Comparative Effectiveness of Ultrasonography, 99mTc-Sestamibi, and 18F-Fluorocholine PET/CT in Detecting Parathyroid Adenomas in Patients With Primary Hyperparathyroidism

PURPOSE: Accurate preoperative localization of parathyroid lesion(s) is crucial for successful surgical management of primary hyperparathyroidism (PHPT). This study was conducted to compare the effectiveness of ultrasonography (USG) of the neck, Tc-sestamibi (MIBI) imaging with or without SPECT/CT, and F-fluorocholine (FCH) PET/CT imaging in the preoperative localization of parathyroid lesions in patients with PHPT. METHODS: Fifty-four consecutive patients with PHPT were included in this prospective study who underwent preoperative localization of the parathyroid lesion(s) using 3 diagnostic modalities followed by surgery. The sensitivity, positive predictive value, and accuracy of the 3 imaging procedures to accurately detect abnormal parathyroid glands were determined using histopathology as criterion standard with postoperative biochemical response confirmation. RESULTS: F-fluorocholine PET/CT detected 52 of 54 patients and 52 of 56 lesions with histopathologically proven parathyroid adenomas on patient-based and lesion-based analysis, respectively. Preoperative USG, MIBI, and FCH PET/CT localized abnormal parathyroid gland(s) in 39 (72.2%), 43 (79.6%), and 54 (100%) patients, respectively. The sensitivity and positive predictive value were 69.3% and 87.1% for USG, 80.7% and 97.6% for MIBI, and 100% and 96.3% for FCH PET/CT. The accuracy was 62.9%, 79.6%, and 96.3% for USG, MIBI, and FCH PET/CT, respectively, in patient-wise analysis. In 6 patients with ectopic lesions, FCH PET/CT demonstrated higher sensitivity and accuracy than MIBI and USG (100% vs 66.6% and 16.7%, respectively). CONCLUSIONS: Among the 3 imaging techniques tested simultaneously, FCH PET/CT was superior for accurate preoperative localization of parathyroid adenomas, especially for ectopic or small parathyroid lesions

[18F]Fluorocholine Uptake of Parathyroid Adenoma Is Correlated with Parathyroid Hormone Level

PURPOSE: The aim of the study was to investigate the relationship between [F]fluoromethyl-dimethyl-2-hydroxyethylammonium ([F]FCh) positron emission tomography (PET) parameters, laboratory parameters, and postoperative histopathological results in patients with primary hyperparathyroidism (pHPT) due to parathyroid adenomas. PROCEDURES: This retrospective study was conducted in 52 patients with biochemically proven pHPT. [F]FCh-PET parameters (maximum standardized uptake value: SUV in early phase (after 2 min) and late phase (after 50 min), metabolic volume, and adenoma-to-background ratio (ABR), preoperative laboratory results (PTH and serum calcium concentration), and postoperative histopathology (location, size, volume, and weight of adenoma) were assessed. Relationship of PET parameters, laboratory parameters, and histopathological parameters was assessed using the Mann-Whitney U test and Spearman correlation coefficient. MRI characteristics of parathyroid adenomas were also analyzed. RESULTS: The majority of patients underwent a PET/MR scan, 42 patients (80.7 %); 10 patients (19.3 %) underwent PET/CT. We found a strong positive correlation between late-phase SUV and preoperative PTH level (r = 0.768, p < 0.001) and between late-phase ABR and preoperative PTH level (r = 0.680, p < 0.001). The surgical specimen volume was positively correlated with the PET/MR lesion volume (r = 0.659, p < 0.001). No significant association was observed between other [F]FCh-PET parameters, laboratory parameters, and histopathological findings. Cystic adenomas were larger than non-cystic adenomas (p = 0.048). CONCLUSIONS: [F]FCh uptake of parathyroid adenomas is strongly correlated with preoperative PTH serum concentration. Therefore, the preoperative PTH level might potentially be able to predict success of [F]FCh-PET imaging in hyperparathyroidism, with higher lesion-to-background ratios being expected in patients with high PTH. PET/MR is accurate in estimating the volume of parathyroid adenomas