Double-phase Tc-99m-sestamibi scintigraphy in the localization of abnormal parathyroid glands

BACKGROUND: The use of preoperative imaging in patients with hyperparathyroidism remains controversial. The aim of this study is to assess the usefulness of the double-phase Tc-99m-sestamibi scintigraphy in the diagnosis of abnormal parathyroid glands in patients with primary hyperparathyroidism. PATIENTS AND METHODS: We studied 60 patients presenting with primary hyperparathyroidism who were referred to surgery; four of them had been unsuccessfully operated. Tc-99m-sestamibi scintigraphy were performed in all patients previously to surgery. Scintigrafic technique: planar imaging of the neck and thorax was done in the anterior view at 15 and 150 min postinjection of 740 MBq (20 mCi) of Tc-99m-sestamibi. RESULTS: Surgery found 57 adenomas (2.59 [SD, 5.84] g; range 0.160-40), 6 hyperplastic glands (0.34 [SD, 0.26] g) and one carcinoma 8.2 g. The Tc-99m-sestamibi was able to localize correctly 60 out of 64 lesions (55/57 adenomas, 4/6 hyperplastic glands and 1/1 carcinoma) (global sensitivity of 94%, adenomas sensitivity of 96%, positive predictive value of 97% and specificity of 98%). Isotopic imaging detected the abnormal tissue in all patients who had undergone unsuccessful previous surgery. PTH (4 [SD, 1.51] pmol/l) and calcium postoperative serum levels (2.13 [SD, 0.22] mmol/l) showed curation of all patients. CONCLUSION: Double phase parathyroid scintigraphy with Tc-99m-sestamibi is the method of choice to localize abnormal parathyroid glands.