Response of feline oral squamous cell carcinoma to palliative radiation therapy

Seven cats with advanced oral squamous cell carcinoma were treated with pal liative radiotherapy, Megavoltage radiation in 8 Gray (Gy) fractions was de livered on days 0, 7, and 21 for a total dose of 24 Gy, Treatment field inc luded the mandible, oropharynx, retropharyngeal lymph nodes, and tonsils. A djuvant treatment with chemotherapy was variable. Age ranged from 13 to 18 years old with a median age of 15 years. Three of the seven cats (43%) did not complete treatment. Six cats were euthanized due to tumor growth and/or radiation side effects with a median survival time of 60 days (range = 42 to 97 days, mean = 63 +/- 8.4 days). Radiotherapy complications or progress ion of disease occurred in 6 of 7 (85.7%) cats and included adverse clinica l signs, such as mucositis, serosanguinous oral discharge, pain, and dyspha gia, These data suggest that coarse fractionation radiotherapy did not resu lt in palliation in cats with inoperable oral squamous cell carcinoma.