Lesion based diagnostic performance of dual phase 99m Tc-MIBI SPECT/CT imaging and ultrasonography in patients with secondary hyperparathyroidism.

BACKGROUND: We aimed to evaluate the diagnostic performance of 99m Tc-MIBI SPECT/CT and ultrasonography in patients with secondary hyperparathyroidism (SHPT), and explored the factors that affect the diagnostic performance.

METHODS: 99m Tc-MIBI SPECT/CT and ultrasonography were performed in 50 patients with SHPT within 1 month before they underwent surgery. Imaging results were confirmed by the pathology. Pearson correlation analysis was used to determine the correlation of PTH level with clinical data. The optimal cutoff value for predicting positive 99m Tc-MIBI results was evaluated by ROC analysis in lesions diameter.

RESULTS: Forty-nine patients had a positive 99m Tc-MIBI imaging results and 39 patients had positive ultrasonography results. The sensitivities of 99m Tc-MIBI and ultrasonography were 98.00% and 78.00%, respectively. A total of 199 lesions were resected in 50 patients. Among them, 183 lesions were proved to be parathyroid hyperplasia. On per-lesion basis analysis, the sensitivity and specificity of 99m Tc-MIBI and ultrasonography were 59.34% and 75.00% vs 46.24% and 80.00%, respectively. The Pearson correlation analysis showed that the serum AKP and PTH level had a significant linear association (r = 0.699, P < 0.001). The lesion diameter was a statistically significant predictive factor in predicting positive 99m Tc-MIBI SPECT/CT. The optimal cutoff value for predicting positive 99m Tc-MIBI results evaluated by ROC analysis in lesions diameter was 8.05 mm.

CONCLUSION: Dual phase 99m Tc-MIBI SPECT/CT imaging had a higher sensitivity in patients with SHPT than ultrasonography. Therefore, using 99m Tc-MIBI positioning the lesion could be an effective method pre-surgical in patients with SHPT.