Acvtually, a number of the top CCCs are no longer routinely doing neck dissections because some recent studies have found a modest improvement (wih ND) in local control -- about 5-10% -- but no long-term survival advantage. And a significant increase in morbidity (bad side effects). Many doctors do not like the idea of long, unnecessary surgeries and the newer treatments are so effective that our ENT said most of the NDs he does show no cancer. For this reason at Hopkins it is not promoted by the MOs and ROs, and even the surgeons are cautious -- they do a lot of testing. Even if there are suspicious areas (with a fused PET/CT) they will order an MRI and maybe some other things before doing any surgery.
At Sloan-Kettering , where we went for a second opinion, we were quite bluntly told "we don't do them"

You may wish to google for some of the recent studies on effectiveness or need for post-treatment neck dissection. The current thinking seems to be moving towards doing it only in selected cases.

Gail