Feasibility of Hyperfunctioning Parathyroid Gland Localization Using [18F]fluciclovine PET/CT

Purpose To evaluate the ability of anti-1-amino-3-anti-1-amino-3-[F-18]fluorocyclobutane-1-carboxylic acid ([F-18]fluciclovine) positron emission tomography/X-ray computed tomography (PET/CT) in comparison to Technetium-99m 2-methoxy isobutyl isonitrile ([Tc-99m]sestamibi) single-photon emission computed tomography/CT (SPECT/CT) for the localization of hyperfunctioning parathyroid glands in patients with hyperparathyroidism. Procedures Four patients with hyperparathyroidism underwent 60-minutes sequential neck and thorax PET/CT after [F-18]fluciclovine (352 +/- 28 MBq) injection. Lesion uptake and target-to-background ratios (TBR) were compared with [Tc-99m]sestamibi (798 +/- 27 MBq) SPECT/CT in the same patient. Results Both techniques detected 4/5 hyperfunctioning parathyroid glands identified at surgery. The highest [F-18]fluciclovine uptake and TBRs were at 5-9 min with rapid washout. [Tc-99m]sestamibi had significantly higher TBRs compared with [F-18]fluciclovine (5-9 min) for blood pool (10.9 +/- 4.7 vs 1.3 +/- 0.6; p < 0.01) and reference muscle backgrounds (5.8 +/- 3.0 vs 1.7 +/- 0.6; p < 0.01), with non-significant trend for thyroid tissue background (1.3 +/- 0.5 vs 1.1 +/- 0.5; p = 0.73). Conclusion Hyperfunctioning parathyroid glands can be detected on [F-18]fluciclovine PET/CT at early imaging, but conspicuity (TBR) is better with [Tc-99m]sestamibi. [F-18]fluciclovine PET/CT does not seem promising in the detection of hyperfunctioning parathyroid glands.