Veterinarians at the University of Florida have begun using some of the worlds most advanced radiation planning and treatments on small animals with brain tumors and other tumors in the head region. Known as stereotactic radiosurgery, the original method has evolved as the treatment of choice for humans with certain types of intracranial tumors since its inception more than a decade ago.
Still in the early stages of evaluation, the new technique allows pets to be treated in one session of high-dose, precisely targeted X-ray treatment rather than through repeated sessions over a period of weeks. We have been able to transfer this technology to animals and are using it to benefit our cancer patients, says Nola Lester, BVMS, a radiologist at the University of Florida College of Veterinary Medicine.
Most patients have had brain tumors and other tumors in the head region, although the procedure is also being used to treat vaccine-associated sarcomas in cats.
Animals also receive a single dose of anesthesia rather than the several that would be administered over a period of time during traditional fractionated therapy, in which a lower dose of radiation is given in a more general region of the area surrounding the tumor than the single dose delivered with radiosurgery. In a fractionated course of treatment, 16 to 19 treatments, or fractions, are usually delivered on a daily basis, Monday-Friday, over a period of three or more weeks; the total dose of radiation is typically higher with a fractionated course of treatment.
Lester cautions that the procedure is sometimes more effective that at other times. In some cases, we have seen fantastic results and the tumor completely disappears, she says. In others, this is not the case. So we are still in the early stages of figuring out what responds well and what doesnt.