Radiation Therapy offers another option for pets with certain types of cancer. There are a number of different types of radiation therapy used to treat cancers.
Tumors are irradiated with beams of photons, electrons or gamma rays.
The ray is concentrated on the nucleus of a cell changing it so that the cell’s ability to divide and grow is destroyed.
Radiation can affect normal cells as well, but steps are taken to minimize the effect.
Thyroid disease and hypothyroidism in cats can be treated with injections of radioactive iodine.
Radioactive implants have been used to treat nasal tumors in dogs and fibrosarcomas in cats.
Human patients receiving radioactive thyroid treatments usually go home immediately after treatment. However cats and dogs are quarantined from 2-5 days under government rules, even though they receive lower doses. There is an ongoing controversy that human standards should be at least as protective as those for animals. At home, precautions must be taken handling radiation treated pets’ urine and feces.
Animals are examined before treatment and x-rays, MRIs and/or CAT scans are used to find the exact location of the tumor. With beam radiation, the machine is then programmed to send the beam to these locations. Actual treatment time is short, but your pet needs to be anesthetized so as not to move.
Radiation therapy can take from 2-5 weeks depending on the animal’s health and tolerance and location of the tumor. Palliative treatments are usually once a week for 3 weeks.
Side effects can be skin problems, similar to sunburn, itchiness which can be reduced with medications and hair loss. Cells that reproduce slowly can cause chronic side effects. In that case the dose may be decreased or radiation discontinued.
Radiation therapy usually does not cause the side effect of chemotherapy such as nausea, tiredness or inappetance.
The cost of radiation therapy can be high. Consult with your vet/oncologist beforehand to be sure your pet is a candidate for radiation therapy..