engleski

F-18-fluorocholine PET/CT Imaging in Primary Hyperparathyroidism after Negative or Inconclusive Neck Ultrasound and MIBI Scintigraphy

Aim/Introduction: Primary hyperparathyroidism (PHPT) is a common endocrine disorder characterised by one or more hyperfunctioning parathyroid glands with parathyroid surgery still representing the only definitive treatment. Maximising the accuracy of imaging localisation of hyperfunctional parathyroid glands is crucial for focused and minimally invasive surgical approach. The aim of the study is to assess the value of 18F- fluorocholine positron emission tomography (PET/CT) in preoperative localization of hyperfunctioning parathyroid glands, in patients with biochemically confirmed PHPT and negative or inconclusive neck ultrasound and MIBI scintigraphy. Materials and Methods: In 136 patients (17 male, 119 female ; mean age 58 years) with PHPT (median serum calcium 2, 7 mmol/L ; median PTH 14, 6 pmol/L) PET/CT scan was performed with 100-150 MBq of 18F-fluorocholine in a period of 40 months. Low-dose PET/CT acquisition of the neck and thorax was done, 15-30 minutes post injection, 3 min per bed position. Results: In 132 patients (97%) 143 foci of increased tracer uptake suggestive of hyperactive parathyroid glands were found (single focus in 121 patients, two in 8 patients, three in 2 patients). 4 patients were PET/ CT negative, and two were judged as false positive finding after surgery. Most common localisation of the hyperactive parathyroid gland in the neck region was the level of the lower poles of thyroid lobes (40 on the right side, 44 on the left). Lesions were also found in the level of the upper poles of thyroid lobes (13 right, 17 left). In 17 patients (13%) parathyroid gland was localized prevertebraly in the neck, and in 14 patients (10%) ectopic parathyroid glands were found in the mediastinum. The average maximum diameter of the lesion was 8 mm (range 3-30 mm), and median SUV value was 5, 8 (range 1, 9-16). 66 out of 136 (48%) patients underwent surgery, and 65 parathyroid glands were removed. Histopathology confirmed parathyroid hyperplasia in 21 and adenoma in 43 removed glands. The mean PTH and Ca serum levels postoperatively dropped significantly (PTH from 14, 6 to 5, 2 pmol/L ; Ca from 2, 7 to 2, 3 mmol/L) and normalized in 54 (81%) patients. Conclusion: 18F-fluorocholine PET/CT is a fast and sensitive method for localisation of hyperactive parathyroid glands in patients with long history of PHPT, representing a substrate for minimal invasive surgery after negative or inconclusive neck ultrasound and MIBI scintigraphy and showing excellent diagnostic performance. The data about specificity will be more detailed when surgery will be completed in majority of our patients.

F-18-choline, PET/CT ; hyperparathyroidism

nije evidentirano