Piroxicam, Mitoxantrone, and Hypofractionated Radiation Therapy with Volumetric Modulated Arc Therapy for Treating Urinary Transitional Cell Carcinoma in a Dog: A Case Report

Abstract

A 12-year-old spayed female beagle dog was presented with pollaki uria and stranguria. Abdominal ultrasonography identified irregular a marginat ed, hyperechoic mass in the urethra and trigon area of the bladder. Computed tomography (CT) revealed a heterogeneous mass in the trigone area leading to a urethra. There was no evidence of regional or distant metastasis. Cytologic analysis suspected transitional cell carcinoma (TCC). The patient was treated with piroxicam, mitoxantrone, and once weekly fractionated radiation therapy (RT) with volumetric modulated arc therapy (VMAT). A follow-up CT scan at 6 months after RT revealed a reduction in tumor size. At 17 months after the start of RT, the patient became severely anorectic and lethargic. Ultrasound examina tion revealed a hyperechoic mass in the apex area of bladder while the trigone area of the bladder and urethra appeared normal. Multiple hypoechoic nodules of various sizes were found in the liver and spleen. The patient was humanely euthanized at the request of the owner. A combination of piroxicam, mitoxan trone, and hypofractionated RT with VMAT protocol was well tolerated. This case described tumor response and survival time of a canine TCC treated with piroxicam, mitoxantrone, and once weekly palliative RT using computer-assisted planning and VMAT.