Efficacy of hypofractionated radiotherapy for nasal tumours in 38 dogs (2005–2008)

Abstract

To evaluate the efficacy of hypofractionated radiotherapy for canine nasal tumours, including the improvement in clinical signs, rate of complications and assessment of prognostic factors. Medical records of 38 dogs with malignant nasal tumours were reviewed, and those treated with a weekly schedule of hypofractionated radiotherapy were included in the study. Acute and late side effects were defined as complications noted either within 1 month or after 6 months of irradiation, respectively. Progression-free interval and overall survival were calculated using the Kaplan-Meier method. Log-rank test and Cox proportional hazard model were also performed. Clinical signs improved in 30 of 36 dogs. Acute complications were seen in 28 of 36 dogs and were considered manageable. Late complications were observed in 17 of 30 dogs that survived 6 months or longer, but severe side effects were not observed. The median progression-free interval and overall survival was 245 days (95% CI: 127-512 days) and 512 days (95% CI: 203-820 days), respectively. Age, breed and presence of dyspnoea were negatively correlated with overall survival. These results suggest that hypofractionated radiotherapy could be a viable option for the treatment of nasal tumours in dogs that are not candidates for conventional multi-fractionated radiotherapy.