Technetium 99m-MIBI-SPECT: A highly sensitive diagnostic tool for localization of parathyroid adenomas

Background. The aim of this study was to assess the value of technetium 99m -MIBI scintigraphy using the single photon emission computed tomography (SP ECT) technique for preoperative localization of smaller (less than or equal to 1 g) parathyroid adenomas. Methods. A total of 92 patients (34 men, 58 women; mean, age, 60 +/- 13 yea rs) with an established diagnosis of primary hyperparathyroidism and nondia gnostic ultrasonography (inclusion criteria) were scanned preoperatively. A fter a thyroid examination to check for other possible radionuclide-accumul ating thyroid diseases, a planar technetium 99m-pertechnetate/technetium 99 m-MIBI subtraction scintigraphy (15 minutes Post injection) and tomographic images (120 minutes Post injection) were acquired after intravenous inject ion of 740 MBq of technetium 99m-MIBI and using a 3-head gamma camera (Pick er Prism 3000). Sensitivity was defined by the ability, to predict the corr ect site of a parathyroid adenoma. Results, All patients had parathyroid adenomas less than or equal to 1 g (5 3 patients, 0.5 -1.0 g; 39 patients, < 0.5 g). Correct localization of para thyroid adenomas to one side or the other was achieved in 87% of the patien ts using planar technetium 99m-pertechnetate/technetium 99m-MIBI subtractio n scintigraphy. Sensitivity was increased to 95% by supplementary use of th e SPECT technique and a 3-D display (volume-rendered reprojection for visua lization). There was technetium 99m-MIBI accumulation in 11 benign thyroid nodes, but none of the healthy parathyroid glands were shown on the scan. Conclusions. This study indicates that technetium 99m-MIBI parathyroid scin tigraphy is a sensitive and specific tool for topographic localization even of small parathyroid adenomas, especially with the use of SPECT This metho d could help to improve the efficiency of parathyroidectomy leg; by making unilateral exploration sufficient).