33rd Annual Scientific Meeting proceedings

Introduction
Urothelial carcinoma (UC) is the most common canine urinary bladder cancer. Surgery and chemotherapy are currently considered the most effective at improving survival, but the prognosis remains poor. Intraoperative radiotherapy is an appealing approach to provide local tumour control, however only two studies have been published on radiotherapy for canine UC, making additional and recent data invaluable.

Materials and Methods
Medical records of dogs with histologically confirmed bladder UC treated with one-dose of intraoperative radiotherapy (8 Gy delivered dose, 6 meV electrons from a linear accelerator) and COX-2 selective NSAID were retrospectively reviewed. Reported data included complete blood count, serum biochemical analyses, urinalysis, thoracic and abdominal imaging (including CT scan for measurement of UC), and complications.

Results
Twenty-three dogs were included in the study. The median survival time and median disease-free interval were 432 and 245 days respectively. The 1-, 2- and 3-year survival rates were 56%, 27%, 12%, respectively. Histological differentiation and vascular invasion was significantly and negatively correlated with patient survival. Complications associated with treatment occurred in 52% of dogs and were considered as mild and self-limiting in 67% of these cases; long-term urinary incontinence occurred in 22% of the cases.

Conclusion
The results of this retrospective cohort study suggest that one-dose intraoperative radiotherapy and COX-2 selective NSAID are relatively well tolerated and may be a treatment option for canine UC.