FCH-PET/CT in Primary Hyperparathyroidism With Discordant/Negative MIBI Scintigraphy and Ultrasonography.

The contribution of [18F]F-fluorocholine (FCH)-positron emission tomography (PET)/computed tomography (CT) in normocalcemic primary hyperparathyroidism (nPHPT) remains unknown.To evaluate the sensitivity and specificity of FCH-PET/CT in a cohort of osteoporotic patients with nPHPT and discordant or negative [99mTc]Tc-sestamibi scintigraphy and ultrasonography who all underwent parathyroidectomy (PTX).Longitudinal retrospective cohort study in patients referred for osteoporosis with mild biological primary hyperparathyroidism.Tertiary referral center with expertise in bone metabolism and surgical management of hyperparathyroidism.Among 109 patients with PHPT analyzed, 3 groups were individualized according to total serum calcium (tCa) and ionized calcium (iCa): 32 patients with hypercalcemia (HtCa group), 39 patients with normal tCa and elevated iCa (NtCa group), and 38 patients with both normal tCa and iCa (NiCa). All patients had biochemical follow-up confirming or not the success of PTX.To evaluate the performance of FCH-PET/CT in terms of sensitivity and specificity, and to compare with first-line imaging procedures in the setting of nPHPT.The sensitivity of FCH-PET/CT was 67% in the hypercalcemic group, 48% in the NtCa group (P = .05 vs HtCa), and 33% in the NiCa group (P = .004 vs HtCa). Specificity ranged from 97% to 99%. FCH-PET/CT was positive in 64.3% of patients with negative conventional imaging, with biochemical resolution after PTX in 77.8% of patients. Triple negative imaging was observed in 20 patients, with PHPT resolution in 85% of these patients.This study highlights the contribution of FCH-PET/CT in a well-phenotyped cohort of normocalcemic patients with discordant or negative findings in [99mTc]Tc-sestamibi scintigraphy and ultrasonography. However, negative imaging in nPHPT does not rule out the possibility of surgical cure by an experienced surgeon.

Duke Scholars

Author Alessandro Martinino