Reflux Disease in Head and Neck Cancer Patients Undergoing Radiation Therapy

The goal of this clinical research study is to learn if radiation-induced xerostomia \[RIX\] (dry mouth) causes, or worsens the effects of, acid reflux (heartburn and heartburn-like symptoms) in head and neck cancer (HNC) patients receiving radiation therapy. Objectives: Primary Objective: Determine if radiation induced xerostomia (RIX) increases the frequency or duration of acid-reflux when re-measured approximately 6-12 weeks after RT (measured by # episodes, their duration, and Reflux Area Index (RAI). Reflux Area (RA) is the sum of the area under the curve for all episodes of pH\<4 recorded during the study in units of Ph\*minutes. The Reflux area index (RAI) is the RA corrected for the duration of the study (RA x 100/study duration). Secondary Objectives: 1. To demonstrate that patients undergoing RT for OPC have reflux into the irradiated field that is anticipated to exacerbate mucositis symptoms 2. Correlate RAI and # episodes of acid reflux with salivary flow before and after RT to determine if radiation induced hyposalivation is associated with more reflux events and symptoms. 3. For patients with no pre-RT pathologic acid reflux, determine if RIX leads to conversion to acid-positive reflux measured approximately 6-12 weeks after RT. 4. Correlate office indirect laryngoscopy findings (posterior commissure thickening, cobble-stoning, granulomas, and arytenoids erythema or edema) suggestive of acid reflux in OPC patients with pH-probe findings as was done in larynx cancer (Lewin et al) 5. Compare findings from the patient reported outcome (PRO) instruments used