PARATHYROID LOCALIZATION WITH TECHNETIUM-99M-SESTAMIBI - A PROSPECTIVE EVALUATION

BACKGROUND: The purpose of this study was to prospectively evaluate pa rathyroid localization using technetium-99m-sestamibi (MIBI). STUDY DE SIGN: Technetium-99m-sestamibi scintigraphy was performed in 124 patie nts with hyperparathyroidism and the results were correlated with seru m calcium and parathyroid hormone (PTH) levels, weight location, and p athology of parathyroid tissue, and associated thyroid abnormalities. RESULTS: Hyperparathyroidism was primary in 118 patients, secondary in four patients, and tertiary in two patients. The parathyroid patholog y was a solitary adenoma in 95 patients (77 percent), double adenoma i n five (4 percent), hyperplasia in 14 (11 percent), carcinoma in one ( 1 percent), and unconfirmed in nine (7 percent) who underwent noncurat ive parathyroidectomy. Associated thyroid disease was present in 29 (2 3 percent) patients. Fourteen patients (11 percent) had undergone prev ious parathyroid exploration. The mean calcium level was 11.4+/-0.8 mg /dL (range, 8.3 to 13.7 mg/dL) and the mean adjusted PTH level was 395 +/-702 (range, 70 to 4,331). The sensitivity and positive predictive v alue of MIBI scintigraphy were 81 and 89 percent, respectively, in pat ients with a solitary adenoma and 37 and 100 percent, respectively, in patients with multiglandular disease. The mean adjusted PTH level was big-her in patients with true-positive scans compared with false-nega tive scans (440+/-628 compared with 243+/-499, p>0.05). The mean adeno ma weight was 1,877+/-3,212 mg in patients with a true-positive scan c ompared with 485+/-296 mg with a false-negative scan (p>0.05). CONCLUS IONS: The sensitivity and positive predictive value of MIBI scintigrap hy is comparable to or better than the results reported for other loca lization procedures. Its lack of sensitivity for detection of multigla ndular disease precludes its use in lieu of routine bilateral neck exp loration in the management of patients with hyperparathyroidism.