COMPARISON OF DOUBLE-PHASE TC-99M-SESTAMIBI WITH I-123 TC-99M-SESTAMIBI SUBTRACTION SPECT IN HYPERPARATHYROIDISM

OBJECTIVE. Our purpose was to compare double-phase Tc-99m-sestamibi si ngle-photon emission computed tomography (SPECT) and simultaneous I-12 3-Tc-99m-sestamibi subtraction SPECT for preoperative localization of hyperfunctioning parathyroid tissue in patients with primary hyperpara thyroidism. SUBJECTS AND METHODS. Fifteen patients with primary hyperp arathyroidism underwent preoperative double-phase Tc-99m-sestamibi SPE CT and simultaneous I-123-Tc-99m sestamibi subtraction SPECT imaging. At surgery, the location, weight, and histopathologic evaluation of al l identified parathyroid glands were recorded. RESULTS. At surgery, 17 parathyroid adenomas and 37 normal parathyroid glands were identified . rue sensitivity, specificity; and diagnostic accuracy for the detect ion of parathyroid adenomas were 88%, 97%, and 94%, respectively, for simultaneous I-123-Tc-99m-sestamibi subtraction SPECT and 53%, 86%, an d 76%, respectively, for double-phase Tc-99m-sestamibi SPECT. The diff erences in sensitivity and diagnostic accuracy were statistically sign ificant (p = .031 and p = .016, respectively). CONCLUSION. Compared wi th double-phase Tc-99m-sestamibi SPECT, simultaneous I-123-Tc-99m-sest amibi subtraction SPECT is a superior imaging study for the preoperati ve localization of hyperfunctioning parathyroid tissue.