Efficacy of preoperative diagnostic imaging localization of technetium 99m sestamibi scintigraphy in hyperparathyroidism

Background. Until now, preoperative parathyroid imaging has been considered unnecessary because currently available techniques do not provide any better results than an expert surgeon. We conducted a multicenter prospective study evaluating the capability of technetium 99m sestamibi scintigraphy in the preoperative identification of pathologic glands. Methods. Ninety-three patients with hyperparathyroidism, seven of them reoperative cases, were studied. In addition, 20 age-matched normocalcemic control subjects were also studied. Results. Surgical confirmation of scintigraphic images was obtained in 91 of 93 cases (sensitivity, 97.8%). In all reoperative cases (n = 7), in all cases of ectopic glands (whether operated or not; n = 6), and in all patients with a single-gland disease (n = 70), topographic identification of the pathologic gland was correct in 100%. In multiple-gland disease (n = 23), involvement of more than one gland was visualized in only 61% of the patients; however, in 91% of patients, at least one gland was localized. Surgical success-defined as postoperative normocalcemia-with this approach was 100%. All scans of normocalcemic control subjects were negative. Of 31 patients in whom a multinodular goiter coexisted, seven presented a significant radionuclide background at 120 minutes' scan. False-positive images were found together with those corresponding to the pathologic glands in only three cases. Conclusions. Tc-99m-sestamibi is a highly reliable, sensitive, and specific technique for imaging of pathologic glands in hyperparathyroidism, especially in single-gland disease. It may be considered as a first line single-procedure when a preoperative topographic diagnosis is required.