ABSTRACT

To assess and compare the diagnostic ability of ultrasound (US) and 99 mTc-MIBI planar scintigraphy in a combination with single-photon-emission computed tomography/computed tomography (SPECT/CT) for the pre-operative evaluation of primary hyperparathyroidism.

We retrospectively reviewed 60 patients who underwent parathyroidectomy for primary hyperparathyroidism. All patients had to undergo pre-operative Tc-99m MIBI planar scintigraphy+SPECT/CT and US examinations to be included in the study. All US examinations were performed by the single experienced operator. The diagnostic accuracy of the imaging methods was assessed by using the surgical pathology as a reference method.

Surgical pathology revealed solitary parathyroid adenoma in 54 patients and multiglandular disease in five patients (hyperplasia in four patients and adenoma in one patient). The sensitivity and the diagnostic accuracy of US in detecting solitary adenoma were 88.9% and 87.2%, respectively, while the sensitivity and the diagnostic accuracy of Tc-99m MIBI planar scintigraphy+SPECT/CT were 96.3% and 94.5%, respectively. However, the combination of the two methods was able to detect all solitary adenomas. The overall diagnostic accuracy of US, Tc-99m MIBI planar scintigraphy+SPECT/CT, and the combination of the modalities for solitary lesions and multiglandular disease were 86.6%, 90%, and 96.6%, respectively.

The US and Tc-99m MIBI planar scintigraphy+SPECT/CT had an excellent diagnostic ability in assessing patients with primary hyperparathyroidism in the pre-operative period; however, the combination of these methods showed even a more superior diagnostic accuracy and sensitivity, reaching up to 96.6% and 98.3, respectively. We highlight that the combination of these two methods should always be preferred in the pre-operative assessment of parathyroid adenoma.

Keywords: Hyperparathyroidism, parathyroid adenoma, parathyroid hyperplasia, ultrasound, Tc-99m MIBI-sestamibi, scintigraphy, SPECT/CT