Normal values of [99mTc]pertechnetate uptake and excretion fraction by major salivary glands

Abstract

The assessment of the functional status of the salivary glands has been used in the scintigraphic evaluation of xerostomia. Several quantitative methods derived from standard dynamic scintigraphy have been suggested. However, the indices proposed are quite variable and unlikely to be useful in clinical practice. The objectives of this study were to obtain reference values of major salivary glands uptake and excretion fraction in healthy subjects and to obtain normal ratios of Tc-pertechnetate uptake by the major salivary glands in comparison to the thyroid gland uptake. The standardization of these values has the purpose of making this evaluation faster and more objective. Fifty volunteers without clinical evidence of xerostomia or thyroid disease underwent static salivary glands scintigraphy with Tc-pertechnetate. Static images were obtained at 20 minutes and then at 3 minutes after oral stimulation with lemon juice. Percent uptake, excretion fraction and salivary gland to thyroid ratio rates were calculated for the parotid and the submandibular glands. The mean of the uptake values at 20 minutes for the right and left parotid glands were respectively 0.31% and 0.26%, and for the submandibular glands 0.15%. The excretion fraction of the tracer after the lemon juice stimulation was 70% for the parotids glands, 50% for the right and 49% for the left submandibular glands. The mean+/-SD salivary gland to thyroid count ratio was 0.79+/-0.45 for the right parotid, 0.78+/-0.5 for the left parotid, 0.67+/-0.33 and 0.66+/-0.34 for the right and left submandibular glands, respectively. Salivary glands scintigraphy with uptake and excretion fraction calculation is an easy to perform, non-invasive and objective method to investigate salivary glands function. These findings help the nuclear physician to interpret salivary gland scintigraphy more objectively, even in patients with thyroid gland dysfunction in whom Tc-pertechnetate thyroid uptake may be abnormal.

Normal reference values for thyroid uptake of technetium-99m pertechnetate for the Namibian population

“…On the basis of the departmental reference values, these participants would have been diagnosed as abnormal. Although these data overlap considerably with other ranges reported elsewhere, [7][8][9] they differ significantly. From the current findings, gender, age and ethnicity did not appear to significantly influence euthyroid uptake of technetium-99m pertechnetate.…”

Normal reference values for thyroid uptake of technetium-99m pertechnetate for the Namibian population

“…[7][8][9] Therefore, there is a need to establish reference values for each location.There are no reported reference values for technetium-99m pertechnetate uptake for Namibia. The reference range routinely used in Namibia for thyroid uptake of technetium-99m pertechnetate is 0.75-4% of the administered activity after 20 minutes.…”

Evaluation of the effect of isotretinoin on salivary gland function by Tc-99m pertechnetate imaging in acne vulgaris patients

“…It is well tolerated by patients because it is suitable for normal physiology (17)(18)(19)(20)(21)(22). A literature review of the quantitative evaluation of salivary gland functions created from dynamic studies showed that most functional parameters, for example percentage uptake, concentration, and excretion fractions, were generated from individual salivary gland timeactivity curves (6)(7)(8)(23)(24)(25) to acquire reference values of salivary gland uptake and excretion fraction in 50 healthy volunteers (7). In our study, evaluation of salivary gland function was performed by radionuclide imaging, and we found that there were significant decreases in the salivary gland functions of patients using isotretinoin at months 3 and 6 compared to pretreatment values.…”

“…injection. Quantitative functional data, for example uptake ratio, concentration, and excretion fraction, can be obtained via radionuclide imaging of the salivary glands (6)(7)(8). Evaluation of salivary gland function according to objective criteria, rather than subjective complaints, may provide an accurate assessment of patients taking isotretinoin and suffering from dry mouth.…”