Pre-operative localization and tissue uptake study in parathyroid imaging with technetium-99m-sestamibi

Background: The diagnostic ability of Tc-99m-sestamibi was compared with other techniques and the mechanism of parahtyroid uptake investigated. he mechanism of parathyroid uptake was investigated. Methods: Double-phase Tc-99m-sestamibi scanning was performed in 52 primary and 28 renal hyperparathyroidism patients. Gene expressions of mdrl and mrp were examined by reverse transcriptase polymerase chain reaction in parathyroid tissue. Results: The sensitivity of Tc-99m-sestamibi in primary and renal hyperparathyroidism was 91% and 75%, respectively, higher than for ultrasonography, Tl/Tc subtraction scintigraphy, or computed tomography. Early Tc-99m-sestamibi uptake was washed out in delayed images in 7% and 30% of glands in primary and renal hyperparathyroidism, respectively. Expression of mdrl and mrp mRNA was found in 5 of 23 and 16 of 31 glands, respectively, and their expression correlated with washout in delayed images. Conclusion: Tc-99m-sestamibi was the best localization test. mdrl and mrp were associated with Tc-99m-sestamibi washout, but their role in the parathyroid remains unclear.