Impact of 18F-choline PET-CT or PET-MRI on surgical strategy in patients with primary hyperparathyroidism.

BACKGROUND

Accurate preoperative localization is essential for successful, focused, minimally invasive surgery in primary hyperparathyroidism (PHPT). New imaging techniques have recently been proposed. This study evaluated the impact of 18F-choline positron emission tomography (PET)-computed tomography or 18F-choline PET-magnetic resonance imaging (FCh) in patients with negative or inconclusive results on neck ultrasonography (US) and 99mTc-sestamibi (MIBI) scintigraphy.

METHODS

Baseline biochemical characteristics (preoperative calcemia and PTH), parathyroid gland features (size and weight), preoperative imaging localization techniques accuracy, and surgical results were compared in a series of patients operated for PHPT who underwent only preoperative US and MIBI scintigraphy with concordant results (MIBI Group) or also FCh as additional imaging following US and MIBI with negative or inconclusive results (FCh Group).

RESULTS

The overall cure rate was 100% in 185 patients operated for PHPT. The overall sensitivity of imaging was 63.9% in the MIBI group (n = 116), compared with 94.4% (P < 0.001) in the FCh group (n = 69). FCh provided clear unilateral localization in 86.9% of patients, avoiding unnecessary bilateral neck exploration; in contrast, based on MIBI results, unilateral localization would have been theoretically possible in only 61.6% of patients. Compared with the MIBI group, patients in the FCh group had significantly lower preoperative calcium levels (2.71 versus 2.79 mmol/l; P = 0.012), lower preoperative parathyroid hormone levels (177 versus 250 pg/ml; P = 0.032), and smaller (17 versus 21 mm; P <0.001) and lighter (1.47 versus 2.58 g, P = 0.005) parathyroid glands removed.

CONCLUSION

FCh enables successful focused parathyroidectomy in PHPT patients with negative or inconclusive MIBI results, reducing unnecessary bilateral neck exploration in 33% of patients; it may also allow for a successful focused approach in patients with milder PHPT, characterized by lower preoperative calcium and PTH levels and smaller pathological parathyroid glands.