(NU12) Low-dose Radiation Therapy: A Novel Treatment for Feline Idiopathic/interstitial Cystitis

Abstract: Background - Feline idiopathic cystitis (FIC) accounts for the majority of feline lower urinary tract (LUT) disease. Severe morbidity and frequency of urethral obstruction (UO) often results in euthanasia. Despite many studies, severely affected cats remain difficult to manage. Low doses of radiation therapy (RT), which effectively reduce pain and inflammation in other disorders, has not been studied.
Hypothesis/Objectives - The purpose of this study is to determine the feasibility of using a single fraction of low-dose RT to reduce rate of re-obstruction and recurrence of clinical signs in cats with FIC.
Animals – Five client-owned male cats with recent history of severe FIC and/or recurrent UO that had been managed with environmental modification and/or pharmacological management.
Method – Single-arm clinical trial to establish proof-of-concept for low-dose RT. All cats were anesthetized and received a total of 6 Gy in a single fraction to the urinary tract. A standardized questionnaire was administered to the owners at baseline and then every 30 days for up to one year.
Results – All cats tolerated RT with no adverse effects. Two cats completed one year of follow-up. To date, none of the cats have had recurrence of LUT signs or UO.
Conclusion and clinical importance – This pilot study concludes that a single low-dose fraction of RT to the urinary tract is a safe and viable treatment option for cats with FIC. In addition to environmental modification, low-dose RT may reduce the severity and frequency of clinical signs associated with FIC in cats.