Scintigraphy of the parathyroid glands with 99mTc-MIBI

Objective: Since about 3 years 99mTc-MIBI is used instead of 201Tl/99mTc subtraction scintigraphy for the localization of parathyroid involvement in hyperparathyroidism (HPT). The sensitivity of the new method was evaluated.

Methods: 24 patients aged between 28 and 83 years with surgically confirmed primary HPT were studied. Planar images were acquired 15 minutes and 3 hours after tracer injection. Additionally, in 9 patients dynamic images were obtained for 2 hours to study tracer kinetics.

Results: 19 out of 24 adenomas (79%) were identified correctly with 99mTc-MIBI.

Conclusions: The sensitivity of the scintigraphy using 99mTc-MIBI is in the range of the 201Tl/99mTc subtraction scintigraphy. Because of the superior logistic and the lower radiation exposure, 99mTc-MIBI can replace the 201Tl/99mTc scintigraphy in the preoperative diagnostic assessment.