Diagnosis of an intraluminal aortic chondrosarcoma via transarterial biopsy and treatment with stereotactic body radiation therapy in a dog.

An intraluminal aortic mass was incidentally found on CT scan in a 2-year-old Flat coated retriever. The mass was larger on repeat CT and was biopsied via right femoral artery catheterisation using endoscopic biopsy forceps. Histopathological examination confirmed an aortic chondrosarcoma. The aortic chondrosarcoma was treated with stereotactic body radiation therapy with 8 Gy delivered in three fractions every other day to a 24 Gy total dose. Follow-up CT 5 months post stereotactic body radiation therapy showed stable disease. No adverse effects secondary to the biopsy procedure or stereotactic body radiation therapy were observed; however, progressive disease was noted 8 months post stereotactic body radiation therapy. The same SBRT protocol was repeated. The dog remained clinically well until presentation 84 days later with signs of multiple organ dysfunction syndrome and was subsequently euthanised.