Intraoperative Parathyroid Hormone is a Valuable Indicator of Long Term Cure in Primary Hyperparathyroidism

Abstract

Background: The use of intraoperative parathyroid hormone (ioPTH) during surgery for primary hyperparathyroidism (PHPT) has become widely available as a tool to monitor the success of the procedure. The aim of our study was to correlate the decrease of ioPTH with long term outcome in patients with PHPT.

Methods: During a 10 year period, in 137 consecutive patients with PHPT, serum PTH was measured during surgery at baseline and 5, 10 and 20 minutes after excision of the suspected parathyroid gland. Surgery was considered successful if a 50% drop in ioPTH was observed after 10 minutes. Two groups were defined - with normal (I) and above normal (II) PTH after 10 minutes. Calcium and PTH were monitored at 1.5, 3, 6 and 12 months of follow-up.

Results: Group I had significantly lower median weight of glands (1.4 vs 3.0 g), maximum pre-operative calcium (11.1 vs 11.7 mg/dL) and ioPTH at 10 minutes (30.1 vs 124.9 pg/mL) than group II - P < 0.05. Serum PTH levels at 3 and 6 months of follow-up were also significantly lower in group I than group II (55.0 vs 124.5 pg/mL and 55.9 vs 83.1 pg/mL, respectively) - P < 0.05. At 6 months, 74.3% of the patients in group I presented normal calcium and PTH, whereas in group II normal calcium and high PTH was the predominant pattern (59.1%) - P = 0.01.

Conclusions: Obtaining normalization of ioPTH during surgery is important in addition to the classic criterion of 50% decrease from baseline to predict cure of PHPT.




J Endocrinol Metab. 2013;3(4-5):98-104
doi: https://doi.org/10.4021/jem189w