Gwen
Welcome to the forum. I'm sorry to hear about your brothers condition. Can you give any more detail on what treatment he's undergone? Stage IV doesn't mean terminal; I had a stage IV cancer in my jaw, and I'm doing real well, all things considered.

I can't tell you whether Cesium Chloride is the right choice to make; I can tell you an unproven and unendorsed treatment like that would not have been a choice I would have made, but that's me. Quackwatch considers it to be a highly questionable and unsubstantiated.

Proven treatments are just that; proven. There aren't many success stories with alternative treatments that can be verified, for pretty good reason. Best of luck with your decisions
Wayne