Preoperative localization of hyperfunctioning parathyroid glands in primary hyperparathyroidism is essential for successful parathyroid surgery, particularly in patients with previous negative imaging or reoperations.

A multicenter registry study was performed in 776 patients with primary hyperparathyroidism from 53 hospitals in Germany and Austria who underwent parathyroid surgery after preoperative ¹⁸F-choline or ¹¹C-methionine positron emission tomography/computed tomography (PET/CT).

In 683 of 776 patients (88%) (78% female, aged 15-86 years), primary hyperparathyroidism was caused by a single-gland parathyroid adenoma. A total of 9.2% patients had multiglandular disease, 0.4% had parathyroid carcinoma, and, in 2.4%, no hyperfunctional parathyroid glands were found intraoperatively. The sensitivity of ¹⁸F-choline PET/CT was 87.9% compared with 83.2% for ¹¹C-methionine PET/CT with a positive predictive value for ¹⁸F-choline PET/CT and ¹¹C-methionine PET/CT of 88.5% and 85.6%, respectively. A subgroup analysis revealed more positive results for ¹⁸F-choline PET/CT in patients with previous neck surgery (89.0%) than for ¹¹C-methionine PET/CT (74.2%, P = .0411). Positive PET/CT results significantly reduced surgery times decreasing from 93 minutes (±56.54) to 71 minutes (±43.48, P < .0001). Postoperative normalization of calcium levels was achieved in 729 patients (93.9%). In the case of positive PET/CT findings, 97.2% of the patients were cured (P < .0001).

Both PET/CT tracers showed excellent detection rates of hyperfunctioning parathyroid glands in primary hyperparathyroidism, especially in a setting with a high percentage of reoperations and negative sestamibi scans.