Neck ultrasonography as preoperative localization of primary hyperparathyroidism with an additional role of detecting thyroid malignancy

Objective: To evaluate and compare the diagnostic performances of high-resolution ultrasonography and ^99mTc-sestamibi scintigraphy for the preoperative localization of abnormal parathyroid glands and to evaluate the ability of US for additional diagnostic roles in detecting thyroid malignancy in patients with pHPT. Materials and methods: Preoperative localization images of 115 parathyroid adenomas from high-resolution ultrasonography (US) and ^99mTc-sestamibi scintigraphy (SS) were studied from 105 patients, who had undergone parathyroidectomy. Sensitivity, accuracy, and positive predictive value were calculated for the identification of adenomas in lesions and patients for both US and SS, respectively, and US and SS diagnostic performances were compared using generalized estimating equation. Results: Preoperative imaging by both modalities localized 105 (93.8%) of the 112 parathyroid lesions confirmed at surgery and histology. Sensitivity, accuracy, and positive predictive value were 93.1% and 92.2%, 90.4% and 89.5%, and 96.9% and 96.9% by US and SS, respectively, without any statistically significant differences (P = 0.796, 0.796, 0.879). US found incidental thyroid nodules in 47 patients (47/107, 43.9%), and 7 patients (7/107, 6.5%) were confirmed to have malignancy based on pathology results (all had papillary thyroid carcinoma). Conclusion: Neck ultrasonography and ^99mTc-sestamibi scintigraphy are complementary methods of the preoperative localization of parathyroid adenomas. Neck ultrasounds add an additional thyroid gland evaluation, and can be useful in the detection of incidental thyroid gland lesions, especially malignant nodules.