What tissue tolerance constraints do you use for the esophagus, spinal cord, and heart for reirradiation of a NSCLC mediastinal lymph node failure?

I opted to write a response to this question, but honestly the answer is elusive to me.

With respect to SBRT: for spinal cord, I rely on Dr. Sahgal’s work (he has several papers on this topic); for other organs, there are less data.

For conventionally fractionated radiation, most are familiar with th...