Delia,
My husband had his chemo (2 treatments) prior to radiation, none during. There is no sign of cancer in his larynx and he regained the use of his left vocal cord, which was frozen by the cancer prior to treatment. He still had a positive lymph node after treatment that was removed during his modified neck disection. Hope this helps ease your worries. He is 9 months from the end of radiation. You are in my prayers for a positive outcome.
Linda