Abstract

Background:
Feline nasal epithelial tumors are locally invasive and radiosensitive, and radiotherapy is the standard treatment. However, recurrence is common, and the role of reirradiation in cats remains unclear.

Aim:
This retrospective study aimed to evaluate the efficacy and safety of hypofractionated reirradiation in cats with recurrent nasal epithelial tumors.

Methods:
The medical records of cats treated with hypofractionated radiotherapy for intranasal epithelial tumors at Azabu University Veterinary Teaching Hospital between 2014 and 2022 were reviewed. Follow-up continued until August 2023.

Results:
Twenty-six cats were treated, 11 of which underwent reirradiation after clinical progression. The median interval between treatments was 356 days. In the first course, responses included complete (n = 1), partial (n = 7), stable (n = 16), and progressive (n = 2) diseases. In the second course, all cats achieved stable disease. The median overall survival was significantly longer in the reirradiation group than in the nonreirradiation group (562 vs. 58 days, p

Key words: Adverse event; Feline; Nasal tumor; Recurrence; Reirradiation.