Radiation Therapy With or Without Chemotherapy in Reducing Mouth Dryness in Patients With Nasopharyngeal Cancer

DISEASE CHARACTERISTICS: Histologically confirmed stage I-IVB squamous cell carcinoma of the nasopharynx WHO I-III No stage IVC disease No evidence of distant metastasis Measurable or evaluable disease Must have been treated with primary radiotherapy PATIENT CHARACTERISTICS: Age 18 and over Performance status Zubrod 0-1 Life expectancy Not specified Hematopoietic White blood cell count (WBC) at least 4,000/mm^3 Platelet count at least 100,000/mm^3 Hepatic Not specified Renal Creatinine no greater than 1.6 mg/dL Creatinine clearance at least 60 mL/min Other Not pregnant (If stage T2b or greater or node-positive disease) Negative pregnancy test (If stage T2b or greater or node-positive disease) No other prior head and neck cancer No other malignancy within the past 5 years except nonmelanoma skin cancer No active untreated infection No other major medical or psychiatric illness that would preclude study entry Nutritional and general physical condition compatible with radiotherapy NOTE: *If stage T2b or greater or node-positive disease PRIOR CONCURRENT THERAPY: Biologic therapy Not specified Chemotherapy More than 6 months since prior chemotherapy Endocrine therapy Not specified Radiotherapy See Disease Characteristics More than 6 months since prior radiotherapy for head and neck cancer Surgery No prior head and neck surgery to the primary tumor or lymph nodes except incisional or excisional biopsies Other No other concurrent experimental therapy for cancer No amifostine or pilocarpine during or for 3 months after radiotherapy