Value of 99mTc-MIBI SPECT/CT in distinguishing between parathyroid lesions and nodular goiter.

Abstract

Hyperfunctioning parathyroid lesions require surgical resection. 99mTc-methoxyisobutylisonitrile (99mTc-MIBI) single-photon emission computed tomography/computed tomography (SPECT/CT) plays an important role in the diagnosis of parathyroid lesions. Some nodular goiters have a higher uptake of 99mTc-MIBI, which is difficult to distinguish from hyperfunctioning parathyroid lesions. This study aims to explore the value of 99mTc-MIBI SPECT/CT in the differential diagnosis of parathyroid lesions and nodular goiter. This study was a retrospective analysis. A total of 68 patients who were diagnosed as parathyroid lesions by 99mTc-MIBI SPECT/CT were enrolled, with a total of 81 lesions. According to the results of pathological examination after surgical resection, the lesions were divided into a parathyroid lesion group (n=69) and a nodular goiter group (n=12). The target maximum radioactivity count (Tmax) of all lesions was measured. The mean radioactivity count of the aortic arch was used as the background mean radioactivity count (Bmean), and the ratio of the Tmax to Bmean was calculated. The difference in Tmax/Bmean between the 2 groups was compared. The minimum, mean, and maximum of CT density in the lesion were measured. The difference of CT density between the 2 groups was compared. The receiver operating characteristic (ROC) curve of patients with parathyroid lesions and patients with nodular goiter was drawn, and the diagnostic efficacy of each CT density value was evaluated. The 99mTc-MIBI radioactive uptake in parathyroid lesions and nodular goiter lesions was significantly concentrated. The CT density values of the 2 lesions were lower than normal thyroid tissue, and the boundary between the 2 lesions and the thyroid was clear or blurred. There was no significant difference in Tmax/Bmean between the 2 groups (P=0.221). The differences in the minimum, mean and maximum of CT density between the 2 groups were statistically significant (all P<0.05). The diagnostic efficiency of maximum of CT density was the best, area under the ROC curve was 0.894 (P<0.001), the cut-off was 91 HU, the sensitivity was 83.3%, and the specificity was 94.2%. The degree of 99mTc-MIBI radiation uptake in the focus has limited value in differentiating parathyroid lesions from nodular goiter, and the maximum density of CT possesses high diagnostic efficiency.