Colorado Animal Specialty & Emergency (CASE)
CASE offers cutting-edge technology as one of the few veterinary hospitals utilizing a Varian Halcyon linear accelerator. This allows for delivery of advanced radiation with extreme precision, resulting in decreased radiation to the adjacent normal tissues and less side effects while still delivering accurate doses of radiation to the tumor.
We offer Intensity modulated radiation therapy (IMRT), Volumetric arc therapy (VMAT), Stereotactic radiation therapy (SRT), and Stereotactic radiosurgery (SRS).
Types of Radiation Therapy
There are 2 main intents of radiation therapy: palliative and definitive.
Definitive intent radiation is utilized when there is a potential for long-term control of a tumor.
Finely fractionated radiation consists of delivery of small daily doses given Monday through Friday over 3-4 weeks.
Stereotactic radiation is another definitive methodology that is highly specialized and typically delivered over 1-5 closely scheduled treatments.
Palliative radiation therapy consists of fewer larger doses (fractions) of radiation with the intent to alleviate pain and clinical signs associated with the tumor. Palliative radiation therapy is used to improve the patient’s quality of life and typically does not have long term control.
The exception is Coarse Fractionated radiation therapy. This therapy uses larger doses per fraction, as in palliative therapy, however the goal is definitive/long term control. There are certain tumors that respond better to this type of protocol such as melanoma.
Advanced Treatment Modalities
IMRT
Intensity-Modulated Radiation Therapy is a sophisticated form radiation planning. IMRT can be used when delivering definitive (finely fractionated or stereotactic radiation therapy) or palliative intent radiation therapy. CASE is currently one of only two veterinary hospitals in Colorado to offer the treatment. IMRT allows for the radiation dose to conform to the shape of the tumor by modulating (adjusting) the intensity of the radiation beams. The individualized radiation plan utilizing IMRT is intended to maximize the dose delivered to the tumor while simultaneously protecting the surrounding normal tissue.
IMRT also improves the ability to conform the treatment to tumor shapes, for example when a tumor is wrapped around a vulnerable structure such as the spinal cord, a major organ, or blood vessel. The net effect is that radiation doses can be “wrapped” around tumors, or “painted” within tumors, far more precisely than was previously possible. Radiation therapy, including IMRT, stops cancer cells from dividing and growing, thus slowing or stopping tumor growth. Radiation therapy in general is often used in conjunction with surgery and/or chemotherapy.
Stereotactic Radiation Therapy
Stereotactic radiation therapy (SRT) is a highly specialized form of radiation delivery that delivers 1-5 highly conformal doses of radiation to a tumor with submillimeter accuracy.
Multiple terms have been used for stereotactic-based radiation that includes stereotactic radiosurgery (SRS), stereotactic ablative radiation therapy (SABR), and stereotactic body radiation therapy (SBRT). In a purest sense, SRS is used when describing a single high dose of radiation delivered to a lesion in the brain. Stereotactic body radiation is used to describe when delivering high dose radiation over 1-5 treatments outside the brain.
Image-Guided Radiation Therapy
Image guided radiation therapy (IGRT) uses images of the patient at the time of treatment to determine the accuracy of setup so that corrections can be made in real time before the treatment is delivered. Our system uses cone beam-CT scans (CBCT) to confirm patient positioning to within millimeters of error.
Volumentric Arc Therapy (VMAT)
Volumetric modulated Arc Therapy is an innovative form of intensity modulated radiation therapy (IMRT) that delivers precise continuous radiation in a single or multi-arc treatment to patient. With conventional IMRT techniques like step-and-shoot, the machine must make repeated stops and starts to treat the tumor from a number of different angles generally over 5-10 minutes. In comparison, VMAT can deliver the dose to the entire tumor in a 360-degree rotation, typically under two minutes.
