PET Scans and CT Scans in Patients With Locally Advanced Head and Neck Cancer Undergoing Chemotherapy and Radiation Therapy

DISEASE CHARACTERISTICS: * Histologically or cytologically confirmed squamous cell carcinoma or lymphoepithelioma of the head and neck, including any of the following sites: * Oral cavity * Oropharynx * Hypopharynx * Larynx * Nasopharynx * Unknown primary of the head and neck region * Stage III or IV disease * Definitive chemoradiotherapy with curative intent must be planned PATIENT CHARACTERISTICS: * Able to tolerate positron emission tomography (PET) imaging * Not pregnant or nursing * Negative pregnancy test * Fertile patients must use effective contraception * No poorly controlled diabetes mellitus (e.g., fasting glucose \> 200 mg/dL) despite medication PRIOR CONCURRENT THERAPY: * See Disease Characteristics * No prior radiotherapy to head and neck