This study will involve an examination of the patient to evaluate mucositis, collection blood samples for analysis of specific indicators of nutritional status and completion of questionnaire regarding food intake and functional status. Blood samples will be collected and brief questionnaires about diet and weight status will be completed at each of the three visits. Visits will occur before treatment begins, at the end of XRT treatment and 4-6 weeks after completion of XRT. Assessments for the presence and severity of mucositis and functional status (Karnofsky) will be done at each visit. All of the samples and data collection will be done at visits to clinic required for the patients' treatment. If it is necessary to obtain blood samples from the central venous catheter, this will be done using aseptic technique and will be performed by a nurse. In some instances, the information obtained as part of this project may be used to reduce side effects of therapy.