Nelie is correct -- regardless of the "T Stage" (Relative size of the primary), metastasis to multiple nodes makes this Stage IV disease. I had a primary on my tongue that was at the lower limit of the T2 range for size, but was stage IV because of metastasis to lymph nodes. I had bilateral neck dissection, but they did not operate on the tumor itself -- used radiation both to kill the primary and kill any spread in the neck and elsewhere.
I would certainly not take a chance with disease that had gone to multiple lymph nodes, but again that is a personal decision, so long as he fully understands the implications and risks of not having the radiation.