DETERMINATION OF NORMAL THYROID TECHNETIUM-99M UPTAKE VALUE IN A SINGLE CENTRE PAKISTANI POPULATION

Objective: To determine the normal value of thyroid Technetium-99m uptake value in a single centre Pakistani population. Study Design: Cross-sectional study. Place and Duration of Study: Nuclear Medical Centre, Armed Forces Institute of Pathology, Rawalpindi, from Feb 2019 to Apr 2020. Methodology: A total of 90 patients who presented to Nuclear Medical Centre for parathyroid dual radiopharmaceutical scintigraphy were included in study and selected by non-probability consecutive sampling technique. Thyroid uptake studies were calculated via gamma camera acquisition. Pre injection counts were taken from the Technetium-99m pertechnetate filled syringe, thyroid counts were taken from the anterior thyroid image 20 minutes post injection and to look for any residual radiopharmaceutical counts of the empty syringe were also taken. Results: Out of total of 90 patients, 32 (35.6%) were male while 58 (64.4%) were female with male to female ratio of 1:2. The mean age was 38.4 ± 12.7. Mean Thyroid Stimulating Hormone values were 1.6 ± 0.8 and mean T4 values were 11.9 ± 3.5. The 5th-95th percentile range was 0.4-2.2% and median was 1.2%. The interquartile range was calculated to be 0.9-1.5%. Conclusion: Normal value of thyroid Technetium-99m uptake value in a single centre Pakistani population values varies significantly as compared to global figures i.e. 0.3-4.5% and is different than the one used in our own department i.e. 0.5-2.0%.