What PTV dose heterogeneity do you accept for head and neck radiation plans?

Around 10% but then I'll take the optic chasm to 70 Gy plus in order to adequately treat the tumor. I have a patient under treatment now in that situation. So I do what it takes. If it requires more heterogeneity, so be it.

For H&N mucosal tumors, I try to limit the heterogeneity to less than 105%. I don't have great data to support this, other than reviews of our institutional data with this approach. Very low comparative rates of reactive PEG insertion, low rates of hospitalization, and low rates of grade 3+ late tox...

Depending on the propinquity of the PTV to something you're aggressively trying to spare, always getting a max of 110% would seem to be a pretty aggressive constraint. Twenty percent or less of the PTV getting 110% or more would be more real-world achievable. The "problem" with PTVs is that they, by...