Purpose: To evaluate the usefulness and cost-effectiveness of routine preoperative technetium-99m sestamibi-iodine-123 subtraction scanning in patients with parathyroid gland disease.
Materials and methods: Tc-99m sestamibi-I-123 subtraction scanning was performed in 65 patients with primary hyperparathyroidism who were referred for evaluation before first surgery.
Results: Focal tracer uptake was detected in the mediastinum in two patients who then underwent primary sternotomy; a parathyroid adenoma, anterior to the ascending aorta, was resected in each case. In a third patient, imaging showed tracer uptake above the thyroid gland; this patient underwent resection of an undescended parathyroid adenoma located in the sheath of the right carotid artery. Initial surgery was curative in all patients. Preoperative subtraction scans depicted 56 of 59 (95%) solitary adenomas. Four patients had hyperplasia; two had double adenoma. Imaging findings indicated multiple parathyroid involvement in five of these patients and facilitated location of 12 of 15 (80%) enlarged glands. Four adenomas and two hyperplastic glands that weighed less than 100 mg were detected. The positive predictive value for any suspected location was 96%. Average surgery time was reduced from 120 to 90 minutes.
Conclusion: Preoperative subtraction scanning is useful in planning parathyroid surgery and appears to be cost-effective.