The changes in irradiated salivary gland function of patients with head and neck tumors treated with radiotherapy

Abstract

Background: To investigate and analyze changes in irradiated salivary gland function of patients with head and neck tumors treated with radiotherapy. Methods: Thirty-seven patients with head and neck tumors, who received 40-70 Gy of irradiation to all major salivary glands, were analyzed. The weights of saliva secreted for 10 minutes at rest, and for 5 minutes with vitamin C stimulation, were measured. The salivary gland function was defined by the weight of saliva. Results: With vitamin C stimulation, the weight of saliva in patients whose doses were ≤50 Gy, was significantly higher than that of patients whose doses were ≥58 Gy (2.48 ± 0.33 g vs. 0.73 ± 0.18 g, P= 0.0003). When doses administered to salivary glands were ≤50 Gy, the stimulated saliva secretion recovered over time, after irradiation. However, when the doses of irradiation were ≥58 Gy, there was no recovery in saliva secretion even after a few years. Multiple regression analysis showed that age and chemotherapy may not affect salivary gland function even years after radiotherapy. Conclusion: When salivary glands were irradiated with doses ≤50 Gy, gradual recovery of salivary gland function was observed over time, whereas there was no significant recovery when the irradiation dose was >58 Gy. © 2003 Foundation for Promotion of Cancer Research.