Radiation Oncology FAQs

How does radiation therapy work?

Radiation therapy uses carefully planned, high-energy beams to damage cancer cells so they can no longer continue growing normally. Because normal cells can also be affected, we usually divide the total dose into a series of smaller treatments, called fractions. This approach helps focus treatment on the tumor while protecting healthy tissue.

What are the goals or benefits of radiation therapy?

Radiation therapy can be used with different goals depending on the diagnosis and overall treatment plan.

• Definitive radiation therapy is used when the goal is long-term local tumor control, including for some tumors that can’t be safely removed with surgery.
• Adjuvant radiation therapy is used to target cancer cells that may remain after surgery. The goal promotes long-term tumor control.
• Palliative intent radiation therapy is used when long‑term control is not possible or not the primary goal, but symptom relief and improved comfort are important. Palliative intent radiation therapy can slow tumor growth and relieve symptoms. Many pets feel better and have an improved quality of life when radiation reduces tumor-related pressure, pain, or bleeding.

Are there risks involved?

Yes. As with any cancer treatment, radiation therapy has potential risks and side effects. Because radiation affects tissues in the treatment area, some normal tissue near the tumor may be impacted. We design each treatment plan to reduce risk as much as possible and will review the most likely side effects based on your pet’s specific tumor location, treatment plan, and goals of care.

Does my pet need anesthesia?

Yes. Pets must remain completely still for treatment to be delivered accurately and safely, so general anesthesia is needed for each session. Although anesthesia always carries some risk, most pets tolerate it very well. We use pre‑anesthesia testing and tailor the anesthetic plan to your pet’s individual needs.

How is radiation therapy delivered?

Radiation therapy is usually delivered with a radiation machine, or linear accelerator, which directs radiation to the tumor and a small margin of surrounding tissue. A typical visit usually includes check‑in, a brief health assessment, IV catheter placement, anesthesia, treatment, and recovery. While the actual radiation treatment itself is usually brief, the full visit may take 2 to 3 hours.

How many treatments will my pet need?

Radiation is given in a series of treatments, or fractions. The total number of visits depends on several factors, including:

• Tumor type
• Tumor location
• Your pet’s overall health
• Whether the goal is long-term control (definitive) or comfort (palliative)

We’ll recommend a treatment plan after reviewing your pet’s records and any imaging/biopsy results.

What side effects should I expect?

Side effects depend on the area being treated and the type of radiation protocol used. Most side effects, while frustrating, are localized to the treatment area and are temporary and manageable.

Common early, or acute, side effects often begin 2 to 3 weeks after treatment starts. In some cases, acute side effects may continue to worsen for 1 to 2 weeks after completing treatment before they begin to heal. These acute side effects usually heal within a few weeks of completing treatment.

• Skin redness or irritation in the treated area
• Hair loss in the treated area
• Local tissue irritation, such as mouth or nasal irritation, when those areas are treated

Late side effects are less common but can develop months to years after treatment and may be permanent.  If you notice a new problem in the treated area later on, please contact us for guidance.

What should I do if my pet’s skin becomes irritated?

Skin irritation in the treatment area can progress to moistness or crusting, similar to a severe sunburn. It’s important to prevent licking, scratching, or rubbing since this can worsen discomfort and delay healing. We may prescribe medication and/or recommend an e‑collar to help protect the area. Please don’t use over‑the‑counter creams or medications unless our team has specifically recommended them.

Will my pet be sick to their stomach from radiation?

Most pets do not develop vomiting or diarrhea from radiation therapy unless part of the abdomen is in the treatment area. We will explain what to watch for based on your pet’s specific treatment site.

What should I expect at the first treatment appointment?

At the first treatment visit, you will check in at your scheduled time, and our team will admit your pet and review how things have been going since the previous visit. A clinician may not always be available right at check-in, but our technicians can answer many routine questions. If you have more detailed concerns, you are always welcome to call ahead or discuss them with the team at discharge.

If my pet is coming daily, can I have set drop-off and pick‑up times?

We try to keep our appointment timing consistent, though schedules may vary based on hospital needs and patient care priorities. Most treatment visits take about 2 to 3 hours from the scheduled appointment time to discharge.

Can my pet eat the morning of treatment?

Because anesthesia is required, it is important to follow fasting instructions carefully.

• Please DO NOT feed your pet after midnight the night before treatment (including treats).
• Water is okay up to the time of the appointment.
• Morning medications should be given as usual unless you were told otherwise. If needed, medications may be given in a SMALL treat.
• If your pet is diabetic, follow the specific instructions provided by the internal medicine or radiation oncology team.

Why is my pet shaved or marked?

We may clip hair and place small ink marks on the skin to help ensure  consistent positioning throughout the treatment course. If markings are placed, we will let you know whether bathing or swimming should be limited to help preserve them.

Should I bring my pet’s bed, toys, or food?

Usually, no. Because treatment visits are relatively short and many patients share treatment and recovery areas, personal items can be difficult to store and may be misplaced. If your pet needs a special diet or medication, please bring those as instructed.

Is radiation therapy expensive?

Radiation therapy can be costly because it involves  advanced equipment, specialized planning, anesthesia and a specialized clinical team. Costs vary by tumor type and number of treatments. We will provide an estimate and discuss payment timing/options.

What happens after treatment is finished?

After radiation treatment is completed, we will schedule recheck visits to monitor healing, side effects, and tumor response. The first recheck is often about 2 weeks after completion, followed by additional visits every few months, depending on your pet’s diagnosis and treatment goals. In some cases, repeat imaging, such as CT, may be recommended several months after treatment to assess response.

What results should I expect?

Some tumors shrink significantly and may go into remission; others may not fully disappear but can stop growing or grow more slowly for a period of time. Expected outcome depends on tumor type, location, stage of disease, and treatment intent. We will discuss the expected outcome for your pet’s specific case so you have a realistic understanding of your pet.

What if my pet has an emergency?

• During business hours: call us at 865‑974‑8387.
• After-hours emergency (8:00 a.m.–12:00 a.m.): call 865‑974‑8387.

If your pet needs immediate care and you are closer to another emergency clinic, go there and let them know your pet is receiving radiation therapy.

Contact & Location (UTCVM)

Phone: 865‑974‑8387