Correlation between saliva production and quality of life measurements in head and neck cancer patients treated with intensity-modulated radiotherapy.

Purpose: To investigate the strength of correlation between measured saliva flow rates and various toxicity endpoints commonly used in head and neck cancer (HNC) treatment. Materials and Methods: All patients enrolled in a phase II study using intensity modulated radiotherapy (IMRT) for HNC treatment underwent whole mouth saliva flow measurements (stimulated and unstimulated). They were also assessed for salivary gland toxicity using Radiation Therapy Oncology Group (RTOG) late toxicity grading and 9 items representing patient-graded toxicities from 2 questionnaires (Xerostomia questionnaire and University of Washington quality of life). For each patient, saliva flow rates and quality of life (QOL) data were collected preradiotherapy (RT) and at 3 intervals post-RT (3, 6, and 12 months). Results: A total of 188 sets of coregistered data were obtained for 47 patients over a period of approximately 4 years. Saliva production and mean QOL dropped significantly immediately after RT, but there was a statistically significant recovery in both parameters between 3- and 12-month post-RT. By 12 months, post-RT the mean QOL scores had returned to pre-RT baseline, although mean stimulated saliva production remained 58% below baseline. Conclusion: Patients with HNC treated with IMRT experienced a small drop in QOL which recovered to baseline by 12 months post-RT. There was no statistically significant correlation seen between global health-related QOL scores and stimulated saliva production rates in the post-RT period.