Iridium-192 Therapy (Brachytherapy)

Iridium-192 therapy is used to treat sarcoids and other skin tumours. It is especially useful for the treatment of tumours that are in difficult locations (such as around the eye or over joints), or that have recurred despite other treatments.

The treatment involves the insertion of small radioactive seeds directly into the tumour using sedation and local anaesthesia. The seeds are then left in place for a set period of time, usually 4-7 days, during which time they emit radiation directly into the area to kill the abnormal cells. At the end of the treatment, the seeds are removed and there is no residual radiation left in the horse.

Iridium treatment is usually highly successful and the success rate following treatment is usually 80-100%.

Before the horse is admitted, digital photos of the lesion are studied to allow the correct size and activity of iridium seeds to be ordered. The horse is then admitted the day before treatment and then stays for 5-7 days. During treatment, handling of the horse is kept to a minimum to reduce the levels of radiation exposure. Some swelling is common after treatment, but if treatment has been effective the tumour gradually shrinks over the next 2-4 months. Some horses develop some mild scarring or white hairs at the site of the tumour but the cosmetic result is usually very good.

If you have any specific questions or would like to refer a horse for treatment, please contact Emily Haggett at Rossdales Equine Hospital.