Abstract: 【Abstract】Objective To evaluate the value of 99m technetium-methoxyisobutyl isonitrile (^99mTc-MIBI) and single photon emission computed tomography (SPECT/CT) combined with color Doppler ultrasound in the localization of parathyroid glands in secondary hyperparathyroidism (SHPT). Methods A retrospective analysis was conducted on 442 SHPT patients (264 males and 178 females; 16～71 years old, average 45.87± 1.16 years old) from January 2010 to December 2020 treated in the Department of Thyroid and Breast Surgery, The 960th Hospital of PLA Joint Logistics Support Force (General Hospital of Jinan Military Region).
Preoperative high-frequency ultrasonography and ^99mTc-MIBI SPECT/CT were performed in SHPT patients to localize the parathyroid glands. With postoperative pathological diagnosis as the standard, the localization value of parathyroid glands in SHPT using ^99mTc-MIBI SPECT/CT, ultrasonography and their combination was evaluated. Results A total of 1,703 parathyroid glands were removed in 442 patients, in which 6 patients underwent the first operation to remove 5 parathyroid glands, 32 patients underwent the second operation, 3 patients underwent the third operation, and one patient underwent the fourth operation. The detection rates by ^99mTc-MIBI SPECT/CT fusion imaging and ultrasonography were 87.25% and 60.24%, respectively, in primary parathyroidectomy, and were 91.67% and 64.58% , respectively, in reoperation parathyroidectomy (χ2=311.785, P=0.000). The localization ability was higher by 99mTc-MIBI SPECT/CT fusion imaging than by ultrasonography. The localization rates of ^99mTc-MIBI SPECT/CT combined with ultrasonography before primary parathyroidectomy and reoperation parathyroidectomy were 90.15% and 91.67%, respectively(χ2=5.143, P=0.023), higher than those of ^99mTc-MIBI SPECT/CT fusion imaging or ultrasonography alone. Conclusion Preoperative ^99mTc-MIBI SPECT/CT fusion imaging combined with high frequency ultrasonography can accurately localize the parathyroid glands in SHPT patients. Combined use of the two methods was better than use of one method, especially for preoperative localization of the parathyroid glands in persistent and recurrent SHT.

Key words: Secondary hyperparathyroidism, ^99mTc-MIBI SPECT/CT fusion imaging, Ultrasound, Operation