Enhanced diagnostic value of 99Tcm-MIBI SPECT/CT in patients with primary hyperparathyroidism

Objective To investigate the additional diagnostic value of 99Tcm-MIBI SPECT/CT over dual-phase 99Tcm-MIBI scintigraphy in patients with primary hyperparathyroidism (PHPT). Methods Forty patients (14 males, 26 females; mean age (55.4±12.4) years) with suspicious PHPT who underwent dual-phase 99Tcm-MIBI scintigraphy and SPECT/CT from April 2008 to November 2012 were retrospectively reviewed. All patients had pathological diagnosis based on surgical resection. There were 160 parathyroid glands in 40 patients. In comparison with the result of pathological diagnosis, the diagnostic efficiency of dual-phase 99Tcm-MIBI scintigraphy and SPECT/CT were evaluated. χ2 test was used to compare the diagnostic accuracy of the 2 methods. Results Forty-three abnormal parathyroid lesions were found in 40 patients. Among the 43 lesions, 33 were diagnosed as parathyroid adenoma, and 7 were diagnosed as parathyroid hyperplasia by pathology. Using dual-phase 99Tcm-MIBI scintigraphy and SPECT/CT for the diagnosis of PHPT, the sensitivity, specificity, accuracy, negative predictive value, positive predictive value were 74.4%(32/43)vs 93.0%(40/43), 97.4%(114/117) vs 100%(117/117), 91.2%(146/160) vs 98.1%(157/160), 91.2%(114/125) vs 97.5%(117/120), 91.4%(32/35) vs 100%(40/40), respectively. The diagnostic accuracies of the above two imaging modalities were significantly different (χ2=1.125, P<0.01). Conclusion Compared with dual-phase 99Tcm-MIBI scintigraphy imaging, the diagnostic accuracy of SPECT/CT on PHPT is significantly improved. Key words: Hyperparathyroidism, primary; Tomography, emission-computed, single-photon; Tomography, X-ray computed; MIBI