The role of dual radionuclide scintigraphy in the preoperative localization of abnormal parathyroid glands.

Success rates for neck exploration in patients with hyperparathyroidism should exceed 90 per cent in the hands of experienced surgeons. The ability to localize abnormal parathyroid glands preoperatively should maintain or increase the rate of success. Dual isotope subtraction scintigraphy using thallium-201 and technetium-99m pertechnetate offers a noninvasive means of localization. The usefulness of this procedure was studied in thirteen patients with suspected hyperparathyroidism. The scan accurately localized the site of abnormal parathyroid glands (nine adenomas and eight hyperplastic glands) in 91 per cent of the patients. Localization was most successful in adenomas weighing more than 500 mg. We conclude that dual radionuclide scintigraphy is useful in the preoperative location of enlarged parathyroid glands.