Value of 18F-FCH PET/CT for Diagnosing and Differentiating Hyperplasia From Adenoma

Abstract Objective: Due to the different surgical approaches for hyperplasia and adenoma in primary hyperparathyroidism, accurate preoperative diagnosis and identification are key factors affecting the surgery. 18 F-FCH PET/CT imaging is one of the effective methods for preoperative localization of hyperparathyroidism and can quantify parathyroid function by metabolic parameters. Therefore, the aim of this study was to analyze the diagnostic and differential value of 18 F-FCH PET/CT for hyperplasia and adenoma. Methods: This was a retrospective analysis of data related to 63 patients undergoing 18 F-FCH PET/CT at the First Hospital of Chongqing Medical University between December 2017 and December 2022. All procedures were completed, and postoperative pathological data were available for all patients. Comparison of laboratory parameters such as PTH and serum calcium between different patients to assess whether hyperplasia and adenoma can be distinguished based on laboratory indices, and analysis of PET/CT diagnosis and differences in metabolic parameters based on individual parathyroid lesions.The Mann–Whitney U test and binary logistic stepwise regression analysis were also used for univariate and multivariate analyses of information related to hyperplasia and adenomas, and the indicators found to be significant on multivariate analysis were used to determine cutoff values by receiver operating characteristic analysis. Results: A total of 75 parathyroid lesions were ultimately removed postoperatively in 63 patients, including 41 hyperplasia and 34 adenoma, and multiple lesions were present simultaneously in 9 patients. There were no significant differences in laboratory parameters between the different patient groups (P > 0.05). Based on the analysis of individual lesions, the sensitivity of PET/CT for the diagnosis of hyperplasia was 68.29% and that of adenoma was 97.06%. The sensitivity of PET/CT for adenoma was significantly higher than that of hyperplasia, and the size of the lesion may be the main factor affecting the sensitivity; in terms of differences in metabolic parameters, dual-phase SUVmax, MTV and TLG were significant in univariate analysis, and multivariate analysis showed the delayed TLG (cut-off value of 6.421) was a more reliable index for differentiating hyperplasia from adenoma (P=0.002). Conclusion: The diagnostic value of 18 F-FCH PET/CT for adenoma is higher than that of hyperplasia. Delayed TLG can differentiate hyperplasia from adenoma at the imaging level and help in the selection of clinical treatment options.