Radiation Therapy, Combination Chemotherapy, and Amifostine in Treating Patients With Head and Neck Cancer

RATIONALE: Radiation therapy uses high-energy x-rays to damage tumor cells. Drugs used in chemotherapy use different ways to stop tumor cells from dividing so they stop growing or die. Chemoprotective drugs, such as amifostine, may protect normal cells from the side effects of radiation therapy and chemotherapy. PURPOSE: Phase I/II trial to study the effectiveness of radiation therapy plus combination chemotherapy and amifostine in treating patients who have stage II, stage III, or stage IV head and neck cancer that cannot be surgically removed.