99Tcm sestamibi--a new agent for parathyroid imaging.

Parathyroid imaging using 99Tcm sestamibi has been carried out prior to surgery in five patients with hyperparathyroidism and the results compared with a standard preoperative localization technique using 201Tl (thallous chloride). The 99Tcm sestamibi correctly localized all abnormal glands and showed higher parathyroid to thyroid uptake in three of four parathyroid adenomas. Both agents showed localization in a thyroid adenoma. The higher uptake of sestambi and better imaging properties of its 99Tcm radiolabel means that the agent may replace thallium for routine preoperative parathyroid localization.