Prospective evaluation of the efficacy of technetium 99m sestamibi and iodine 123 radionuclide imaging of abnormal parathyroid glands.

Abstract

Technetium 99m sestamibi is an isonitrile radionuclide imaging agent that, when used with subtraction iodine 123 thyroid scans, has the potential for imaging abnormal parathyroid glands. We prospectively evaluated 20 patients with hyperparathyroidism to study the efficacy of Tc 99m sestamibi and 123I subtraction radionuclide scanning for the imaging of abnormal parathyroid glands. All patients underwent neck exploration and histologic confirmation of all parathyroid glands identified. The solitary adenomas in 11 of 16 patients with primary hyperparathyroidism were localized with sestamibi scans. The scans in four of five patients with diffuse parathyroid hyperplasia showed bilateral localization consistent with enlarged glands. The fifth patient previously underwent a subtotal parathyroidectomy, and a fifth supernumerary gland was localized with the sestamibi scan. Four patients had hyperparathyroidism related to kidney disease. Three of these had bilateral localization of enlarged glands. The fourth patient had undergone two previous operations, and a fifth supernumerary gland was localized with the sestamibi scan. The preliminary data indicate that Tc 99m sestamibi in combination with 123I radionuclide scanning may be useful in the preoperative localization of abnormal parathyroid glands. This technique localized all of the solitary adenomas that were subsequently resected, and in two reoperative cases it identified the remaining solitary gland causing persistent hypercalcemia.