequent.

    I just want an honest opinion of what to do to at least make it easy for him. Considering the radiotherapy its apparently out of the question, my vet told me that operating on him without the radiotherapy wont be a good thing.

    any meds I should giving him, food, treatment, any advise will be appreciated!


  3. Porkchop bearden on September 14, 2012 at 10:41 am

    Hi. I dont know where to start so I will just throw it all out there.Ok around middle of July we noticed a small cyst like bump on the inner part of our Sharpeis leg. I took a pic of it and sent it to my vet and she just thought it was a fluid filled cyst and said its ok but it will have to be romoved. Two weeks later it tripled in size and I took Porkchop to the vet and she said it needs to come off and we need to set an appt to get it done. So two weeks later we had the surgery done and by then Porkchop had several other cysts forming of all different sizes. Our vet took 2 off and sent them for biopsy and it came back Spindal Cell Sarcoma. Now he is eat up with it on his back leg. I bet there is at least 100 cysts and he is chewing at them and some have gotten pretty big again in just a matter of one week. We dont have alot of money and we dont know what to do. We would like an honest opinion please. I believe amputation is out of the question because it has spread to his groin area right up near his penis shaft and it justs keeps spreading. I was told it was local but I dont understand how it could be local if it has spread all across his back leg and into the groin area. And these are just the places we can see with our eyes! Help please!

  4. Julika Callewaert on August 28, 2012 at 2:50 am

    Dear Dr. Dressler,

    Lela, our 6 year old German Pointer had a tumor on her upper lip removed last week. We just got the pathology result and it is an undifferentiated sarcoma, which wasn’t completely removed. 1 to 3 mitoses per high power field.
    She doesn’t look sick at all and is as sharp as ever.

    Our vet now suggests 2 monthly visits to check whether the tumor reappears.
    But we do not know whether there is metastasis or which grade she has.
    We hope there is more we can do than just sit tight and wait.
    What treatment can we try to give her the best chance possible? Is it even possible to survive this type of cancer?

    Thank you for your answer. We are desperately trying to save our little girl and are trying to locate a vet oncologist, which proofs to be challenging here in South Africa.

  5. Dr. Demian Dressler on July 24, 2012 at 9:26 pm

    Id be thinking chemo like multiple myeloma- pred with melphalan. You can do radiation too- the cyberknife is best. But there’s more!
    Read these too and get your Guide of course.
    I hope this helps!
    Dr D

  6. Monique on July 18, 2012 at 3:19 am

    Dear Dr Dressler

    I have been reading up on Chemotherapy and Radiation for treating cancer in dogs and came across your blogpost. My 11 year old Rottweiler has just been diagnosed with a plasmacytoma. It is on her elbow and has begun to invade the muscle and possibly also the bone, so surgical excision of the tumor is not an option. The recommended treatment is amputation. As she is otherwise extremely healthy, especially for her age, ultimately I am prepared to go this route. However, she is still walking well and appears pain free while on medication so we are managing her conservatively for the time being. I would like to extend the usefulness of the leg for as long as possible with either chemotherapy or radiation or a combination. My hope is that there is an option which can decrease the tumor burden and preserve the function of the joint for a period of time before we need to consider a radical surgery like amputation. Unfortunately there are no nearby facilities for radiation treatment but I am prepared to travel if an oncologist advises that there is a significant possible benefit with this treatment. I will set up a consultation with one as as soon as possible but in the meantime any advice you could offer would be greatly appreciated.

    • Dr. Susan Ettinger on August 10, 2012 at 9:03 am

      HI there Monique,
      I think I can help you on this one. If the plasmacytoma is non-surgical, radaition may be a good option. )I would recommend conventional radiation, not CyberKnife.) Is there a medical oncologist in the area? That’s always a great place to start. You can check out http://www.acvim.org and click on find a specialist. Good luck.
      All my best, Dr Sue

  7. Carol on June 2, 2012 at 6:04 am

    Dear Dr. Dressler,
    Our awesome 6 year old Golden Retriever had a growth on skin with hair, not hairless skin (from what we have been told this makes a big difference) removed from his snout. The lesion started off looking like a very small black tick and when it began growing we had it removed (4mm was the size at removal). The lab report came back saying approx 0-1 mitoses were noted and the the diagnosis was malignant melanoma – left rostral maxilla. There are no visable growths in his mouth. His chest x-ray was clear. After consulting with a canine oncologist, we decided to have more tissue removed the get wider margins and have fluid tested from his lymph nodes. These samples came back from the same lab with no cancer found. My question to you is if this was your dog would do the canine melanoma vaccine? We have pet insurance which will cover half of the initial cost (not sure about the boosters). I’m concerned of the slight risk of it causing his immune system to go in over drive. We put him on a cancer diet. Many thanks,

  8. Lamar on February 16, 2012 at 7:47 pm

    Hi Dr. D,

    Our 8 year old mini schnauzer has been diagnosed with an undifferentiated sarcoma (connective tissue, salivary gland region). We’re close to Colorado State University, took him there, and they suggested that the tumor was inoperable. Local metastasis, nothing distant that we can see. It breaks my heart to give up on him and not provide him with the treatment they suggested (radiation; i think similar to Dr. Ettinger’s machine in NY) but it’s incredibly expensive (approximately $4k for 3 treatments). Prognosis is not great, 50% chance of living a year with treatment, a few weeks to a few months without. We’re depressed, down, and uncertain of what to do. We want to do but what’s best for him (he appears normal right now) so that makes it difficult for us to make a decision. Any other thoughts on prognosis or general feedback? God, I hate this disease 🙁 I’m losing my closest friend I’ve ever had right before my very eyes…

    • Dr. Demian Dressler on February 28, 2012 at 4:42 pm

      Hi Lamar,
      I am sorry to hear this. It is indeed really, really hard.
      Step one: read the Guide.
      Step two: diet. Free download on the top of this page.
      3: apoptogens: i’d combine apocaps with oral neoplasene- get your vet involved, along with high dose iv vit c.
      4: beta glucans: k-9 immunity (old formulation without the flavoring)
      5. consider implating matrix 3 cisplatin beads (not cheap but available from wedgewood pharm online for your vet) for local chemo right in the tumor.
      6. consider low dose (metronomic doses) palladia.
      Have your vet involved in these steps.
      I hope this gets you started in a better direction-
      Dr D

  9. cindy on January 28, 2012 at 7:44 pm

    Dear Dr. Dressler::: On 12/22/11 I took my 6 year old Golden Retriever to the vet because I noticed a lump on her right lower leg.. We were referred to an Oncologist, his results were.. A mass developing in the distal right antebrachial area of the dog.. The mass grew rapidly initially but has stabilized recently. There was also significate swelling of the leg associated with the mass. Antibiotics and analgesics were prescribed which resulted in symptomatic improvement.. Physical Exam Findings ::: Firm to soft subcutaneous mass on the ventral aspect of the distal right antebrachium.. Diagnostic Tests & Results ::::: Thoracic radiograph: No gross evidence of metastatic disease. Fine-Needle Aspiration Cytology of the mass::::: Possible Soft Tissue Sarcoma. Diagnosis:::: Pending histopathology…. Treatment….. Exploration and biopsy of the mass… The mass could not be surgical resected as it was involved with the major flexor tendons and muscles. The mass extended a considerable distant proximally following the major flexor muscle sheaths.. Prognosis.. Pending histopathology…. A biopsy was sent to Michigan State University on 1/18/12, we recieved word from the surgeon that the results MSU had found were it was a benign tumor and wont spread.. Our Oncologist says his results dont come close to the findings of MSU’s results, so he is having it re-tested.. I am so confused with all of this.. Not even 2 weeks ago they were telling us that amputation of the leg was the only option.. Please help with any input you may have…. Thank-you so much….

    • Dr. Demian Dressler on February 8, 2012 at 5:45 pm

      Dear Cindy,
      I am sorry to hear about all of this. Honestly, I would wait for the latest report and let us know what it turns out as.
      Keep us posted as this will be the tie breaker…
      Hang in there-

  10. virginia on December 16, 2011 at 4:55 am

    my dog had a nerve sheath tumor remove a week ago from her elbow, it came back as a stage 1, thank god. She is almost 12 and I am wondering about the benifits, of radiation therpy if she developes nerve pain. So far no real signs, have developed that i can see, can you tell me what to look for.

  11. Sarah on December 15, 2011 at 8:41 am

    Please can someone give advice my 3 year old labrador has been diagnosed with a tumour that is pressing against her spine. We took her to a Vet College who tried to take a biopsy which was not successful. They have told us that they can operate to take a further biopsy but she will be in hospital for at least 2 weeks. We did not want to put her though the stress of a major operation just to diagnose what type of tumour. That will only determine if radiation therapy is an option. She is very healthy other than this. We have now been given steroid tablets for her. We are devasted and feel helpless. We really don’t know what to do for the best as she is so young.

    • Dr. Demian Dressler on December 21, 2011 at 8:28 am

      Dear Sarah
      So sorry, such a young dog!
      I really think you should take some time with the Guide and read through it. I’d be thinking about diet, combination apoptogens, neoplasene, antimetastatics, artemisinin, immune support, and the other steps we have available. Might even consider homeopathy (I don’t push it hard but for central nervous system tumors it might do something)- see this blog: https://www.dogcancerblog.com/blog/homeopathy-for-dog-cancer/
      As always, be sure to have veterinary supervision for these steps
      Dr D

  12. Marina on November 1, 2011 at 3:17 pm

    My 9 year old Newfoundland, Timber, was diagnosed with osteosarcoma 2 weeks ago. I wasted 3 days in shock, in a black hole and in denial, then I very thankfully found your website and e-book. I took her to see a Vet Oncologist for a second opinion. We did chest x-rays which showed nothing, so they recommended a biopsy. They took 4 samples. 5 days later we are told none of the samples showed any cancer but for her age, breed and position of the tumor they still believe it is osteosarcoma, they just didn’t get any of the tumor? I was told they may have to do 2 or 3 biopsies to confirm it – I don’t see the point. She has a little arthritis in her left arm and hips so I have decided against amputation. I think Radiation is our only option at this stage and we are going in two days time for her first session. I have been told that since her tumor was not confirmed by the biopsy they will only do palliative radiation instead of a curative treatment – no academic benefit? I didn’t think radiation was ever attempted as a cure for dogs (am I wrong?) but hearing that they wont consider her for it because they wont get a published paper out of it really ticks me off. Who’s paying for this treatment anyway? sorry for the rant….
    I’m not really sure what to expect from the radiation treatments, will this affect her apetite? burn her skin, shrink the tumor and extend her life expectancy?
    We’ll have to go for it, hope for the best and keep searching for answers. Timber is still enjoying life and I almost gave up on her. Thank you for all of your wonderful information, experience and advice. Thank for starting us off and pointing us in a positive direction. THANK YOU for helping me get my act together. My best friend needs me

  13. Janet C on October 31, 2011 at 4:09 pm

    Dr. Dressler,

    My dog who is 10 years old was diagosed with Hemagtiopercytoma. My vet has removed this tumor twice already and the tumor has returned within a month. it has grown very large in a two month span. My vet has spoken to an oncologist who does not recommend kemo, but suggest radiation be done have my vet debulks this tumor. My dog is in good health other wise. Can you tell me how radiation will help?

  14. Harry A on September 8, 2011 at 10:32 am

    My 15 year old dog had a lump. here is the prognosis…wondering what solution i have as the removal of the lump has caused another problem – the wound has not healed in a month and still bleeds.

    Microscopic Description:
    Left ventral carpus, two punch type specimens: The sections contain a
    neoplastic proliferation of mast cells involving the dermis and subcutis and having a variable eosinophilic infiltrate. The cells are rounded and exhibit mild to moderate pleomorphism with infrequent mitotic figures (0-1/10 hpf). Neither vascular invasion nor lymphatic invasion can be found. All of the submitted tissue has been entirely processed for sectioning.

    Mast cell tumor, Grade II

  15. JON KAY on July 16, 2011 at 7:03 am

    My golden lab is 10 years old and we found out yesterday that
    he has a large tumor in his mouth the size of a golfball and that the cancer is in the very aggressive stage and has spread along the roof of his mouth.

    We were told that conventional surgery is out of the question because of the area where the tumors are. We were told radiation therapy is not available on the Big Island. Can you please let me know where the nearest treatment center
    is closest to the Big Island of Hawaii where our dog can get radiation treatment?
    Also would appreciate your please letting me know whether radiation treatment has been successful in other dogs with mouth cancer?
    Much thanks

    • DemianDressler on July 20, 2011 at 2:50 pm

      Dear Jon,
      One point to consider is what is meant when we say successful with oral tumors. We still don’t have a cure for cancers that cannot be removed with surgery, and so when we say success we are talking about decrease in the signs of the cancer that lasts for some period before returning. The data will vary depending on the type of tumor, which would be needed to determine the best treatment. Biopsy is how we know what kind of cancer we are talking about. Some are more treatable than others. Oral melanoma for example has a vaccine that increases survival times available thought oncologists, although I hear Dr. Leadbetter on Oahu can get it. I would also always consider also diet, apoptogens, immune stimulant supplements, anti-metastatics supplements, and efforts to deliberately improve life quality (these are all discussed in the Guide). For radation, click here and on the landing page to the lower left you will see a link to find radiation facilities you can travel to. Don’t forget hawaii quarantine laws for coming back in the state- talk to your vet about this-. I would read the Guide– it can help a lot too.
      I hope this helps

  16. Catharine Purnell on July 14, 2011 at 3:54 am

    Dr. my dog is 5 years old and just got spayed and had a breast tumor removed. We found out today the tumor was cancer. It is (forgive my spelling) momory cystic carsinoma. The doctor said if she didnt get radiation treatment she will die. I love her and dont want her to die, but there is not way we can afford to have this treatment done. We could hardly afford the surgey. Is there an organization that could help us with the bill? Please e-mail me and let me know. thanks

    • DemianDressler on July 20, 2011 at 3:07 pm

      Dear Catharine,
      the Guide has an extensive list of resources. One would be the Magic Bullet Fund.

  17. Claire Richardson on July 12, 2011 at 8:21 am

    My hound had a lump appear on her snout near her eye. The first Dr took an xray and did a tooth extraction and gave antibiotics. 3 weeks later the second lump appeared and the first lump never disappeared. She then had a CT scan that showed a mass in nasal cavities and brain. Preliminary biopsy results said it wasn’t cancer, just inflammation, but Dr. didn’t believe it and asked they rerun tests. Still waiting for results. She had a mucous discharge from one nostril that was tinged pink with blood 3 weeks after the tooth extraction which is when I noticed the second lump. The doctor gave her 2 kinds of anitbiotics to take. Lumps have not gone away but no more mucous discharge. She has no noticeable weight loss and seems to not have any neurological issues.

  18. Chris on July 11, 2011 at 1:55 pm

    My 11 yr mutt dog was recently diagnosed with a nasal tumor. After getting the initial CT, the mass was extensive but had only minor cribiform plate involvement. There was moderate bone destruction and a visible deformity at the end of her muzzle (about 2cm.) We tried to get a cytology sample and a rhinoscopic biopsy, but they both only caught inflammation. She also have a old mineralized benign/very low grade tumor attached to a couple inches of her GI tract. We decided that if we were going to treat the nasal tumor, we should go in and take the tumor off the GI tract. While in there, the surgeon checked for nodules on the spleen, did a liver biopsy etc. All looked great.
    At the same time, we had the mass scooped out for diagnostic purposes. It came back as an undifferentiated sarcoma, which wasn’t so great. But it had a low mitotic rate. At the same time, the dog hasn’t shown any real symptoms at all until the bump appeared on her nose overnight (I took her to the vet the next day – which she also got amoxocilin for.) Even after the surgery which she recovered amazingly well from, she hasn’t had any nasal discharge. The only symptom she is showing now is some bouts of reverse coughing. Under the circumstances, we decided to go ahead with the definitive radiation of 18 treatments. We’re going to start her on 10mg of prednisone as well to see how she does on that (but we haven’t started it yet.)
    But my question is what was your dogs’ experience with the radiation? She has her same healthy appetite. When she walks and goes to dog park and plays fetch with me – she is super! I can even see in hindsight she had real lethargy and discomfort for about 3-4 months when the tumor was growing and I just took it as regular aging. (I know. I’m an idiot!)
    But this is her second week of radiation – I drop her off at 8 AM, pick her up about 1 and now she just seems SO TIRED! I mean like total bump on a log tired. She slips into that deep REM, running and barking dream sleep in a couple minutes and just sleeps for hours.
    Of course when I pick up a treat or the leash she bolts off the couch. But otherwise its just all deep slumber.
    I have her on the high protein/low carb diet with Omega 3 supplements. This all happened quick, so even though she’s been on grain free for years, we built up to a fatty diet in a pretty quick 3 weeks. Or is she just sick of getting up at 7AM to hang out in the doctor’s office? Is it just cumulative anesthesia?
    No weight loss or vomiting. Good stools. No other “side effects” but she’s just tired all the time in the house. Is this normal? Is this something I should be worried about?
    Anyone have any insight into this? Should I report it to the oncologist?
    Thanks in advance for your help!

    • DemianDressler on July 13, 2011 at 11:23 am

      Dear Chris,
      whenever you are seeing something (like lethargy), that you were not advised may happen as a predictable part of the treatment, it is best to contact your vet or onc. I would suggest this to be safe!

  19. Karen on June 26, 2011 at 1:02 am

    I have a 9 year old mixed (husky/greyhound/shepard/etc) who had a mass discovered on June 20 and had emergency surgery. His spleen was removed and biopsies were done in all lobes of his liver. All his labwork was normal. He has always been an extremely healthy dog until this. The results came back and it was Leiomyosarcoma in the spleen and the liver. The surgeon honestly said he doesn’t know alot about this cancer with possible treatments because he has never seen it before. He is currently recovering from surgery and will get his staples removed July 7. I feel at a loss because it seems there isn’t alot of knowledge/information out there about this. Are there any options for us? Would radiation or chemo help? I would appreciate any information you can give me

  20. Kelley on May 17, 2011 at 9:38 am

    I have an 8.5 year-old, mixed breed, spayed female. She had a mass removed a week ago, and it was STS (Soft Tissue Sarcoma). It was in her elbow joint, so our vet was not able to remove as much healthy tissue as he would have liked to ensure all cells were removed. Her chest x-rays and lymph nodes are clear (phew). We met with an oncologist/radiologist who has recommended 18-22 radiation treatments over the course of the next month. Our regular vet (the one who removed the mass), said if it were his dog, he’d take the wait-and-see approach by watching the site like a hawk and treating it more aggressively if/when it comes back. We want to do as much as we can for her within reason. She has been plagued with many other medical issues during her short life–2 TPLO surgeries on each knee, rattlesnake bite treatment (we almost lost her), a herniated disk, a recessed vulva (chronic UTI/e. coli infections), and elevated kidney values (not full-fledged renal disease quite yet). I’m sure I’m forgetting a few things. We adore her and of course want her around as long as possible, but I am hesitant to put her through radiation if we can hold off and wait to see if there is recurrence. Although, with her luck, I would suspect there will be. Any advice?

    • DemianDressler on May 18, 2011 at 8:44 pm

      Dear Kelly,
      so sorry to hear this bad news. It sounds though like you have chosen the course of action that fits best with your priorities for your dog. There is no “right” way to treat malignancies, thus your inner compass as this is a life quality decision for you, not a medical one. The clinical recommendation from the oncologist is the textbook one, but textbook recommendations are not the determining factor in making decisions such as this one in every case. Guardianship and deciding what your values are are discussed in detail in the Guide, as questions like these are commonplace. I am assuming you have made the dietary adjustments, are supplementing with apoptogens and immune support, and so forth…?
      Dr D

  21. Bill Porter on May 15, 2011 at 5:16 am

    Dr. D
    My 10 yr old Rotweiller has osteosarcoma in both shoulders. She is currently receiving palliative radiation therapy for pain. Can she still have the radiation, and start the Budwig diet (flaxseed oil & cottage cheese)? I want to make sure there is no negative interaction between the 2 methods of fighting the cancer. If there is, how long should I wait after the radiation treatment before starting the Budwig diet?
    Thanks for your input.

  22. Trudy on November 13, 2009 at 4:52 pm

    My Dog has been diagnosed with cancer that is quite aggressive & is being feed a good blood supply.Had him to the U of Minnesota& they said it was a risk to do the surgery because of the blood supply,he could bleed to death!So,now we’re home looking for answers.Why radiation was’nt offered as an option I do’nt know,he’s a 7yr.old mini schnauzer.They told us he’s in very good health.They give him 3wks. to 3months to live.His organs are being compressed because of the tumor located mostly by the kidney bladder colon area. I’m praying & looking for a miracle too.

    • Dr. Dressler on November 29, 2009 at 9:34 pm

      Trudy, did they give you a diagnosis (cancer type)? This can help guide decisions…

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