Radiation Therapy and Cisplatin With or Without Cetuximab in Treating Patients With Stage III or Stage IV Head and Neck Cancer

RATIONALE: Radiation therapy uses high-energy x-rays to kill tumor cells. Drugs used in chemotherapy, such as cisplatin, work in different ways to stop the growth of tumor cells, either by killing the cells or by stopping them from dividing. Cisplatin may also make tumor cells more sensitive to radiation therapy. Monoclonal antibodies, such as cetuximab, can block tumor growth in different ways. Some block the ability of tumor cells to grow and spread. Others find tumor cells and help kill them or carry tumor-killing substances to them. Giving radiation therapy and cisplatin together with cetuximab may kill more tumor cells. It is not yet known whether radiation therapy and cisplatin are more effective with or without cetuximab in treating head and neck cancer. PURPOSE: This randomized phase III trial is studying radiation therapy, cisplatin, and cetuximab to see how well they work compared to radiation therapy and cisplatin in treating patients with stage III or stage IV head and neck cancer.