18F-NaF-PET/CT in patients with primary hyperparathyroidism and brown tumors.

Abstract

Brown tumors (BT) are non-neoplastic bone lesions infrequently occurring in patients with long-standing severe hyperparathyroidism (HPT). BT may be identified and characterized using 18-F-sodium fluoride-positron-emission-tomography/computed tomography (18F-NaF-PET/CT). We present a retrospective series of eight primary hyperparathyroidism (pHPT) patients with BT imaged with 18F-NaF-PET/CT. Imaging assessment included location, diameter, maximum standardized uptake value (SUVmax), metabolically active lesion volume (PETvol) of BT, total metabolically active bone volume (TMBvol) per patient and several computed tomography (CT) features of BT. Where appropriate, we analyzed the association between characteristic features of BT in 18F-NaF-PET/CT, histopathology, clinical symptomatology and laboratory parameters. In our cohort of 8 patients (median age, 49years, range, 26-73), 72 BT were found. The mean PETvol of BT was 89.48cm3 ± 122.81cm3 and the mean SUVmax was 17.5 ± 7.8. The total PETvol of BT per patient correlated positively with serum calcium (r = 0.810, p = 0.015), and negatively with glomerular filtration rate (GFR) (r = - 0.762, p = 0.028). TMBvol correlated significantly with serum PTH (r = 0.810, p = 0.015), alkaline phosphatase (r = 0.762, p = 0.028), and duration of postoperative hospitalization (r = 0.826, p = 0.011, 24.3days ± 19.8days). 18F-NaF-PET/CT is a valuable non-invasive whole-body imaging technique for the assessment of patients with pHPT and BT. TMBvol is associated with PTH and alkaline phosphatase, and the requirement for intense postoperative calcium substitution, which determines the duration of hospitalization.