Value of dual-phase 99Tcm-MIBI scintigraphy in the localization and diagnosis of secondary hyperparathyroidism

Objective To explore the clinical value of dual-phase 99Tcm-MIBI scintigraphy in the localization and diagnosis of secondary hyperparathyroidism (SHPT).Methods A total of 20 patients (8 males,12 females; average age 49.6 years) with uremic SHPT who underwent parathyroidectomy from 2010 to 2013 were retrospectively analyzed.All patients underwent 99Tcm-MIBI SPECT/CT and 19 underwent color Doppler ultrasonography (CDUS).Post-excisional histopathology was considered as the gold standard.The diagnostic efficacies of 99Tcm-MIBI and CDUS for SHPT were calculated.The correlation between T/NT ratio in delayed imaging and the volume of excised parathyroid and the intact PTH (iPTH) were analyzed.x2 test,Pearson or Spearson correlation analysis were used to analyze the data.Results The sensitivity,specificity,positive predictive value,negative predictive value and accuracy of 99Tcm-MIBI SPECT/CT and CDUS in the diagnosis of SHPT were 66.67％ (44/66),100％(14/14),100％ (44/44),38.89％(14/ 36),72.50％ (58/80) and 78.19％(43/55),52.38％(11/21),81.13％(43/53),47.83(11/23),71.05％ (54/76),respectively.There were significant differences in specificity and positive predictive value (x2 =9.33,9.26,both P＜0.05),but no significant differences in the sensitivity,negative predictive value and accuracy (x2 =1.97,0.04,0.46,all P＞0.05).T/NT ratio correlated with serum iPTH and parathyroid volume (r=0.638,rs =0.571,both P＜0.05).Conclusions The specificity of 99Tcm-MIBI SPECT/CT is superior to CDUS in the diagnosis of SHPT.Dual-phase 99Tcm-MIBI SPECT/CT could locate the hyperfunctional parathyroid gland and provide the basis for surgical treatment. Key words: Hyperparathyroidism, secondary;  Radionuclide imaging;  MIBI