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

To assess the diagnostic performance of neck ultrasound examination performed by endocrinologists to locate parathyroid adenomas in patients with primary hyperparathyroidism (PHPT).

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±1.2mg/dL mean PTH level, 240.4±346.8pg/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.

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±0.9cm 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±0.9cm), 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%).

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.