Your veterinarian has diagnosed your feline companion as having hyperthyroidism due to a small tumor in the thyroid gland. While slow growing, these tumors cause a change in your cat's metabolism that can make them uncomfortable and shorten their lives. The vet has recommended radiation treatment, which will get rid of the tumor, and your cat's symptoms. Here is how this treatment works and what to expect during and after your cat's treatment.
Radiation and Cancer Cells
The treatment is done in a special facility with staff trained in the handling of radioactive material. Radioactive iodine is injected into your cat's bloodstream. This circulates throughout your cat's body until it is absorbed by the thyroid, which naturally interacts with iodine. The radiative material is drawn to the rapidly reproducing cells in the thyroid tumor. The less active healthy cells absorb little of the radioactive iodine.
The radioactivity disrupts the reproductive process of the tumor cells and kills them. As these cells die off, the normal healthy cells take over the production of thyroid hormone. As more of the healthy cells regain control of the hormone production, you cat's metabolism slowly returns to normal. Any remaining iodine that was not absorbed by tumor cells is released from the body in the cat's urine.
The Treatment Timeline
The radioactive iodine takes only a few minutes to begin reacting with the tumor. In few hours, healthy cells begin to take back their role in the thyroid gland and the excess radioactive material begins to show up in the urine. The clinic will monitor your cat's urine for this material and they will be required to stay at the cat hospital until the radiation level in the urine is safe for the cat to go home.
The goal of the treatment is to give your cat the least amount of radiation necessary to destroy the cancer cells and produce a minimum amount of radioactive waste. The amount of radioactive iodine given to your cat depends on the cat's weight and the size of the tumor. Your cat may need to stay overnight and part of the next day until the radiation level in the urine is safe for them to leave.
What to Expect When You Get Your Feline Friend Home
Your cat will continue to release small traces of radioactivity in their urine for a few weeks. While the amount is small, your veterinarian is concerned with your accumulated exposure to the radiation. You'll be given a set of instructions as to how to handle your cat for the next few weeks, such as:
- limiting your contact with your cat to a few minutes each day
- restricting access to your cat by other family pets
- washing your hands after contacting your cat, its food and water dishes, and the litter box
Most of the radioactive material ends up in the litter box, so you'll have special instructions as to handle that:
- scoop the litter into a pail lined with a heavy plastic bag
- when the pail is full, seal it tightly with a lid
- place the pail in a location where it won't be disturbed for several weeks
- after that period, place the sealed pail out with the trash
Your cat will have a follow-up appointment with the vet (such as one from Abri Animal Hospital) after a few weeks to check the radiation levels in the urine. If the levels have reached normal, you can resume contact with your cat without the additional precautions.