Value of 99Tc m-MIBI SPECT/CT imaging in preoperative diagnosis of primary hyperparathyroidism and its influencing factors / 中华核医学与分子影像杂志

ABSTRACT

Objective:To investigate the preoperative diagnostic value of 99Tc m-methoxyisobutylisonitrile (MIBI) planar imaging and SPECT/CT imaging for primary hyperparathyroidism (PHPT), and analyze the relevant factors affecting the imaging results. Methods:From June 2016 to September 2019, a total of 62 patients (15 males, 47 females, age range 27-80 years) confirmed as PHPT by postsurgical pathology in Affiliated Hospital of Qingdao University were retrospectively enrolled. The diagnostic efficacies of 99Tc m-MIBI planar imaging and SPECT/CT imaging were compared using χ2 test. The differences of preoperative serum parathyroid hormone (PTH), Ca and the maximum diameter of lesion between the positive and negative groups of planar imaging were analyzed using independent-sample t test and Mann-Whitney U test. The region of interest (ROI) method was applied to calculate the uptake ratio of lesions to normal tissues at the early phase (T/Ne) and delayed phase (T/Nd) in positive cases of planar imaging. Pearson or Spearman correlation analysis was used to evaluate the correlation of T/Ne, T/Nd with preoperative serum PTH, Ca and the maximum diameter of lesion. The receiver operating characteristic (ROC) curves of preoperative serum PTH, Ca and positive planar imaging were drawn and the cut-off values were obtained. Results:The sensitivity of planar imaging and SPECT/CT imaging was 69.35%(43/62) and 87.10%(54/62) respectively ( χ2=5.729, P=0.017). The preoperative serum PTH, Ca levels and the maximum diameter of lesion in patients with positive planar imaging (253.32(107.00, 331.70) ng/L, 2.78(2.51, 2.87) mmol/L, (2.01±0.88) mm) were higher than those with negative planar imaging ((111.86±44.29) ng/L, (2.59±0.21) mmol/L, (1.42±0.55) mm; z values -2.802, -1.978, t=3.300, all P<0.05). T/Ne was positively correlated with preoperative serum PTH ( rs=0.511, P<0.001) and the maximum diameter of lesion ( r=0.381, P=0.012), and T/Nd was positively correlated with preoperative serum PTH ( rs=0.538, P<0.001), Ca ( rs=0.348, P=0.022) and the maximum diameter of lesion ( r=0.463, P=0.002). The area under the ROC curve between preoperative serum PTH, Ca and planar imaging was 0.725 and 0.646, respectively. Preoperative serum PTH had a better predictive value with the optimal cut-off value of 150.4 ng/L. Conclusions:Preoperative serum PTH, Ca and the maximum diameter of lesion are positively correlated with 99Tc m-MIBI uptake in PHPT patients with positive planar imaging results. When preoperative serum PTH is lower than 150.4 ng/L, planar imaging is prone to false negative. SPECT/CT imaging has a significant value in preoperative diagnosis and the combination of PTH and CT can improve the positive rate.