I was told the ND protocol is determined by the tumor board after considering staging, guidelines, and extenuating circumstances.

In my situation the chemo was replaced with SND surgery "first" because I have impaired kidney function. Also standard IMRT was replaced with TomoTherapy.

My ENT has mentioned complications that can arise from ND surgery when the nodes are near or attached to critical nerves, arteries, etc.. and that using chemo "first" (or concurrently) can often mitigate having to deal with these issues.

I also remember reading an article that mention the possibility of accidentally spreading microscopic cancer during ND surgery.

I would think if a ND was still necessary post RT that the nodes would be must smaller and less invasive so that it should be easier to get good clear margins.