What ipsilateral lung constraints if any do you utilize for SBRT and or hypofractionated RT in the lungs?

Following up to this question, I wanted to see if there are any new thoughts on this. I think most rad oncs who I have asked, do not really utilize an ipsilateral lung constraint for SBRT or hypofractionated 60/15 style plans.

I was wondering if this might be related to old school rules of thumb, like not treating lesions much larger than 4-5 cm with SBRT, and as a result, that smaller size cutoff probably kept ipsilateral lung dose from ever being a major issue for most patients in the past.


As I'm finding myself treating larger tumors with hypofractionation for patients who can't get systemic therapy or very commonly treating multiple oligometastatic lesions in one lung, I'm often feeling a bit uneasy when looking at high ipsilateral lung...