[Diagnostic value of 4-dimensional computed tomography in preoperative localization in patients with primary...

Objective: To provide more options for preoperative localization diagnosis in patients with primary hyperparathyroidism (PHPT), the diagnostic efficacy of parathyroid 4-dimensional computed tomography (4D-CT) in patients with PHPT was evaluated. Methods: This was a single-center retrospective study including 57 patients with surgical proved PHPT. All of the patients underwent 4D-CT, ⁹⁹Tc^m -sestamibi parathyroid imaging (MIBI), and ultrasonography (US) preoperatively. The reference standard for correct localization was based on operation reports and pathology confirmation. The patients were grouped according to the preoperative serum calcium levels, tumor diameter, or ectopic lesions (yes/no), respectively. The sensitivity, specificity, positive predictive value, negative predictive value and area under the curve (AUC) of 4D-CT, MIBI and US, alone or in combination, were analyzed in total and each subgroup patients. Results: Fifty-seven patients (39 women, 18 men; mean age of 56.5 years) were evaluated, including four cases with multi-gland disease and thirteen cases with ectopic parathyroid lesions. In all the patients, similar diagnostic efficacy was found in 4D-CT (AUC: 0.943) and MIBI (AUC: 0.927), both of which were higher than that of US (AUC: 0.847) (P = 0.01 for 4D-CT vs. US; P = 0.04 for MIBI vs. US). In a subset analysis for ectopic quadrants, the diagnostic efficacy of 4D-CT was significantly higher than that of MIBI (P = 0.04) or US (P = 0.01), with the sensitivity of 100%, 69.2%, and 61.5%, and AUC of 0.989, 0.846, and 0.808 for 4D-CT, MIBI and US, respectively. Conclusions: 4D-CT has similar diagnostic efficacy for preoperative localization to MIBI in patients with PHPT, and it is superior to MIBI and US in identifying the ectopic parathyroid gland. 4D-CT can be recommended as an alternative preoperative localization method, especially when parathyroid lesions could not be precisely located by US and MIBI.