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-[18F]fluorocyclobutane-1-carboxylic acid ([18F]fluciclovine) positron emission tomography/X-ray computed tomography (PET/CT) in comparison to Technetium-99m 2-methoxy isobutyl isonitrile ([99mTc]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 [18F]fluciclovine (352 ± 28 MBq) injection. Lesion uptake and target-to-background ratios (TBR) were compared with [99mTc]sestamibi (798 ± 27 MBq) SPECT/CT in the same patient. RESULTS: Both techniques detected 4/5 hyperfunctioning parathyroid glands identified at surgery. The highest [18F]fluciclovine uptake and TBRs were at 5-9 min with rapid washout. [99mTc]sestamibi had significantly higher TBRs compared with [18F]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 [18F]fluciclovine PET/CT at early imaging, but conspicuity (TBR) is better with [99mTc]sestamibi. [18F]fluciclovine PET/CT does not seem promising in the detection of hyperfunctioning parathyroid glands.