Salivary gland function in patients with differentiated thyroid cancer treated with high doses of radioactive iodine

Abstract

Purpose/ObjectiveXerostomia is a well-recognized adverse effect of high-dose radioactive iodine treatment. This study was undertaken to determine the extent of this effect quantitatively in patients with thyroid cancer treated with I-131.Materials/MethodsSalivary gland scintigraphy was performed with Tc-99m Pertechnetate and the excretion fraction (EF) of the glands was calculated as a measure of function; measurement was performed before iodine therapy as a baseline study, and three weeks and 3 months afterwards. Clinical evaluation was also performed using a standardized subjective questionnaire.ResultsThirty-six patients (11 males and 25 females, mean age 53 years) were studied. Mean EF at 3 weeks and 3 months after radioiodine therapy was reduced compared to baseline (base 54.9%, 3 weeks 47.25%, 3 months 44.02%, p < 0.05). Loss of function was greater in parotid gland than submandibular gland (p < 0.05), confirming the higher radiosensitivity of parotid gland. There was no significant loss of function in 12 patients (33%). More salivary gland involvement was noted with increase in radioiodine dose (p = 0.07). The relation of salivary gland functional involvement with radioiodine dose was significant in submandibular glands (p < 0.005). Functional impairment was more severe in parotid glands 3 months after iodine therapy than 3 weeks, but this difference was not significant in submandibular glands. No difference was noted between the two sexes (p = 0.6). No significant relation was noted between salivary gland functional loss and age (p = 0.1). Subjective clinical data correlated with the quantitative results.ConclusionsI -131 therapy produces a significant effect on salivary glands function which is dose-related, and is more obvious in parotid glands Purpose/ObjectiveXerostomia is a well-recognized adverse effect of high-dose radioactive iodine treatment. This study was undertaken to determine the extent of this effect quantitatively in patients with thyroid cancer treated with I-131. Xerostomia is a well-recognized adverse effect of high-dose radioactive iodine treatment. This study was undertaken to determine the extent of this effect quantitatively in patients with thyroid cancer treated with I-131. Materials/MethodsSalivary gland scintigraphy was performed with Tc-99m Pertechnetate and the excretion fraction (EF) of the glands was calculated as a measure of function; measurement was performed before iodine therapy as a baseline study, and three weeks and 3 months afterwards. Clinical evaluation was also performed using a standardized subjective questionnaire. Salivary gland scintigraphy was performed with Tc-99m Pertechnetate and the excretion fraction (EF) of the glands was calculated as a measure of function; measurement was performed before iodine therapy as a baseline study, and three weeks and 3 months afterwards. Clinical evaluation was also performed using a standardized subjective questionnaire. ResultsThirty-six patients (11 males and 25 females, mean age 53 years) were studied. Mean EF at 3 weeks and 3 months after radioiodine therapy was reduced compared to baseline (base 54.9%, 3 weeks 47.25%, 3 months 44.02%, p < 0.05). Loss of function was greater in parotid gland than submandibular gland (p < 0.05), confirming the higher radiosensitivity of parotid gland. There was no significant loss of function in 12 patients (33%). More salivary gland involvement was noted with increase in radioiodine dose (p = 0.07). The relation of salivary gland functional involvement with radioiodine dose was significant in submandibular glands (p < 0.005). Functional impairment was more severe in parotid glands 3 months after iodine therapy than 3 weeks, but this difference was not significant in submandibular glands. No difference was noted between the two sexes (p = 0.6). No significant relation was noted between salivary gland functional loss and age (p = 0.1). Subjective clinical data correlated with the quantitative results. Thirty-six patients (11 males and 25 females, mean age 53 years) were studied. Mean EF at 3 weeks and 3 months after radioiodine therapy was reduced compared to baseline (base 54.9%, 3 weeks 47.25%, 3 months 44.02%, p < 0.05). Loss of function was greater in parotid gland than submandibular gland (p < 0.05), confirming the higher radiosensitivity of parotid gland. There was no significant loss of function in 12 patients (33%). More salivary gland involvement was noted with increase in radioiodine dose (p = 0.07). The relation of salivary gland functional involvement with radioiodine dose was significant in submandibular glands (p < 0.005). Functional impairment was more severe in parotid glands 3 months after iodine therapy than 3 weeks, but this difference was not significant in submandibular glands. No difference was noted between the two sexes (p = 0.6). No significant relation was noted between salivary gland functional loss and age (p = 0.1). Subjective clinical data correlated with the quantitative results. ConclusionsI -131 therapy produces a significant effect on salivary glands function which is dose-related, and is more obvious in parotid glands I -131 therapy produces a significant effect on salivary glands function which is dose-related, and is more obvious in parotid glands