High capacity of ultrasound for locating parathyroid adenomas in endocrinology (the ETIEN 4 study).

Abstract Objective To assess the diagnostic performance of neck ultrasound examination performed by endocrinologists to locate parathyroid adenomas in patients with primary hyperparathyroidism (PHPT). Methodology A retrospective observational study in 135 patients (mean age, 60.0 ± 12.3 years; 74.8% females) seen at endocrinology for PHPT (mean calcium level, 11.3 ± 1.2 mg/dl and mean PTH level, 240.4 ± 346.8 pg/ml) who underwent neck ultrasound examinations at the endocrinology department. 99mTc-MIBI parathyroid scintigraphy was performed before surgery in all patients. Sensitivity, specificity, positive predictive value, and negative predictive value were calculated in surgical patients. Results Ninety-eight patients underwent surgery for PHPT and 97.8% were cured at 6 months. Parathyroid ultrasound had a sensitivity of 85% (95% CI: 75.7%–91.2%) and a positive predictive value (PPV) of 95.2% (95% CI: 87.5%–98.4%) to locate parathyroid adenomas 1.7 ± 0.9 cm in maximum diameter (69.4% in smaller glands), showing a high correlation (r = 0.661 and r = 0.716) with maximum diameter and volume of the excised adenoma. Sixty percent of patients had nodular thyroid disease (64.2% bilateral nodules with mean maximum diameter of 1.5 ± 0.9 cm), and thyroidectomy was performed in 31.6%. The highest diagnostic performance was seen with a combination of neck ultrasound and 99mTc-MIBI scintigraphy (sensitivity: 96.8% and PPV: 95.8%). Conclusion In our area, parathyroid adenoma localization with ultrasound performed by endocrinologists has a high diagnostic yield and allows for detecting nodular thyroid disease in 60% of patients.