Do you use any thyroid dose constraints for head neck radiation planning?
I do not constrain the thyroid. Careful monitoring post-operatively for hypothyroidism and appropriate thyroid replacement is reasonable. There is another, more theoretical concern that I have in that based on a Childhood Cancer Survivor Study Analysis, intermediate RT doses to the thyroid (10 - 30 ...
I agree with Dr. @Dr. First Last, although this is an area in which I would be interested in other comments. I suspect that larynx dose constraints protect the thyroid to some degree in cases where the larynx is not a target. Constrictor muscle dose constraints may play a role, too.
All that said, ...
Yes, in select cases where I am only covering electively in the area:
V30 < 60%
Mean < 4500 cGy
I would not undercover gross disease to meet these constraints nor crop the elective PTV extending into the thyroid.