What does SNT mean in medical?

Excuse me, but could you clarify something for me? I've come across the term "SNT" in a medical context, and I'm wondering what it stands for. Is it a specific medical condition, a treatment, or perhaps a type of medication? I'm hoping you might be able to shed some light on this for me, as I'm finding it difficult to locate a clear explanation through my own research. Any information you could provide would be greatly appreciated.