PREOPERATIVE PARATHYROID LOCALIZATION - PROSPECTIVE EVALUATION OF TECHNETIUM 99M SESTAMIBI

The utility of preoperative parathyroid localization remains controver sial. The gold standard for identification of abnormal parathyroid gla nds is exploration of the neck by an experienced surgeon. However, bot h for the experienced and less experienced surgeon, it may be desirabl e to localize the abnormality before surgery. Such a study would not o nly direct the surgeon to the site of the lesion but also would help r educe unnecessary dissection, the number of negative explorations, and operative anesthesia time. Unfortunately, currently used noninvasive techniques including ultrasonography, thallium-technetium subtraction, computed tomography scan, and magnetic resonance imaging have had onl y limited success (35% to 78%) in demonstrating abnormal parathyroid g lands. Thirty patients with proven hyperparathyroidism were enrolled t o compare a new imaging agent, technetium 99m sestamibi, as an alterna tive to thallium 201 for subtraction scintigraphy with technetium 99m pertechnetate. Only 14 of 30 patients operated on at George Washington University underwent an identical surgical approach (exploration of a ll four glands) and had complete preoperative calcium and parathormone levels, postoperative calcium levels, and total time of surgical proc edures to formulate the basis of this report. The remaining 16 had the ir surgeries at other institutions. A surgical approach different from that used at George Washington University and unavailability of posto perative calcium levels and times of surgical procedures from these in stitutions necessitated deletion of these 16 patients from this report . Technetium 99m sestamibi-technetium 99m subtraction scans accurately localized the abnormal parathyroid gland in 13 of 14 patients, as com pared with only 9 of 14 thallium 201-technetium 99m pertechnetate subt raction scans. These results support technetium 99m sestamibi scanning as the superior modality for preoperative parathyroid localization.