Determination of the Normal Range for Thyroid Uptake of Technetium-99m Pertechnetate in a Turkish population

Abstract

Aim: This study aimed to determine the normal range for thyroid uptake of technetium-99m (99mTc) pertechnetate in a Turkish population. Methods: The retrospective study included 73 (54 females, 19 males) consecutive euthyroid patients, all of whom underwent thyroid scintigraphy using 99mTc-pertechnetate as a component of parathyroid scintigraphy for parathyroid adenoma localization. The value of thyroid uptake of 99mTc-pertechnetate at the 20th minute was calculated for each patient. Results: The mean patient age was 56.4±15.2 years; the mean thyroid-stimulating hormone level was 1.15±0.48 uIU/mL. The median and interquartile range values of 99mTc-pertechnetate uptake were 0.8% and 0.56–1.15%, respectively. The normal range for thyroid uptake of 99mTc-pertechnetate was determined to be 0.26–1.64%. There was a negative correlation between 99mTc-pertechnetate uptake and age (r =-0.33, p=0.002). Conclusion: We propose that our new normal range for thyroid uptake of 99mTc-pertechnetate based on significantly lower values compared with those currently in use in Turkey is appropriate for use to evaluate thyroid function in thyroid disorders in the population of Istanbul.