Is there data to suggest that definitive chemoradiation to 70Gy vs. postoperative chemoradiation to 60 or 66Gy has any different clinically significant effects on long term swallowing function and other side effects of H&N cancer treatment?

Our ENT surgeons often tell patients with evidence of matted nodes on imaging that their swallowing function will be much worse after 70Gy as compared to 66 or 60 Gy. I feel that if there are level 2 nodes with extracapsular extension that require 66Gy postoperatively, it is difficult to spare the tonsil or BOT from getting much less than 63-66Gy as the isodose lines tend to bleed into the tonsil or BOT.