Radiotherapy in the treatment of sinonasal neoplasms in dogs

Abstract

Sinonasal neoplasms represent approximately 1% of all neoplasms and represent a major challenge for treatment. The treatment of nasal tumors must be local, and radiotherapy can be a good option in these cases. This study evaluated the therapeutic response of canine sinonasal neoplasms to megavoltage radiotherapy, and consequently, its influence on the survival and quality of life of these animals. We included 26 dogs with sinonasal neoplasms through histopathological and cytological examination. Dogs were treated with radiotherapy at total doses of 42-54 Gy (for carcinomas) and 45 Gy (for sarcomas) in 15-18 fractions of 2.8-3.0 Gy. Tumor staging was performed based on skull tomography. The most frequent clinical signs of sinonasal neoplasms were sneezing, nasal noise, and epistaxis. Acute side effects were mild and more frequent. Survival was evaluated based on tumor stage, obtaining a mean overall survival of 329 days (95% confidence interval, 229-428) and a median of 252.5 days. The survival time in animals in stage T3/T4 was significantly shorter than that in those in stage T1/T2 (P < 0.05). Moreover, 86.4% of the treated animals showed clinical improvement. Radiotherapy was well tolerated by dogs and effective in controlling sinonasal neoplasms.