In what situations would you consider treating metastases to the spine with proton SBRT?

For any question I must rely on evidence to answer it.

So the first thing is- what is the published data on the use of proton SBRT for spine metastasis (not primary spinal cord tumors)?

I am unaware of any outcomes data, and after a quick pubmed search I found zero papers (not even retrospective out...

I must agree with Dr Spratt's answer above. I'm not aware of any proton SRS/SBRT series or even case reports for metastases. It's not unreasonable to attempt this on a prospective IRB approved registry protocol, but photon SRS/SBRT to spine metastasis is so well tolerated there doesn't seem to be mu...