Would you offer lung SBRT for an individual with rheumatoid arthritis?

I wouldn't hesitate to use SBRT in this setting, all things being equal. The important caveats for "equal" are whether they have any component of interstitial lung disease. I'm very fortunate to have access to proton therapy, and about the only time I use it for SBRT lung is in patients with severe interstitial lung disease. In those patients the integral dose does seem much more important and it's worth going the extra mile (or km depending on your point of reference). For the generic, non ILD patients, it's all beam on and pass out the cure, in my opinion. I've treated patients with RA many times with no serious issues (in the absence of ILD). For non-proton plans I'd favor running the center up to 140% in order to get better dose fall of...