sensitivity and specificity of thallium-technetium subtraction scan in localization of the parathyroid adenoma [persian]

thirty one patients with biologic and clinical diagnosis of hyperparathyroidism were submitted to thalium-technetium scan prior to exploration of the neck. scan findings were compared with the pathologic results. surgical exploration of the neck showed a parathyroid adenoma in 24 patients, parathyroid carcinoma in one patient, normal parathyroid in another patient and parathyroid hyperplasia in 5 patients. ttc scan correctly detected and localized 19 out of 24(79%) of adenomas, and 7 out of 20(35%) of parathyroid hyperplasia. the scan was negative in a normal case and correctly localized a parathyroid carcinoma. five false negatives and 3 false positives were found in the adenoma group with specificity of 95.8%. scan sensitivity did not change with adenoma size and weight or serum calcium, phosporous or pth levels. in conclusion, tts is a sensitive and useful procedure for preoperative localization of parathyroid adenomas.