Small Animal Services: Radiation Oncology

A diagnosis of cancer in pets is increasingly common as our companion animals live longer due to a lifetime of excellent care. Although cancer can occur in pets of any age, there is an increasing risk of most cancers with age. Pet owners should be vigilant about looking for clinical signs that could be related to cancer, such as non-healing wounds, lumps or bumps on the skin or in the mouth, and lameness. It is the task of veterinarians to examine and investigate the underlying cause of such abnormalities. A diagnosis of cancer may come from a blood test, x-rays, or needle aspirates of lesions. Once a pet is diagnosed or suspected of having cancer, a veterinary oncologist is the health professional best trained to further stage and recommend treatments for your pet’s disease.

Typically, cancers may be treated with combinations of surgery, chemotherapy, radiation therapy, and sometimes immunotherapy. In the past, radiation therapy was commonly used to treat cancers that were non-resectable by surgeons or for tumors that were incompletely removed at surgery. Although radiation is still used in this way today, the advent of many new technologies that we now have available at NC State now allows us to consider radiation therapy for cancers that were previously thought to be untreatable, such as large liver tumors or metastatic brain tumors.

We are fortunate to have cutting-edge technology available in the form of a Varian Novalis TX linear accelerator with a Protura six-degrees-of-freedom treatment couch. This allows us to deliver radiation treatments with extreme precision, which results in decreased normal tissue side effects and the ability to increase the radiation dose to the tumor, hopefully improving tumor control. We can deliver radiation via photons or electrons, using both traditional (electron beam and clinical photon radiation plans) and cutting-edge radiation treatment plans (stereotactic radiation therapy (SRT) and intensity-modulated radiation therapy (IMRT)).

Medical Staff hours generally available 7:30am-4:30pm. 

What Makes NC State Radiation Oncology Special?

  • The Radiation Oncology Service cares for more than 200 cases per year.
  • Radiation Oncologist Dr. Tracy Gieger is certified in three medical specialties — Internal Medicine, Medical Oncology and Radiation Oncology.
  • Radiation Oncologist Dr. Mike Nolan, in addition to being board-certified in his specialty, has a Ph.D. in radiation and cancer biology and runs a vigorous research program.
  • NC State’s collaboration with other institutions — such as the Consortium for Canine Comparative Oncology with Duke University — brings top minds together to explore new cancer therapies offering better efficacy and less toxicity for both animals and humans.
  • Despite the rapid change of the increasingly effective technology, we work hard to stay at the cutting edge of what is available in order to provide the most effective treatment, and the highly experienced team employs these tools with great skill and precision.
  • The Radiation Oncology team understands that it is not simply treating animal cancers, it is treating whole families, and approaches client care with this holistic view.

Cancer Types 

Bladder & Prostate Cancer

Does my pet have bladder or prostate cancer?

  • Common symptoms include pain or abnormal posturing during urination, poor urine stream, and/or discolored or bloody urine.
  • Diagnosis of bladder and prostate cancer can be challenging, and may involve a variety of tests, including X-rays, abdominal ultrasound, urinalysis, cytology, biopsy with histopathology, and sometimes even surgery.
  • Almost all bladder tumors in dogs are a type of cancer called “transitional cell carcinoma” (TCC). These tumors grow from the lining of the bladder and/or urethra, and can spread throughout the lower urinary tract.

Information & Resources 

Image of an IMRT plan for a bladder tumor, showing how the high dose of RT (red/orange) is restricted to the bladder, and nearby normal tissues (colon, intestine, etc.) are only exposed to low doses of RT (blue/green.)

Image of an IMRT plan for a bladder tumor, showing how the high dose of RT (red/orange) is restricted to the bladder, and nearby normal tissues (colon, intestine, etc.) are only exposed to low doses of RT (blue/green.)

Bone Cancer

Does my pet have bone cancer (Osteosarcoma)?

  • Osteosarcoma most commonly occurs on the limbs of large breed dogs. But it can occur in any breed, in any location of the body, and at any age.
  • Common symptoms include pain, lameness (limping) and swelling.
  • The diagnosis is often made with X-rays. Sometimes, blood testing, fine needle aspirates and/or biopsies will be used to help confirm the diagnosis, or rule-out diseases that cause similar symptoms.

What is the prognosis?

  • Osteosarcoma is rarely curable. Even if the visible tumor can be effectively treated, this kind of cancer has a high probability of spreading to other parts of the body.
  • Without treatment, bone cancer in dogs is rarely survive more than a month or two. Most dogs are euthanized due to intractable pain or limb fracture.

Information & Resources 


Image from an SRT plan showing treatment (high dose RT in orange/red) of a bone tumor near right the hip.

Brain Tumors

Does my pet have a brain tumor?
Brain tumors commonly cause behavioral changes, gait abnormalities and/or seizures. Some types can cause facial muscles to shrink (trigeminal nerve sheath tumors), while others can cause hormonal imbalance (pituitary tumors).
The diagnosis is often made with an MRI; other tests (CSF taps, biopsies and blood testing) may also be used.
What is the prognosis?
Brain tumors are rarely curable. Without treatment, pets rarely survive more than a few months.
In most cases, the best prognosis is associated with surgery, radiation therapy (RT), or a combination of both.

Information & Resources 

Cardiac Hemangiosarcoma in Dogs

What is cardiac hemangiosarcoma?

Hemangiosarcoma is a cancer of blood vessels. As the tumor grows, abnormally fragile blood vessels are formed, which have the tendency to break open and bleed. This cancer is common in dogs, but rare in people.

Hemangiosarcoma can develop in many different parts of the body, with common sites including the skin, muscle, spleen, liver and heart. Hemangiosarcoma of the heart most commonly affects parts of the heart known as the right atrium and right auricle.

When the tumor is associated with the heart, blood that spills from these irregular vessels becomes trapped between the heart muscle and the fibrous sac that surrounds the heart (called the pericardium) causing compression of the heart’s chambers and subsequently decreased blood flow to the body. This process is known as cardiac tamponade.

Information & Resources 

Chemodectomas (Heart-Base Tumors) in Dogs


  • Cancers of the heart are uncommon, but when they do happen, most occur at a location called the heart-base. Therefore, we call these “heart-base tumors”.
  • There are several types of heart-base tumor, with names like hemangiosarcoma, lymphoma, and chemodectoma (also sometimes called aortic-body tumors, or paragangliomas). Each one can happen in any breed, and at any age, but they tend to happen in middle-aged to older dogs, and:
    • Hemangiosarcoma is most common in larger dogs with relatively long noses, such as Golden Retrievers, Labrador Retrievers, and Doberman Pinschers.
    • Chemodectomas are most common in short-nosed breeds such as Boxers, and Boston Terriers.

Information & Resources 

Feline Acromegaly, Pituitary tumors in Cats


Acromegaly is a syndrome in cats caused by a tumor in the brain (specifically the pituitary gland) that secretes an excess of a hormone (Growth Hormone, GH). The hormone excess leads to development of insulin-resistant diabetes mellitus and enlargement of tissues such as the liver, heart, and jaw.


  • Acromegaly is most commonly seen in older (>10 years old) neutered male cats that have insulin-resistant diabetes mellitus. However, cats of any age or sex can develop acromegaly.
  • Common symptoms associated with insulin resistance include weight loss (despite a good appetite) and increased thirst and urination.

Information & Resources 

MLO in Dogs


  • MLO stands for “multilobular osteochondrosarcoma”. It is also sometimes called multilobular osteochondroma, or multilobular tumor of bone.
  • This is a kind of cancer that starts in the bone.
  • MLO can occur in dogs of any age or breed, but is most commonly seen in middle-aged to older dogs, and is more common in large breed dogs.
  • MLO most commonly grows on the head, including skull bones, and the jaws. It can also occur on in other places, like the ribs.

Information & Resources 

Lung Cancer in Dogs and Cats


  • Compared to people, primary lung cancer is very uncommon in dogs. It is even less common in cats.
  • Most primary lung tumors are a type of cancer called carcinoma. There are various types of carcinoma. Some may have a worse prognosis than others.
  • Common symptoms include difficulty breathing, exercise intolerance, or non-productive cough. However, some dogs only experience weight loss (despite a good appetite) and/or lack of energy. Other dogs have no symptoms at all.
  • Diagnosis of lung cancer usually starts with a chest X-ray.

Information & Resources 

Nasal Cancer

Does my pet have nasal cancer?

  • Nasal cancer is a common cause of nasal discharge, bleeding, excessive sneezing, and several other symptoms in middle-aged to older dogs, and occasionally in cats.
  • The diagnosis is often confirmed using a series of tests, including a CT scan (also called a CAT scan), rhinoscopy and biopsy.

What is the prognosis?

  • Nasal tumors are rarely curable. Without treatment, pets rarely survive more than a couple of months.

Information & Resources 

Client Resources 

Veterinary Surgery

What to Expect

Many patients undergo radiation therapy (RT) on an outpatient basis. Learn more about what the process entails here.  

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Veterinary Surgery

Clinical Studies

Go to the Oncology Clinical Studies page for information on current clinical studies. Details include the study’s purpose, benefits for participating, and financial incentive information.

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Vets Caring for dog

Stereotactic Radiation Therapy

Your veterinary radiation oncologist will be able to help you decide whether radiation therapy can play a role in your pet’s treatment plan, learn more about Stereotactic Radiation Therapy here.  

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Radiating Hope

Follow our board certified Radiation Oncologists and NC State Radiation Oncology service staff for up-to-date news on the latest research, clinical trials, and treatment options available for your pet.

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Read about our Radiation Oncologists and NC State Radiation Oncology service in the news.

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Frequently Asked and Resources

Appointment Guidelines
The Radiation Oncology service is a referral-only service. Once the primary (referring) veterinarian calls and sets up the referral, the owner may call and arrange an appointment. If your veterinarian has confirmed the diagnosis of cancer in your pet, have he or she call our hospital and discuss your pet’s case with the Radiation Oncologist. In some tumor locations, especially for suspected brain tumors, a biopsy diagnosis is not required for consideration of radiation therapy.

At the time of your appointment, the radiation oncologists will discuss the additional tests that are recommended or required prior to radiation treatment, the options and expected outcomes for radiation therapy, and the costs and potential side effects associated with treatment.

Cost Estimates for Radiation Therapy

  • Initial Consultation appointment with the radiation oncology service: $265.50
  • Palliative radiation therapy (typically 1-6 treatments): $750-3000
  • Definitive course of radiation therapy (if no CT scan required; typically 15-19 daily treatments): $4000-5000
  • Course of radiation therapy delivered with intensity-modulated radiation therapy (IMRT) (typically 18-20 daily treatments): $6000-7500
  • Course of stereotactic radiation therapy (SRT) (typically 1-3 treatments delivered over 1-5 weekdays): $5500-6500

When am I going to see a doctor?

Please note that our Interns and Residents (aka House Officers), are fully licensed doctors with the same education and credentials as a general practitioner. There will ALWAYS be a doctor in charge of and supervising all aspects of patient care at the VH. In many cases multiple specialists may consult on a patient should their expertise be required. Typically, a fourth-year student will first collect a detailed history and present this information to the doctor in charge. You will then have an opportunity to discuss things in detail with the doctor and together you and he/she will formulate a diagnostic and treatment plan.

What does it mean to be a ‘teaching hospital’?
In addition to having access to cutting edge diagnostic tools and therapeutic alternatives, the most unique aspect of our facility is that every patient is a learning opportunity for our students. Much of this teaching is done ‘behind the scenes’ as we discuss your pets’ diagnostics and care. What this means to you, the client, is that the process may take somewhat longer than it would at a private veterinarian practice. However, this also means that we have the ability to consult with multiple doctors and a variety of specialists in complex cases.

My doctor introduced him/herself as an Intern or a Resident – what does that mean?
It is important to understand that every intern or resident at the VH is a fully licensed doctor with the same education and credentials as a general practitioner. Interns and residents have chosen to pursue additional, in-depth postgraduate clinical training and were selected by us in a highly competitive international application process. We think you are in great hands!

Is there food and water available for my pet while I wait?
Feel free to ask the front desk for a bowl if you would like to offer water to your pet. However, we do ask that you refrain from feeding your pet. Many procedures require sedation or medication with drugs that could upset your companion’s stomach if there is food present. If your pet must eat for medical reasons (eg. diabetes), please ask the front desk to inform the doctor in charge and make sure they are aware of this first.

I am finished with my visit, why do I have to wait?
One of our goals for our clients is that everyone leaves with detailed discharge instructions. We write our discharge instructions in as detailed manner as possible to help summarize the information covered during the visit and give you specific instructions as to medications, diet, activity restriction, and any other pertinent aspect of care. It may take us some additional time to write these for you; however, this can significantly ease the transition home and back to your regular veterinarian.

You are a State facility, so why are your fees so high?
The VH is a not-for-profit health care center and receives less than 2% of operating costs from the the State of North Carolina. The majority of our operating costs are paid by client fees and donations. In fact, many of the state-of-the-art diagnostic and treatment options we offer are only possible because of generous gifts from our clients. Our fees are set to cover the balance of our operating costs, and we are always looking for ways to provide better service at lower cost. Total costs are comparable to those of veterinarian specialists in private practice.