Radiation Therapy With or Without Cetuximab in Treating Patients With Stage III or Stage IV Cancer of the Oropharynx, Hypopharynx, or Larynx

RATIONALE: Radiation therapy uses high-energy x-rays to damage tumor cells. Monoclonal antibodies such as cetuximab can locate tumor cells and either kill them or deliver tumor-killing substances to them without harming normal cells. It is not yet known if radiation therapy is more effective with or without cetuximab for cancer of the oropharynx, hypopharynx, or larynx. PURPOSE: Randomized phase III trial to compare the effectiveness of radiation therapy with or without cetuximab in treating patients who have stage III or stage IV cancer of the oropharynx, hypopharynx, or larynx.