A Prospective Study of Salivary Gland Function in Lymphoma Patients Receiving Head and Neck Irradiation

Purpose: To determine the radiation dose-response relationship on salivary dysfunction and quality of life (QOL) over time in patients with lymphoma receiving radiation therapy (RT) to the head and neck (H and N). Methods and Materials: We conducted a prospective study on salivary-gland function in lymphoma patients receiving RT to the H and N. Fifteen patients were enrolled on the study. Dose-volume histograms and mean doses to the salivary glands were generated. Radiation-related toxicities and H and N-specific QOL were assessed before treatment and at prespecified time points posttreatment. Factors predicting a decrement in QOL were explored using Fisher's exact test. Results: During RT, 47% of patients experienced Grade ≥ 2 acute toxicity of the salivary gland, mucous membrane, or both. QOL scores improved over time, but up to one third of patients continued to have persistent oral symptoms at 2 years. At 6 months, a mean dose to at least one of the parotids of > 31 Gy was significantly associated with persistent dry mouth (100% vs. 17%, p = 0.02) and sticky saliva (100% vs. 25%, p = 0.04); a mean dose of > 11 Gy to the minor salivary glands was significantly associated with persistent sticky saliva (100% vs. 25%, p = 0.04), although the difference was no longer significant at 1 year. Conclusions: Limiting the mean parotid dose to ≤ 31 Gy and mean minor salivary gland dose to ≤ 11 Gy in lymphoma patients treated to the H and N may help reduce the risk of subacute xerostomia.