Clinical analysis of salivary function prior to and after faciocervical fields radiotherapy for patients with nasopharyngeal carcinoma

OBJECTIVE:To study the salivary function with quantitative 99m TcO 4 - pertechnetate salivary scintigraphy before,during and after radiotherapy for patients with nasopharyngeal carcinoma (NPC) who treated with faciocervical fields and further to analyze irradiation-induced injury in relation to radiation dose and field size.METHODS: From February to October 2003,20 NPC patients were treated with faciocervical fields radiotherapy.Uptake (UR) and excretion rate (ER) of parotid and submandibular gland were performed prior to radiotherapy,at dose of 10 Gy/5Fx,36-40 Gy/18-20Fx,and 70 Gy/35Fx.Oral dryness was observed in clinic.RESULTS: ER of parotid and submandibular gland decreased significanfly after the radiotherapy at dose of 10 Gy/5Fx and 36-40 Gy/18-20Fx as compared to that of pretherapy, and to the lowest level at dose of 70 Gy/35Fx.Oral dryness was the same.No change of UR were observed before the radiotherapy at doses of 36-40Gy/ 18-20 Fx.CONCLUSIONS: With the radiotherapy dose increasing,function of parotid and submandibular gland decreases.With the guarantee of radiotherapy quality,we should improve radiation technology to reduce the volume and dose of salivary irradiation.