Salivary evaluation in radioactive I131 treated patients with thyroid carcinoma

Background and objective: radioiodine treatment (I-131) used to treat thyroid carcinomas produces side effects (sialadenitis, xerostomia, dysphagia and caries susceptibility) reflecting in a poor patient quality of life. This study aimed to evaluate the effect of I-131 on salivary function and possible oral impairment. Material and methods: Thirty-seven patients undergoing I-131 were submitted to oral examination, answer questions regarding xerostomia/hyposalivation and collect saliva at three moments (M1: 30-45 days before I-131, M2: 1-2 days after I-131 and M3: 7-10 days after treatment). Saliva was assayed for flow rate and calcium/phosphate concentrations. Results and conclusions: significant difference in calcium/phosphate concentration was shown between M1 and M2, with evident decrease at M2. Flow rate reduced right after treatment with 41% of patients returning to previous rate at M3 (no statistical difference). A higher number of patients related xerostomia and difficulty in swallowing food at M2. The results showed that xerostomia/hyposalivation, dysphagia and calcium/phosphate concentration decrease may be considered early radioiodine side effects.