What constraints do you use for the gallbladder when giving liver SBRT to lesions close to the gallbladder?

I am not aware of any published data of toxicity to the gallbladder organ proper, and when we do liver SBRT we do not contour the gallbladder. I'd be interested if others have noted what could be called radiation induced gallbladder toxicity.

The bile duct is a much more significant OAR given risk of stenosis and cholangitis, which we do contour (especially if in close proximity) and limit dose as per published guidelines.

If it is close to the bile duct (we usually look at the common bile duct and it's bifurcation into the cystic and hepatic ducts as one structure) we generally do a 5 fraction regimen and avoid point doses of 41Gy per Timmerman tables. Most liver SBRTs at our institution are not in close proximity to the bile duct, however...