Cat about to be examined in clinic by veterinarians

Oncology

When a pet is suspected of having cancer or receives a diagnosis of cancer, our veterinary oncology team is here to stage the cancer and treat the disease. VRC Oncology provides comprehensive care, which requires the most accurate diagnostic imaging modalities in order to apply the most effective medical, radiation, and surgical techniques. We take a multidisciplinary approach to treating pet cancer from every possible angle and may recommend a combination of treatments. Our goal is to cure the disease or slow its progression to prolong survival while preserving your pet’s quality of life. The safety and well-being of each pet is always our top priority.

Medical Oncology

VRC features dedicated chemotherapy suites to ensure safe and controlled administration of chemotherapeutic agents. Chemotherapy may be indicated for treating your pet’s cancer—either alone or in combination with other modalities, such as surgery or radiation therapy. While animals can experience side effects from chemotherapy, they are typically less severe than those experienced by humans. As with any procedure, our doctors review the risks and benefits of chemotherapy with pet owners and work closely with referring veterinarians to monitor and manage any side effects.

Radiation Oncology

VRC is one of a few veterinary hospitals in the country to offer the state of the art Varian Halcyon linear accelerator and Eclipse treatment planning system. The Halcyon’s capabilities include Intensity modulated radiation therapy (IMRT), Volumetric arc therapy (VMAT), Stereotactic radiation therapy (SRT), and Stereotactic radiosurgery (SRS).

The Halcyon’s Capabilities

Intensity Modulated Radiation Therapy (IMRT)

Modulates the radiation beam to deposit increased dose to the tumor while decreasing the dose to the normal tissues
Allows the treatment of multiple sites during the same treatment
Provides pain relief
Minimizes side effects
Offers improved quality of life
Consists of 5-20 treatments

Volumetric Arc Therapy (VMAT)

Advanced type of intensity modulated radiation therapy (IMRT)
Radiation is delivered continuously in an arc
Treatment times are much faster than conventional radiation therapy
More conformed dose distribution

Stereotactic Radiation Therapy (SRT) and Stereotactic Radiosurgery (SRS)

Higher does of radiation are given then traditional radiation treatments
Fewer side effects versus conventional radiation therapy
Fewer number of anesthetic events required for treatment
Curative intent radiation doses given within 1 week
Consists of 1-5 treatments

This advanced equipment enables us to address cancers previously thought to be untreatable by delivering high radiation doses directly to the cancer cells, thus sparing normal surrounding tissues. For some localized tumors, it offers a potential cure. In cases where pets have other life-limiting diseases or a cure is not possible, a lower overall dose of radiation therapy can be given to reduce pain, shrink the tumor, or slow its growth. This is called palliative radiation therapy.

Radiation Oncology FAQs

Will the radiation treatments burn my pet’s skin?

Radiation does not cause thermal injury to the skin. What we may see with radiation patients that have a tumor near the skin’s surface is called “moist desquamation.” Think back to a time that you skinned your knee on the sidewalk when you were playing as a child. The healthy, pink tissue that was exposed gave off a fluid (plasma) that hardened into a crust (scab). With radiation therapy, there is a mild amount of inflammation associated with this same change in the skin surface. Patients benefit from an oral anti-inflammatory medication, which we start at the beginning of treatment.

Moist desquamation is usually observed near the end of radiation therapy, and is generally healed within 2-3 weeks after treatments have completed. It is important to note that this skin effect only happens when surface tissues are targeted for radiation therapy – the same is not true for skin over tumors located deeper in the body.

Is radiation therapy painful?

Radiation therapy is not painful. The overall radiation dose prescribed is divided into small, daily or weekly treatments. Because there is no pain associated with the treatments, we use sedation or light anesthesia only to ensure that there is limited movement during treatment.

Will radiation treatment of my pet have effects on me/my children?

Unlike radiation treatments for a small subset of human and animal cancers, where radiopharmaceuticals (radioactive molecules in liquid form given by injection) are used for treatment, the radiation treatments at VRC are given using “external beam radiation.” These treatments are provided by a machine called a linear accelerator, which is a high-power x-ray tube. Similar to creating x-ray pictures, radiation is only given to the patient when the machine is on. When this machine is off, there is no radiation emitted, and no radioactivity is found at the treatment site on the patient. Feel free to cuddle and play with your pet just as you did before (s)he started radiation treatment.

Can my older pet tolerate multiple days of sedation/anesthesia?

A common phrase in veterinary medicine is “age is not a disease.” As we are more likely to diagnose cancer in older patients, the majority of patients undergoing radiation treatments are advanced in age. Checking baseline blood work is one measure we take to assess individual blood cell lines and organ health, ensuring our patients stay safe during procedures. More than likely, if the results are within normal ranges, your pet will be able to handle the medications we prescribe.

To further ensure safety under sedation or anesthesia, it may be recommended that your pet have chest x-rays or a heart ultrasound. Between the blood work and imaging studies, even mild changes that may be detected in the organs do not prevent treatment, as using sedation or anesthetic medications that are friendly to specific organs is easily accomplished.

Will my pet become sick from radiation therapy?

Radiation therapy is a localized treatment, so your pet should not experience vomiting, diarrhea, lethargy, or other signs of general illness as a direct result of the radiation treatments. Because of daily sedation or anesthesia, your pet may become tired near the end of each week during treatment. Some patients may seem a little tired and play less for 2-3 weeks after radiation therapy; however, most clients tell us that their pets act like a puppy or kitten again, even during treatment.

How long do radiation treatments take?

Overall treatment time is only 10-15 minutes. However, patients typically spend 1.5 to 2 hours with us each day of treatment. During this time, your pet received a daily physical exam, including an updated body weight assessment, a radiation treatment, and supervised recovery from sedation of anesthesia. If the location of your home does not allow for daily travel to our hospital, we offer boarding options for your pet.

What is the difference between definitive and palliative radiation therapy?

Definitive radiation therapy is given as daily treatments over 16-20 days, Monday through Friday. This protocol includes a higher overall dose of radiation for better tumor control, and for certain cancers, a cure.

Palliative therapy is reserved for patients who have a cancer that cannot be completely cured due to a variety of reasons. The goals of palliative radiation therapy are to reduce pain, decrease tumor size, and improve the quality of life for the time an animal has left. Palliative radiation therapy is given as once weekly treatments over four weeks, or daily treatments during one week. The overall prescribed radiation dose is lower as compared to definitive radiation, and palliative radiation offers a chance to treat with positive benefit when a complete cure is not possible.