Discussion

Rowley K J, Morgan R, Malalana F, Knottenbelt D C
Aims: To determine the long-term outcome following treatment of periocular sarcoids with interstitial brachytherapy with Iridium-192. Methods: Twenty-five horses (n = 25) were included in the study. The owners were contacted and a telephone questionnaire filled out including signalment, time before treatment, response to treatment, complications, cosmetic results and owner satisfaction. Results: Mean age was 7 years. Of these cases 72% were geldings and 28% mares. Following treatment 40% of cases experienced complications which required veterinary attention. The majority of these were prolonged swelling and discharge; however, cases of cataract formation and loss of lid function were noted. Over half of the cases (52%) developed a scar, 60% had a hairless area, 68% had white hair growth, 4% developed a split lid and 4% lost the function of the lid. Maximal regression had occurred at 12 months in 82% of the cases,
13.5% by 24 months and in 4.5% of cases it took longer than 24 months. In those cases that developed eyelid swelling 63% resolved in 0 - 6 months, 31% in 6 - 12 months and in 5% it took longer than 12 months. Tumour recurrence occurred in 2 of the cases. Overall 84% of the owners were happy with the treatment. Conclusion: Interstitial brachytherapy with Iridium-
192 for periocular sarcoids appears to be an efficacious treatment with a success rate of over 90%, with 82% of cases reaching maximal regression by 12 months. Although complications following treatment are common most of these are relatively mild and well tolerated. Practical significance: Interstitial brachytherapy with Iridium-192 should be considered for the treatment of periocular sarcoids in horses.