Streamlining of intra-operative parathyroid hormone measurements for cure during parathyroidectomy

Abstract Background The timing of intraoperative parathyroid hormone measurements during parathyroidectomy for the treatment of primary hyperparathyroidism is quite variable. Although a 50% decrease after excision is considered predictive of cure, it is not known which combination of measurements is most useful. Methods Two hundred thirteen patients underwent resection of solitary parathyroid adenomas. Sex, age, intraoperative parathyroid hormone level at baseline, before adenoma removal (T0 ), and 5 minutes (T5 ) and 10 minutes (T10 ) after adenoma removal; and 50% decrease were tested for associations with cure. Results A 50% decrease in intraoperative parathyroid hormone level was 95% sensitive for cure (95% confidence interval, 89% to 98%) but did not predict cure for individual patients. A decrease into the normal range was not correlated with cure ( P > .50). However, a 50% decrease from T0 to T10 was 97% predictive of cure (odds ratio, 6.5; P = .08). Conclusions The decrease in parathyroid hormone level from T0 to T10 during parathyroidectomy was most predictive of cure of primary hyperparathyroidism. A decrease into the normal range did not improve the performance characteristics of this test.