I would question a precautionary post RT ND because ND's are generally not without complications and side effects.

I had a selective ND, on the right side and there are noticeable differences between that side and my left side. Nothing really bad; mainly a general tightness. Both sides got zapped.

But, recently I have noticed a mild on-and-off ache around my right ear. So far nasal scopes, etc haven't found anything, and it is probably nothing - perhaps RT fibrosis or late-effect ND nerve or muscle damage, but it means I am being scheduled for a follow-up PET/CT again this year.

Where I was treated ND's are generally avoided before RT, except to remove very large (potentially hypoxic) nodes or in cases where chemo is not advisable. Post RT they use a PET/CT to check the nodes.