Preoperative Imaging with [18F]-Fluorocholine PET/CT in Primary Hyperparathyroidism

Abstract

Primary hyperparathyroidism (pHPT) is a common endocrine disorder due to hyperfunctioning parathyroid glands. To date, the only curing therapy is surgical removal of the dysfunctional gland, making correct detection and localization crucial in order to perform a minimally invasive parathyroidectomy. ¹⁸F-Fluorocholine positron emission tomography/computed tomography (¹⁸F-FCH PET/CT) has shown promising results for the detection of pHPT, suggesting superiority over conventional imaging with ultrasounds or scintigraphy. A total of 33 patients with pHPT who had negative or equivocal findings in conventional imaging received ¹⁸F-FCH PET/CT preoperatively and were retrospectively included. A pathological hyperfunctional parathyroid gland was diagnosed in 24 cases (positive PET, 72.7%), 4 cases showed equivocal choline uptake (equivocal PET, 12.1%), and in 5 cases, no enhanced choline uptake was evident (negative PET, 15.2%). Twelve of the twenty-four detected adenoma patients underwent surgery, and in all cases, a pathological parathyroid adenoma was resected at the site detected by PET/CT. Two of the six patients without pathological choline uptake who received a parathyroidectomy revealed no evidence of parathyroid adenoma tissue in the histopathological evaluation. This retrospective study analyzes ¹⁸F-FCH PET/CT in a challenging patient cohort with pHPT and negative or equivocal conventional imaging results and supports the use of ¹⁸F-FCH for the diagnosis of hyperfunctional parathyroid tissue, especially in this patient setting, with a 100% true positive and true negative detection rate. Our study further demonstrates the importance of ¹⁸F-FCH PET/CT for successful surgical guidance.

Keywords: fluorocholine PET/CT; noninvasive imaging; parathyroid adenoma.

Figure 1

Patient selection flow chart.

Figure 2

Patient examples of positive (A), equivocal (B), and negative (C) ¹⁸F-Fluorocholine PET/CT; PET (1), CT (2), and fused images of PET and CT (3). (A) a focal choline uptake correlating to a contrast enhanced lesion in the caudal left thyroid bed was detectable. (B) only weak and diffused choline uptake of the right thyroid tissue was visual. (C) no enhanced choline uptake was detectable.

Figure 3

Significant positive correlation of the axial CT diameter (cm) with the SUV_max of parathyroid adenoma.

Figure 4

Laboratory results of the three groups of positive, equivocal, and negative PET/CT images. The group after successful resection showed a highly significant decrease in serum calcium and parathyroid hormone; *** = p < 0.001.