Initial Experience with Dual-Time-Point [18F]Flurpiridaz PET/CT for Localization of Parathyroid Adenomas in Primary Hyperparathyroidism

We aimed to evaluate the feasibility of [18F]flurpiridaz PET/CT for localization of parathyroid adenomas in patients with primary hyperparathyroidism (pHPT). Methods: Data for 11 patients with pHPT undergoing dual-time-point [18F]flurpiridaz PET/CT for localization of hyperfunctioning parathyroid glands were retrospectively analyzed. PET/CT findings were compared with results of other imaging tests, laboratory parameters, intraoperative findings, and final histology, serving as the reference standard. Results: [18F]flurpiridaz PET/CT identified parathyroid adenomas in 10 (91%) of the 11 patients studied. Parathyroid adenomas were exclusively visualized in early PET images. Uptake in adenomas declined over time (SUVmax, -65% ± 17%; P = 0.002), as did uptake in background thyroid tissue (-56% ± 16%; P = 0.002). Conclusion: [18F]flurpiridaz PET images after administration had high detection efficacy in pHPT. This work provides a rationale for larger prospective studies to evaluate the use of [18F]flurpiridaz PET/CT for localization of hyperfunctioning parathyroid glands in comparison with other imaging tests.