How do you evaluate and constrain the cumulative lung DVH for inoperable patients who have received multiple courses of lung SBRT and now require fractionated mediastinal RT?

This is an increasingly common problem and there are few data to guide decision making.

However, some have looked at dosimetric-toxicity relationships in the reirradiation setting (either re-SABR or conventional radiation after SABR).

It's suggested that composite high dose to a previously irradiated ...