If you are unable to meet V50% dose constraint for partial breast irradiation, do you revert to whole breast treatment?

I believe you are referencing the V50 constraint in 5 fraction PBI based on the uninvolved breast volume.

In cases where this is the situation, I first see how much I am exceeding the criteria by, if it's not a lot, I will consider proceeding with 30/5. If it's significantly exceeded, one option I co...

Our preference for this situation is FAST-Forward dose and fractionation (26 in 5 to whole breast).