Dad is 11 weeks recovering neck discection and 6 weeks of radiation. Does anyone or has anyone heard of experiencing terrible swelling at this stage after radiation?

yeah of course, it's very common. it can last months and months. i had radiation in august, and the inside of my throat still has swelling as well as some lost sensation. And i had a neck dissection about 5 weeks ago and my neck is still quite swollen. it's not uncommon at all.

Common - normal.
I still have swelling and tenderness internally.
Darrell