Long-term change in the oral health related qol of patients treated with definitive radiotherapy for head and neck cancer

Summary Xerostomia is one of the most common adverse events of radiotherapy（RT）in head and neck cancer patients. The salivary glands are highly sensitive to and damaged by radiation, leading to xerostomia, which decreases patientsʼ quality of life（QOL）after radiotherapy. The purpose of this study was to evaluate long-term changes of oral health related QOL after definitive RT. Patients who were treated by RT with 60Gy or more for head and neck cancer were analyzed retrospectively. Patients with recurrence were excluded. Oral health related QOL was assessed with the General Oral Health Assessment Index（GOHAI）at follow-up dates. Sixtysix patients without recurrence were enrolled in this study. Oral health related QOL decreased rapidly during RT and recovered to the same level as normal in 3-3.5 months after the completion of RT. The nadir of GOHAI score appeared immediately after radiotherapy and the score had recovered significantly in all periods. There was no significant difference in changes in oral related QOL after RT between patients with a mean irradiated dose to the bilateral parotid glands of less than 35Gy and those of 35Gy or more.