Are preoperative sestamibi scans useful for identifying ectopic parathyroid glands in patients with expected multigland parathyroid disease?

Background: The role of preoperative localization studies in patients with hyperparathyroidism and expected multigland disease remains poorly defined. Our study investigates the usefulness of obtaining preoperative sestamibi scans and ultrasonography of the neck in identifying ectopic glands in this group of patients.

Methods: Under Institutional Review Board approval, we performed a retrospective review of patients who underwent operation for secondary hyperparathyroidism, tertiary hyperparathyroidism, lithium-induced hyperparathyroidism, and multiple endocrine neoplasia syndrome at a tertiary institution between 2004 and 2015. We reviewed patient demographics, laboratory, radiology, pathology, and operative reports.

Results: Of 2,975 parathyroidectomies performed during this period, 154 operations were performed in 149 patients who met the criteria. Of the 149 patients, 82 (55.0%) had secondary, 31 (20.8%) had tertiary, 23 (15.4%) had lithium-induced HPT, and 13 (10.1%) had multiple endocrine neoplasia syndrome; 86 ectopic glands were identified in 64 patients (43.0%). Sensitivity for identification of ectopic glands was 29% for sestamibi scan and 7% for ultrasonography, while 89% of mediastinal glands were localized by sestamibi scans and thoracotomy, thoracoscopy, or sternotomy occurred in 4.7% of patients.

Conclusion: We found a greater rate of preoperative localization of ectopic glands than reported previously. Because the sensitivity of sestamibi for identification of ectopic glands is 23.0%, the implication of missing mediastinal glands warrants preoperative imaging.