Comparison of Tc-MIBI and Tl/Tc Subtraction Scintigraphy in Patients with Hyperparathyroidism

Received 10/30/2002; revised 11/19/2002; accepted 12/16/2002. For correspondence or reprints contact: Hatice Uslu, M.D., Department of Nuclear Medicine, Medical School, Atatürk Universty, 25240 Erzurum, Turkey. Tel: 90-442-236-09-00, Fax: 90-442-236-08-84, E-mail: [email protected] Backgrounds: Tl/Tc-pertechnetate subtraction scintigraphy is recognized as a useful procedure in the preoperative localization of parathyroid adenomas. Tc-MIBI has recently been introduced for parathyroid imaging. The aim of this study was to compare diagnostic accuracy of parathyroid scan performed with Tc-MIBI and Tl/Tc-pertechnetate subtraction in patients with hyperparathiroidism. Methods: Twenty-one patients (17 femals and 4 males, mean age: 50 years) with a clinical and laboratory diagnosis of hyperparathyroidism were included in the study. Tl/Tc-pertechnetate subtraction and earlydelayed cervico-thoracic images of Tc-MIBI scans were performed in all patients. The results of parathyroid images obtained with Tc-MIBI were compared with those obtained with Tl/Tc-pertechnetate subtraction scintigraphy, ultrasonography and histopathological findings after surgical exploration of the neck. Results: Positive scans in the seven and negative scans in the twelve patients were showed in both imaging methods. In one case, Tc-MIBI scan was negative but Tl/Tc-pertechnetate subtraction scan was positive. In another case, while Tc-MIBI scan was positive Tl/Tc-pertechnetate subtraction scan was negative. Surgical exploration of the neck was performed in patients (n = 9) with positive Tc-MIBI and Tl/Tcpertechnetate subtraction scans. Parathyroid adenoma in 7 and hyperplasia in 2 patients were detected. Ultrasonography was also negative in 12 patients whose both scans were negative. There was one falsenegative in Tc-MIBI scan and one false-negative in Tl/Tc-pertechnetate subtraction scan. The sensitivity and the specificity of both scans were 88% and 100%, respectively. Conclusions: Both Tc-MIBI and Tl/Tc-pertechnetate subtraction scans had the same sensitivity rate for the detection of pathological parathyroid tissue. Scintigraphy is simple, safe and first step imaging technique for the detection of hyperfunctioning parathyroid glands.