Pre-operative Localisation of the Parathyroid Glands in Secondary Hyperparathyroidism: A Retrospective Cohort Study

Abstract

Complete parathyroidectomy (PTx) is essential during total PTx for secondary hyperparathyroidism (SHPT) to prevent recurrent and persistent hyperparathyroidism. Pre-operative imaging evaluations, including computed tomography (CT), ultrasonography (US), and Tc-99m sestamibi (MIBI) scans, are commonly performed. Between June 2009 and January 2016, 291 patients underwent PTx for SHPT after pre-operative evaluations involving CT, US, and MIBI scans, and the diagnostic accuracies of these imaging modalities for identifying the parathyroid glands were evaluated in 177 patients whose intact parathyroid hormone (PTH) levels were <9 pg/mL after the initial PTx. Additional PTx procedures were performed on 7 of 114 patients whose intact PTH levels were >9 ng/mL after PTx, and the diagnostic validities of the imaging modalities for the remnant parathyroid glands were evaluated. A combination of CT, US, and MIBI scans achieved the highest diagnostic accuracy (75%) for locating bilateral upper and lower parathyroid glands before initial PTx. The accuracies of CT, US, and MIBI scans with respect to locating remnant parathyroid glands before additional PTx were 100%, 28.6%, and 100%, respectively. A combination of CT, US, and MIBI scans is useful for initial PTx for SHPT, and CT and MIBI scans are useful imaging modalities for additional PTx procedures.

Figure 1

Patient flow chart. CT, computed tomography; US, ultrasonography; MIBI, Tc-99m sestamibi; PTH, parathyroid hormone; POD, post-operative day; PTx, parathyroidectomy.