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 excision…