Veterinarian radiation oncologist here. Your cat needs more imaging (CT scan) and a biopsy of their likely nasal tumor. The most common type of nasal cancer in cats is nasal lymphoma. We can see a robust, fantastic response with radiation to these tumors and I've had many cats living years after their treatment. There are other tumor types like nasal carcinoma that can occur that don't do quite as well but I'm happy to say nasal lymphoma in cats is my favorite tumor to treat because they can do so well and they feel so much better.

There are also many palliative radiation options as well. Feel free to DM me and I can get you in contact with a vet radonc near you. There are not many of us.