A novel, ultrarapid parathyroid hormone assay to distinguish parathyroid from nonparathyroid tissue.

Abstract

Frozen section is the gold standard for distinguishing parathyroid tissue from lymph nodes, thyroid nodules, or fat during parathyroidectomy and thyroidectomy. Although a very accurate procedure, it can be time-consuming and costly. We hypothesize that the extremely high concentrations of parathyroid hormone (PTH) in parathyroid tissue allow for modification of a standard PTH assay that would distinguish parathyroid from nonparathyroid tissue in substantially less time than frozen section or any currently available PTH assay. A prospective, single-institution study using a modified PTH assay protocol and a manual luminometer was undertaken by testing 20 parathyroid adenomas and 9 control tissues. Analyses were performed simultaneously by the modified PTH protocol and the conventional intraoperative PTH assay. PTH luminescence values from parathyroid tissue and control tissue aspirates were significantly different at 60 seconds (P = .015). ROC curve analysis showed the assay to be 100% sensitive and 100% specific in differentiating parathyroid from nonparathyroid tissue. Our novel PTH assay accurately and reliably differentiates parathyroid from nonparathyroid tissue within 60 seconds of measurement onset. This assay provides a great advantage in time savings compared with frozen section as well as any currently existing PTH assays.