18F-fluorocholine PET/CT imaging in primary hyperparathyroidism after negative or inconclusive cervical ultrasonography and 99mTc-MIBI scintigraphy.

Purpose: Primary hyperparathyroidism (pHPT) is a common endocrine disorder characterized by one or more hyperfunctioning parathyroid glands. Definitive surgical treatment demands precise preoperative localisation of hyperfunctioning parathyroid tissue. The purpose of our study is to assess the value of ¹⁸F-fluorocholine positron emission tomography (PET/CT) in preoperative localisation of hyperfunctioning parathyroid glands in patients with biochemically confirmed pHPT and negative or inconclusive cervical ultrasonography and ^99mTc-MIBI scintigraphy.

Materials and methods: Our study included 167 patients with biochemically confirmed pHPT and negative or inconclusive cervical ultrasonography and ^99mTc-MIBI scintigraphy.

Results: In our study ¹⁸F-fluorocholine PET/CT detection rate was 92.81% (155/167) with 182 lesions identified. Overall sensitivity, specificity, accuracy, and positive predictive value (PPV) on a per-lesion analysis were 100%, 75%, 95.33%, and 94.74%. Ninety (90/95) lesions were ¹⁸F-fluorocholine PET/CT true positive. A total of 86 patients underwent surgical procedures in which 95 histological lesions were removed. Histology revealed 60 adenomas, 25 hyperplasias, 5 lesions described as inconclusive parathyroid tissue, benign lymph node tissue in 4 lesions and 1 false-positive lesion was follicular thyroid adenoma. After surgery, all patients had PTH serum values measured (15 min after extirpation or during immediate postoperative recovery). Mean PTH serum values in patients with successful surgery decreased by an average of 62.54% (preoperative PTH 14.74 ± 8.54 pmol/L to 6.3 ± 6.8 pmol/L).

Conclusion: ¹⁸F-fluorocholine PET/CT is an accurate, fast, and highly sensitive method for identifying the localization of overactive parathyroid glands in patients with primary hyperparathyroidism.